CONTACT! Magazine issue #78

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PO BOX 1382 Hanford CA 93232-1382 United States of America 559-584-3306 Editor@CONTACTMagazine.com

Volume 14 Number 1 May - Jun 2004

Issue #78 MISSION CONTACT! Magazine is published bi-monthly by Aeronautics Education Enterprises (AEE), an Arizona nonprofit corporation, established in 1990 to promote aeronautical education. CONTACT! promotes the experimental development, expansion and exchange of aeronautical concepts, information, and experience. In this corporate age of task specialization many individuals have chosen to seek fresh, unencumbered avenues in the pursuit of improvements in aircraft and powerplants. In so doing, they have revitalized the progress of aeronautical design, particularly in the general aviation area. Flight efficiency improvements, in terms of operating costs as well as airframe drag, have come from these efforts. We fully expect that such individual efforts will continue and that they will provide additional incentives for the advancement of aeronautics.

EDITORIAL POLICY CONTACT! pages are open to the publication of these individual efforts. Views expressed are exclusively those of the individual authors. Experimenters are encouraged to submit articles and photos of their work. Materials exclusive to CONTACT! are welcome but are returnable only if accompanied by return postage. Every effort will be made to balance articles reporting on commercial developments. Commercial advertising is not accepted. All rights with respect to reproduction, are reserved. Nothing whole or in part may be reproduced without the permission of the publisher.

Welcome to Volume 14. This is the first issue of our second year at the helm of CONTACT! Magazine. Our first year was a wild ride, with a STEEP learning curve. It started out with Sun-N-Fun 2003 and virtually zero subscribers, and by OSH 2003 we produced our first issue. OSH 2004 has come and gone, but we managed to produce 6 issues between OSH 2003 and 2004.

As you may have noticed, this issue is considerably late. At worst it should have gone out in late September, but unfortunately, by the time it was to be mailed, over half our subscribers had not yet renewed their subscriptions.

Continued on page 15 Continued on page 23

3

Jim Moye’s Ford V-6 STOL. Stretching a Tri-Pacer, converting from tricycle to conventional gear and adding a 3.8L V-6 By Dominic Brindisi and Jim Kale

6 Flying Behind an LS-1 Small Block Chevy "JUNK YARD DAWG"

by Roger P. Flower 7 An update from David Roe on his Hummel Bird "Diva" Dave solves his flutter problems reported in issue #76 By David Roe 8

Chris Christiansen's Peregrin XS-302 One person’s pursuit of excellence in his own design, built for speed and efficiency. By Pat Panzera

14 Theory of Rod Bolts and Other Prestressed Bolts

By Vance Jaqua 16 Is there Spark Ignited Heavy Fuel Engine in your future?

By Anthony J. Liberatore

SUBSCRIPTIONS Six issue subscription in U.S. funds is $24.00 for USA, $28.00 for Canada and Mexico, $40.00 for overseas air orders. CONTACT! is mailed to U.S. addresses at nonprofit organization rates mid January, March, May, July, September and November. Please allow time for processing and delivery of first issue from time of order.

17 Mazda's best kept secret, the Miller-Cycle Melineia engine

By Pat Panzera

ADDRESS CHANGES / RENEWALS The first line of your label contains the number of your last issue. Please check label for correctness. This magazine does not forward. Please notify us of your date of address change consistent with our bimonthly mailing dates to avoid missing any issues.

COPYRIGHT 2004 BY AEE, Inc.

23 An update from John Harlow on his Lancair ES Chevrolet Corvette LT -1 V-8 Engine. Also See issues #40, #53 and #66 By John Harlow

22 George Graham checks in An update from George Graham on his 13b powered canard pusher featured in issue #62 By George Graham

On the cover: Jim Moye’s Ford V-6 STOL “The Hacoda Hornet”

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Story and photos By Dominic Brindisi and Jim Kale Dom Brindisi became interested in experimental aircraft in 1972, and has assisted on a rebuild of a FlyBaby and the construction of a Spezio Tuholer (DAL1) at that time. He is currently constructing a Zenith Zodiac CH601HD which is about 75% done. Dom received his private pilots license in 1962, and has accumulated 177 hrs to date, most of which was completed in a Cessna 120 that he owned in 1970. Dominic learned to fly in a J-3 and an Aeronca 7AC Champion.

Jim Moye, Samson, Alabama. (334) 848-7848 E-mail: moye@alaweb.com Jim Moye is a member of EAA Chapter 351 and has an extensive aviation background; he once flew professionally as a forestry-fire-patrol pilot. On his rural Alabama home land, he had carved out a 2000’ runway and built a hangar. For several years he flew his straight tail Cessna 172 from this strip, but he wanted an airplane that was a little more rugged for his rural turf field.

Jim read about an airplane that the late Dave Blanton of Augusta, Kansas designed. Although it was at one time dubbed the “Javelin V6 STOL”, many pilots now call it the “FORD V6 STOL”. After pondering the design a few months, Jim decided this was the airplane for him. He and wife Jan prepared for their project by collecting parts, making preparations in the hangar, and studying the project in detail (for a great deal of time) before work on the 3 year project actually began.

Jim and his wife Jan, with their “Hacoda Hornet”.

STARTING LIFE AS A TRI-PACER This particular aircraft began life as a Piper Tri-Pacer.

Per the Blanton plans, the outboard section of the wings were lengthened two feet each, (four feet overall, increasing their original 28’ total span to 32’) making them about the same length as the original “LONG-WING” Pipers. By lengthening the outboard wing panels only, the original Tri-Pacer wing lift struts could be kept in their original configuration, with no other modifications. The wings were also modified to extend the very short TriPacer wing flaps so that they would have considerably more authority for short field takeoffs and landings. The ailerons were also modified during the wing stretch.

Of course the main gear attaching points had to be moved forward for the tail-dragger configuration. Jim installed some 33 inch “Tundra Tires” to handle rough takeoff and landing strips, and a tail wheel had to be engineered to attach to the rear fuselage.

The fuselage has been lengthened 30.25” by adding structure behind the passenger seat. This lengthening is to aid in longitudinal stability. A 3.8 liter Ford V-6 engine is installed, which uses a 2:1 belt reduction drive, which turns an 84” metal McCauley propeller, with 67” of pitch.

PERFORMANCE During cruise flight (22” MP, engine RPM @ 4200) fuel burn is reported to be about 7.7 GPH. With the stock TriPacer wing tanks, max range is about 500 miles. (Simple rule of thumb: at .5 BSFC, 7.7 GPH works out to be in the neighborhood of 95-96 horsepower. ~Pat)

The gang from EAA Chapter 351 inspecting the wing lengthening process.

At max gross weight (2200 lbs.) the ground run for takeoff is about 500’. Lightly loaded, the length is reduced to about 200’. (The empty weight is 1340 lbs). The plane also gives some very respectable climb performance. At max gross weight and 1,000 ft. MSL, the VSI is pegged at about 2,000 FPM. This is not a clean airplane so the top speed is not breath-taking. Top speed is 125 MPH indicated, and cruise is about 110 MPH indicated. Stall

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speed with full flaps is 45 MPH. Jim said that he cruises between 3800 and 4200 engine rpm, so with the 2:1 redrive, prop speeds are between 1900 and 2100 respectively. Wide open throttle, the engine spins 4600.

OIL SYSTEM

There are many noteworthy details with this engine conversion. Check the cooling fins on the oil pan extension, as well as the curved dipstick.

Jim welded on an extension to the oil pan to increase the oil capacity from the standard 5 quarts to approximately 8 quarts. Cooling fins were welded to the oil pan and an aluminum sleeve (with cooling fins) was placed over the oil filter for added protection. A liquid to liquid heat exchanger was also installed, which allows the coolant water to further reduce oil temperatures. After all of these modifications, Jim was concerned about TOO much oil cooling, so he installed an air control flap to adjust the amount of cooling air, keeping the temperature where he’s most comfortable. A lot of thought went in the system, which seems to work quite well.

ENGINE MODS Jim made a few modifications to the engine during its rebuild. The Holley 4412 carburetor received some new jets, and every nut, bolt and screw was modified to use safety wire. A mixture system was initially used, but later removed. Jim currently runs without any mixture control.

Additionally, all emission components were removed from the otherwise stock circa 1984 pushrod engine. All the other “normal” mods were included in the conversion.

THE REDRIVE Jim had a slight problem with the Blanton reduction drive right after installation. The belt wasn’t tracking correctly, so he asked Don Barnes (a machinist and a co-member of EAA Chapter 351) if he could help. Don worked his magic on the drive sprocket and the reduction drive was soon working properly.

IGNITION SYSTEM Jim added a second pickup inside the otherwise stock Ford distributor, and a second coil to give some redundancy to the ignition system. The ignition works through two stock Ford ignition modules for independent system operation. Both coils feed one set of spark plugs (using an MSD coin joiner) as a redesign of the heads for dual plugs was more complicated and expensive than Jim was prepared for. There are two batteries, a normal size battery and a small, compact size battery; they can be isolated if need be, and one used exclusively for the ignition in the event of an electrical malfunction emergency.

Jim’s 27.5” x 14” aluminum radiator is mounted diagonally inside this plenum, which is tucked away inside the section of fuselage that was lengthened.

RADIATOR Since the 3.8L Ford is a water cooled engine, it requires the use of a radiator. Jim mounted his custom Griffin “racing type” aluminum radiator diagonally, inside a custom plenum which he located in the bottom of fuselage, in the section which was lengthened. An in-flight adjustable (drop-down) air scoop is incorporated on the fuselage belly to direct the air to the radiator, allowing for warm weather or cold weather flying. The modifications to the

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liquid cooling system were more or less standard for any automotive to aviation engine adaptation. One important point was to add a bleed line from the cylinder heads back into the coolant lines. This eliminates hot spots and allows vapor to condense back into water in the system. An automotive type cabin heater was installed and Jim says it works very well on the coldest days.

The capacity of the cooling system is around 4 US gallons.

EXHAUST SYSTEM The exhaust system is simple and elegant.

Hand formed by Jim, it’s a simple set of two 3 into 1 independent systems, using a canister type collector, then a single exhaust stub. Carb heat is taken from the surrounding air at the right canister, and routed to the air cleaner in a very automotive manner.

The left canister has a bit of heat shielding on it, constructed very similar to the carb The cockpit and instrument panel is as tidy as the rest of the plane. heat collector on the opposite side. sons. Other people who are credited with helping Jim and Jan are the members of EAA chapter 351, Don FUEL SYSTEM Barnes, Jim’s good friend (and tech counselor) Alan WilAlthough this high wing aircraft has fuel tanks located in liams, as well as tech counselor Russell Sharp. the wing, which is certainly above the carburetor, gravity feed is not the only way the engine is fed. The stock mechanical fuel pump has been retained and is plumbed in line with an electric Facet fuel pump, mounted on the firewall. Takeoff and landing checklists include the use of the electric fuel pump. While in normal flight, the electric pump is shut off.

Jim’s hand made fiberglass nosebowl finishes things off quite nicely.

A LITTLE HELP FROM HIS FRIENDS Jim did not build this airplane all alone. He got a lot of help from his wife Jan. Jim said that she got involved in the project by attending a seminar on fabric covering and rib stitching. Jan did all the rib stitching on the project (it’s always nice when your spouse is supportive of your project). The plane is covered with Stits Poly-Fiber products.

Jan has named the yellow aircraft with black stripes “The Hacoda Hornet”. “Hacoda” since they live near a rural community called Hacoda, and “Hornet” for obvious rea-

As of this writing, the airplane has completed its 40 hour initial flight trials and Jim has completed the FAA paperwork, turning this “project” into a fully functional, amateur -built, experimental airplane, in accordance with the current FAA rules.

So, how does someone take a certified plane, stretch the wings and fuselage, change the landing gear configuration, and have it certificated as being “51%” amateurbuilt? Start with a set of Dave Blanton plans.

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Photos and text by Roger P. Flower badman@midsouth.rr.com

fiberglass and epoxy, working with 4130 and fabric was a welcome change. With the tail section completed and hanging in the rafters with the wings I prepared the garage for welding up the sport racer fuselage. Before I ordered the tubing a friend offered me a Sidewinder fuselage and gear legs from a project he had bought for other parts. Switching from the midwing tandem cockpit design of the Sport Racer to a low-wing side-by-side was a big change but the price was right (free) so I did it. Integrating the wings, tail, fuselage and landing gear took another two years.

Captain Roger P. Flower, USN, RET. Flew-507 combat missions in Vietnam, has 1,247 carrier landings and 7,000-hours-of flight time, mostly in jet-fighters and homebuilts. After 31 years as a Naval Aviator he worked in the aircraft maintenance departments of American Airlines and FEDEX before retiring in 2002. He is currently president of EAA Chapter 182 in Memphis, TN. In my opinion, a homebuilt aircraft project is not complete until you successfully fly it to Oshkosh. I flew my 0-320 powered Seahawk to Oshkosh in 1992, then again in 1998 after refitting it with a Ford V-6. The story about converting my Seahawk is contained in Volume II of "ALTERNATIVE ENGINES" by Mick Myal (reprinted from CONTACT! Magazine issue #44). Among the many interesting articles in Volume II, 2 stand out in my mind. One about the all aluminum small block Chevy V-8, the LS-1 and another about using a direct drive small block Chevy in a conceptual aircraft called a "JUNK YARD DAWG".

My Seahawk had provided me with 14 years of "education, entertainment and sport flying" but I was ready for a new project and the Junkyard Dog was it!

Not being a design engineer, I looked around for a set of plans to convert into the JD-1. I bought a set of "Blanton Sport Racer" plans as it was designed around the Ford V -6 which I was already familiar with and switching to the LS-1 would be easier.

THE AIRFRAME The first plans change I made was using a composite wing instead of the wooden design. I chose the Harry C. Riblett GA37U-A315 airfoil and built the wing up using laminated Mahogany &fiberglass spars with polyurethane foam and E-Glass ribs and skins. The wing phase took two years of nights and week-ends. I built the Sport Racer empennage next, and after two years of foam,

THE ENGINE Now it was time for the firewall forward, which along with the redesigned wing was the heart of the project. A new LS-1 crate engine was $5,000 from GM and used LS-l's were selling on e-Bay for about $3,500. I found a wrecked 1998 Camero and after selling everything I did not need ended up with a complete engine package for $2,900. My wife was going to get unhappy if I tried to take over her parking space in the garage so I moved all the completed components to the EAA Chapter 182 hanger and set up my half of the garage to build an engine mount and engine wire harness.

Starting with a mock-up jig of the firewall I modified the Ford V-6 engine mount plans to fit the LS-1 and Sidewinder attach points. The cast-iron block V-6 and aluminum block V-8 weighted about the same so I increased the wall thickness of the engine mount tubing one size and started welding. The forward engine mounts were fabricated from the Blanton Sport Racer plans and I used the stock LS-1 mounts for the aft engine mounts.

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COOLING SYSTEM Using the great tutorial in Vol. II on cooling liquid cooled aircraft engines, I integrated the radiator and ducts under and behind the engine. I kept it up close to the engine to simplify the design and plumbing but plan to move it back to the more aerodynamically efficient "Mustang" position in the future. Under all ground and flight conditions the engine coolant temperature has remained at thermostat setting. I use both an engine coolant temperature gauge and the readout from the ECM which I monitor in the cockpit with a hand-held computer via the OBD -II data port.

ELECTRONIC CONTROL MODULE Since 1998 all auto engines in the US. must meet OBD-II emission standards and have become a marvel of modern technology. Aircraft engines may never have to meet the rigorous standards of modern auto engines but the technology is there if they do. The stock wire harness and computer (ECM) had to be modified for aircraft instillation; Street and Performance (a shop in Mena, AR) reprogrammed the ECM to remove the anti-theft circuit and I modified the wire harness myself. At first modifying the wire harness looked a little intimidating but after buying the complete factory maintenance manuals on e-Bay and studying the wire diagrams I was able to figure out what wires to splice so that the ECM remained on the firewall in about the same location as in the auto with the engine in the aircraft backwards (flywheel forward).

The engine electrical power buss is standard aircraft wiring and I used circuit breaker switches for all circuits.

The engine electrical system looks intimidating but once you understand all the circuits it is easy to build a standard aircraft engine electrical system. The only additions I made to the stock LS-1 auto installation were to add a back-up electric fuel pump (aux. pump) and a SAFECRAFT Halon fire suppression system.

The computer controlled electronic fuel injection of the LS-1 senses mass airflow and throttle position; automatically leaning for best power (12:1) at full throttle or best economy (14.7:1) at partial throttle settings.

DIRECT DRIVE, NO PSRU To harness the horse power I installed a standard transmission flywheel and a 6" prop extension mated to a four blade, 64" diameter ground adjustable Warp Drive prop.

PERFORMANCE AND HANDLING At 3400 RPM the prop tips are at Mach .98 giving me 230 HP. I cruised up to Oshkosh from Memphis at 3,000 RPM, 120 KIAS, 4,500' MSL, with a fuel burn of 9.8 GPH. The Dog has an empty weight of 1,100 lb., a gross weight of 1,800 lbs. and carries 70 gallons of fuel. With the Dog loaded for a week of camping at AirVenture I was 100 lbs. short of max gross weight at take-off. I took off at sunrise into some patchy ground fog along the Mississippi River and climbed out at 1,700 FPM at 100 KIAS.

I have not mastered full stall landings in the Dog; the spring rod landing gear and heavy nose make bouncing very easy. She likes wheel landings at 70 KIAS so I treat her like my wife and let her have her way. Without flaps, airspeed control on final is critical to a successful landing.

With the minimal use of new parts the total cost of the JD is a little less than $10,000 plus six years of development and labor. In building the prototype Junkyard Dog I stuck to the old developer's maxim "better is the enemy of good enough"; good enough got me to AirVenture 2004 and back home!

Roger P. Flower

I want to share with you a little follow up on the flutter I experienced with my Hummel Bird “Diva�, reported in issue 76. It turns out that after filling the ailerons with the foam per the article, the demon raised it's ugly head again while I was out in Ohio with the plane. All was not well in paradise.

I think that I have it tamed once and for all this time. The idiot (yours truly) that built the counter weight arms for the static balance of the ailerons, didn't get them symmetrical. What I mean here is that the left arm (the one in question) was hanging down about an inch lower than the right aileron arm which was aimed more directly into the relative wind during straight and level flight.

With the left arm hanging down in the relative wind, it would begin to vibrate with the increased resistance of the thicker air during flight at lower altitudes, and the aileron would begin to sympathize into a flutter condition. At higher altitudes (7-8,000 feet), I never really had any problems, not to say I wasn't on the verge of having one.

Now that I have adjusted and raised the left arm even with the right arm, I have had no indications of it wanting to flutter. It now points into the wind with better penetration of the air and less resistance and susceptibility to begin vibrating. At least, that's how I see it.

I thought I should make the rest of the saga available to the readers of CONTACT!, in hopes that it might keep someone from making the same foolish mistake.

David Roe N3033L

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the exception of the flaps, which will be locked when they are in the up position, to hedge against the possible chance of flutter.

Story and photos by Pat Panzera Chris Christiansen Gilberts, Arizona 480-545-5133 www.aerostruk.com Chris Christiansen is the owner of Aerostruk and is an avid flyer with extensive time in ultralights and hang gliders. The Peregrin project is an attempt at a bit of notoriety, as Chris is bitten by the bug to set and break records. He feels that his best chance to make it into the record books is by way of the experimental powered flight category, specifically in class C-1.a/0, (661 lbs. gross takeoff weight or less). Chris has no formal education after high school, but he’s certainly not letting that stop him. At the time of our interview, this project occupied 100% of Chris’ time.

Chris studied Martin Hollmann’s books on aircraft design, which he found especially helpful in selecting aspect ratios as well as airfoil choices. A NACA 63-215 airfoil was selected for the wing of the Peregrin. This airfoil is used in some very fast aircraft like the AviaBellanca Skyrocket II, Mooney M20 series (at the root), KIS TR-1, and the ViperJet. Chris figured that it would be a good choice for his plane, as his goal is to keep the plane as fast as possible without being overly unstable. He’s looking for pitch stability, good roll control, and minimal adverse yaw.

I asked Chris about his timeline. He projects that with enough money he could easily have it up in the air in as short as three months, and that’s the main reason for publishing this article. Although we don’t usually publish articles about projects in the works, Chris needs our help. When I met Chris at Copperstate 2003, I asked him point blank why he spent money on a display if he wasn’t selling plans or kits. His answer was simple: He was looking for sponsorship. I think that Chris has a real good chance at breaking multiple records for both speed and time to climb, and has a really good start at it, so I figured I’d put this article together and see what comes of it. Hopefully we can help Chris meet his goals If you are interested in sponsoring Chris, or know someone We first met Chris at Copperstate 2003. We’ve since caught up with him who might be inagain at Copperstate 2004, and were able to update some of our photos. terested, by all Photos shot at CS-2003 show the Peregrin in grey primer. Photos where means contact the plane is in white were shot at CS-2004 him!

Chris is 24 years old, but his appearance could easily lead one to believe he’s much younger. Although he gets confused for a high schooler from time to time, his slight frame has allowed him to design a plane that’s very small and yet still easy for him to enter and exit; his size and weight will go a long way in aiding performance.

The average sized person, even by FAA standards, doesn’t stand a chance of piloting this miniature high performance airplane.

The Peregrin is essentially a mixture of a lot of different aircraft which have caught Chris’ eye in the past. He’s taken the construction methods used in plans-built composite “Rutan type” aircraft, to create solid foam core wings. He also employs moldless construction techniques to create the highly complex compound curves which give the little airplane its sleek “Lancair” appearance. The flying surfaces, as well as the retractable landing gear, are reminiscent of the early Lancair line of kit aircraft. Every control surface will be 100% balanced with

THE ENGINE The engine is a run-of-the-mill, liquid cooled, 670cc 2 cylinder, 2-stroke, 100hp (@ 6500 RPM) Rotax. It’s hard to beat the power to weight ratio of these little alternative engines, which makes it a good choice for this small plane. All the initial flights will be with this configuration, but Chris does have the option of turbocharging it for the altitude time to climb records. 6 pounds of boost (Rotax claims) is good for up to 150 horsepower for about 5 minutes. But is there room for a turbo? Yes. The turbo is slated to go in the section behind the engine compartment, where the expansion chamber currently resides.

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Description Bore Stroke Horsepower Torque Max rpm Rotation Cylinder Piston Ignition Weight

Two cycle, two cylinder, rotary valve engine, oil-in-fuel lubrication or oil pump, liquid cooled, with integrated water pump 78 mm 70 mm 105 Hp+ 80 ft. lbs.

7000 Counter-clockwise, as viewed towards the PTO 2 alloy cylinders with cast iron sleeves Aluminum cast piston with 1 piston ring CDI Approximately 110 lbs complete with carburetors, air filter, exhaust system, and manual start rewind

up. The system also unlocks with a cable and typical gas struts (used for trunk lids and rear hatches on cars) to push everything back down. A spring loaded over-thecenter position lock will hold everything in place.

The turbo (when installed) will be of the “blow through” variety, feeding the carbs with compressed air. The engine photos don’t show a PSRU, but Chris will be running a belted redux, with a ratio of 2.09:1 You can see a little glimpse of it in the photo on the previous page.

THE PROPELLER Chris is making a wood composite, 2 blade, fixed pitch propeller, with future plans to go with a cockpit controllable propeller if the need should arise. At present, a ground adjustable, 3 blade composite propeller is installed and will be used for initial flight tests. An ELLIPPSE propeller (By Grand Aero) has been donated to the cause, and after all the performance numbers are nailed down, Paul Lipps will design the propeller.

THE LANDING GEAR The gear structure, as with the dampening system, (as far as the elastomer “donuts” are concerned) as well as the trailing link, are all similar to early Lancairs; but the gear retraction system is totally Chris’ design.

A manual cable pulls everything

All the metal parts were welded by Chris, using MIG welding equipment, and were heat-treated afterwards.

“Welding is self taught which is why it’s not the prettiest thing you’ve ever seen” Chris told us, but to me, the welds look just fine. To check his work, each time he did any welding Chris would usually weld scrap material (as a test piece) of the same diameter and thickness as the finished piece, which he would later test to destruction.

THE EXHAUST SYSTEM The exhaust system is typical for a two stroke; it has a very large tuned pipe (expansion chamber), and to keep things close in around the engine (keeping frontal area to a minimum) Chris was able to run the pipe back through the engine firewall, into the fuselage, to an area between the firewall and a secondary firewall, right in front of his feet. Doing this has allowed Chris to make an augmented exhaust system, with the exhaust dumping out of the radiator ducting plenum, drawing radiator cooling air out with it. This also helps with drag reduction, as there is only one exit for both radiator cooling and exhaust. There will be a muffler in the system when it’s complete.

COOLING AIR / RADIATOR

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there is a slight shift of CG with fuel consumption. Half way through consuming the front tank, the plan is to switch to the rear if fuel is available. Chris can’t let the front tank run out all the way especially if he has baggage in the rear. 20 lbs of baggage and 4 gallons of fuel up front, with 150 pound pilot is right at the aft limit.

Should Chris find himself there, he’ll need to transfer fuel forward as soon as he can.

A sight tube is used for reading the level of the header tank, and at the moment, a sight tube is also used to read the level of the rear tank. Chris hasn’t decided yet just how he’ll read the tube behind him, but I’m sure a mirror would do the trick. Chris told me that he really has no need to check it while in flight because there’s no need to do anything but dump it all to the front. It’s not like he’ll be running off of it, or transferring only part of it.

Chris is utilizing an electric Facet automotive pump for fuel delivery, as well as a mechanical pump which comes with the Rotax engine.

The cooling air inlets straddle the nose wheel well. In the photos above the nose gear door is not installed.

Chris is using dual NACA inlets to feed his radiator, cool the exhaust pipe chamber, and to augment exhaust. The inlet air is routed around the nose wheel. The shape of the compartment which houses the radiator is somewhat venturi-like, and Chris hopes that this will aid in cooling while on the ground.

The inlet air coming in from the two NACA inlets on the underside of the nose section, as well as the two little ones (one each side of the cowl) all exit out through a small opening between the two main gear wheel wells.

(See photo at the bottom of pg. 13) After the incoming air does its chore, it’s exited out the rear and blended with the slipstream in a manner which should not add much drag.

STARTER At the time of this writing, the Peregrin had no starter.

Chris has had trouble finding an electric starter that will work for his Rotax, as all the right angle drives he can find have the starter motor clocked at either at the 1 o’clock or the 11 o’clock position. Chris needs a 12 o’clock drive (straight up and down) due to the narrow cross section of his engine compartment. “No company has been accommodating or willing to modify their starters for us; they just tell us to change our airframe.” Chris told us. “That’s not going to be happen, so now it’s starterless.”

Photo courtesy www.aerostruk.com

Since the exhaust system (expansion chamber and potentially a future turbocharger) is contained inside the fuselage, part of the inlet air is designed to help cool the compartment. With the exhaust system reaching 500 degrees, there’s real concern.

THE FUEL SYSTEM An 8 gallon header tank up front and a 4 gallon reserve tank in back makes up the 12 total gallons of fuel Chris will have onboard. The 4 gallon reserve will probably never be used, it’s just there in the event of the occasional cross country jump. When throttled back and properly leaned, Chris should have a range of about 400-450 miles, at about 250 MPH. The reserve tank is plumbed to the header via an electric pump. Filling the “reserve” tank is done by way of the return line back from the header tank. It’s plumbed with a return line, in the event that Chris ever goes with an EFI system.

With the fuel tanks not being located on or near the CG,

THE WINGS The wings are solid “blue” foam core construction, assembled around a built-up molded composite box spar.

The first thing that caught my eye about the wing is how it connected to the plane, and just how reminiscent of

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them at all. Aesthetically, these wings are a winner, no argument. Theoretically there is a drag reduction with the 60 degree swept angle.

The spar is built of “box” construction, made up of two “C” sections. It’s built primarily of “E” fiberglass with carbon rods in the corners. In Chris’s opinion, this makes for a lighter spar and about twice the strength (tensile and compression) as using unidirectional glass. “If we had used unidirectional tape for the spar caps, it would have added 20 pounds The wing spar layup being vacuum bagged. which would have been terrible”. Chris told us. The spar layup uses vacuum bagged room temperature cure epoxy.

Photo courtesy www.aerostruk.com

high performance gliders it is.

The center section is, of course, bonded to the fuselage. The outer few feet are attached by way of the wing spar (which extends beyond the root by 2-3 feet) sliding in to a rectangular socket in the center section. The spars do not overlap, but rather they miss one another by about 18 inches, tying in to the main carry-through. Access to the spar attachments is through the wheel wells. 5 bolts is all it takes to disconnect all the aileron controls and both wings.

The wing root fillet would probably be one of Chris’ favorite parts on the plane, just for pure sexiness. “It’s got a nice curve to it, but it may be aerodynamically wrong. The back curve is probably a little too high; it should be drafted a little lower.

If we run into some problems there we are going to have to chop it up and make it a little straighter and less curvy” Chris said.

The flaps have 4 positions: 0, 15, 30, and 45 degrees. Chris will probably change this as he feels there just might be too much flap angle, and 0, 10, 20, and 30 degrees seems much more appropriate to him at this point.

CANOPY Chris made his own canopy.

There has been no load testing yet; it’s all based on numbers right now and Chris plans to fly it before he does any load testing. (Chris does plan to load test it before he pulls any real g’s). The calculations show that plus or minus 6 g’s, ultimate of 9 to 9 it should work.

The plane is small enough that it might have been built with a one piece wing, permanently attached, but Chris estimates that making the wings removable as he has, maybe added 10 pounds to the empty weight. 10 pounds added to the overall weight isn’t much, but on the aircraft that only weights 300 pounds to begin with, it’s somewhat substantial. Chris feels that for ease of maintenance and ground transportation, he had to do it. “The wings detach for trailering. 7-1/2’ width. We can just put it in a trailer and take it somewhere and roll it back home; and we don’t have to fly it and abuse the aircraft. Or if it breaks down at an airport we can just drive there and pick it up and bring it back home to work on it instead of bringing everything there.” Chris told us.

The wing tips are an elliptical shape which taper back to a nice little “shark” tip. As with any wing tip design, there’s always the debate on whether it works or not.

Some are designed for drag reduction, some to increase effective span, and some just have no thought put in to

The only obvious flaw which would give away the fact that it’s home made is in an area that’s perfect for a canopy vent, which Chris plans to install. The canopy has a four pin latch system which slide through the canopy rails interconnecting two piece. Chris said, “It’s a hassle walking around the plane, but it’s a very simple system.”

CONTROLS The controls consist of a single side stick on the right, throttle and mixture on the left, with rudder pedals and toe operated brake cylinders. Chris is still undecided about which brake system to use. He’ll probably change from the nylon wheels he currently has installed, to new aluminum wheels and opt to use dual puck disc brakes.

INSTRUMENT PANEL Instrumentation will consist of a digital engine manage-

CONTACT! ISSUE 78 PAGE 11

ment system (Grand Rapids “EIS”) stripped down for ultralight use. It consists of just the basics: tachometer, water temp, OAT, highest (of the two) CHT, altimeter, VSI and highest (of the two) EGT.

THE AIRFRAME The compound curves of the plane were created by carving the actual contour out of foam blocks and massaging the shape until it was perfect.

Chris then “sealed” the foam with cellophane packing tape.

Carbon cloth then covered the “plug” which was wetted out with epoxy resin. This produced a single layer “shell”, which when cured, was pulled from the plug and placed upside-down in a cradle. The carbon can hold its shape pretty well on its own, but the cradle keeps it dimensionally stable when adding the foam to the inside. Once the foam was in place a layer of carbon (over the foam) completed the “sandwich”.

Photo courtesy

In addition to the digital screen on the EIS, the Peregrin's panel will host a whiskey compass, analog G meter and ASI, as well as an iPAQ (electronic pocket organizer or PDA) to run the Anywhere Map moving map GPS software.

CONTACT! ISSUE 78 PAGE 12

Specifications for the Peregrin XS-302 Type

Fixed wing, single place

Empty Weight

300-325lbs

Useful Load

235lbs

Gross Weight

550lbs

Normal Fuel Load

8 gallons

Full fuel Load

12 gallons

Engine, Max Power

100 HP @ 6500rpm

Propeller

2 blade fixed pitch Wing Data

Area

26 Sq Ft

Span

15.3 ft

M.A.C.

24 in

Airfoil

NACA 63-215

Aspect Ratio

6.75:1

Taper Ratio

1.67:1

Twist

2 º washout

Dihedral

5º Horizontal Tail Data

CONCLUSION Chris has put a lot of time, money, and effort into this project, and I for one would certainly like to see him succeed. But as stated previously, he needs our help. If this is something you can see yourself getting behind, I would encourage you to contact Chris and see what you can do to help.

Pat Panzera

editor@ContactMagazine.com

The small opening just above the nose wheel is the outlet for the cooling air and exhaust.

Area

6.75 Sq Ft

Span

5ft

Root Chord

18 in.

Tip Chord

12 in

Airfoil

NACA 63-009

Vertical Tail Area

4.75 Sq Ft

Landing Gear,

Retractable Tri gear

Performance, Race Weight @ Sea Level Stall Speed, with flaps

60-70 MPH

Maximum speed

270+ MPH

Max cruise speed

230-250 MPH

Rate of climb

3,000 fpm

Range

450+nm

Chris’ motto, painted on the side of the plane.

CONTACT! ISSUE 78 PAGE 13

By Vance Jaqua The connecting rod is one of the first areas of concern when ever one feels that he has overstressed his engine.

"It threw a rod" is a common cry after a disastrous engine failure, or as our British cousins would say in their often more descriptive way "I ran a big end and retired with expensive noises". We seldom truly "throw" a rod, the usual failure is that the rod to crank bearing material (the "big end") breaks down from over stress or more commonly lack of lubrication. Accelerated wear then makes a large clearance, and the remaining soft bearing material is pounded out with large clanking noises.

The highest tensile force on the rod and bolts happens when the throttle is closed at high rpm. The rod and piston are being accelerated downward at close to 700 "Gs" and the crankcase pressure (ambient or greater) is pushing upward against inlet pressure which is near zero absolute from manifold vacuum. In an engine like the Lycoming O-360 this load is probably on the order of 6000 lbs (I don't have a good number for the weight of the piston or rod, but this is probably a pretty good estimate).

The highest compressive load is near top dead center in a full throttle power stroke where the pressure can peak over 1000 psi. The acceleration of the piston and rod compensate partly for this pressure loading, but it probably peaks at a about 10000 pounds compressive load.

Now the rod bolts on an engine like this are not particularly impressive, being about a 5/16 inch thread, and a reduced section about 1/4 inch diameter (to match the thread root diameter). The load of 6000 pounds spread between the 2 bolts would correspond to a stress level, a bit over 61,000 psi. Well that is pretty scary, but isn't that bolt good for over 150,000 psi? Well, yes and no. For steady state loading that would show a safety factor of over 2, but there is that little thing called "endurance limit" for cyclic loads. This is the stress level for repetitive loads that will let you last a million cycles (ten to the sixth for you scientific notation types). For most steel alloys this value is about half the steady state value (or 150,000 is now down to 75,000). And on top of that the stress concentration factor for a standard thread form is about 3 to 1 (oops! we're down to 25,000 and in big trouble). It also might be worth mentioning that a million cycles at 2700 rpm is just a little over 6 hours (that won't get me half way to Oshkosh).

Well, it obviously works better than that--so what is the secret? The answer is preload. If a bolted joint is pre-

loaded by bolt pretension torque to a load greater than the cyclic load IT WILL NOT SEE ANY ALTERNATING LOAD AT ALL. For example if we preload the connecting rod joint to 10,000 pounds, the stress on the stretched bolt cannot increase until the tension load overcomes the locked up compression in the joint, and the surfaces start to separate. Until that point is reached, the forces will just reduce the effective compressive forces on the surface, and the bolt load stays the same. This is hard to visualize, but it is definitely true.

For example if a 200 pound man stands on a box on the floor, and you try 100 pounds worth to pick up the box.

You have reduced how hard the box is pressing on the floor but you have not increased the 200 pounds force that his feet are putting on the box. Now replace that man with a clamped down spring with 200 pounds of force, the situation is the same, as you lift on the box you do not change the force until you have lifted the box off the floor (exceeded the 200 pounds force) and are further compressing the spring. The bolts in the rod are really springs as you will see in a bit.

Bolt length changes in proportion to the load

The force is set by the compression of the spring only lifting the block and increasing compression of the spring will increase the stress in the bolt.

With a bolt it is very difficult to know how much preload you have applied. Just whip out your calibrated torque wrench you say? BZZZZZZZZ WRONG! The torque wrench is directly dependent upon the friction in the threads, and on the thrust faces of the bolt or nut, and this friction is widely influenced by a whole bag full of things - surface finish, smooth or rough - lubrication, amount or lack of it - fit of the thread - you name it and it can vary all over the map. To truly work the bolt to it's maximum potential a preload as high as 80 percent of yield is required, and trying to work to that criteria with a torque wrench can easily lead to permanent stretching

CONTACT! ISSUE 78 PAGE 14

Continued from page 2

Bolt loading is related to stretch and can only be increased if stretch is increased by exceeding preload and separating the joint.

and even cracking in the thread roots. The best method, and one that is quite common for aircraft engines is torquing to an elastic elongation value. If you have access to both ends of the bolt, and the surfaces are flat, you can measure the length of the bolt before final tightening, and measure the few thousandths of an inch of stretching that indicates the desired amount of prestress. All steel bolts have virtually the same elastic modulus 30,000,000 pounds per inch per inch. If your bolt has a working length of 2 inches a 100,000 psi prestress will lengthen it 0.0067 inches - a small number but easily read on a good micrometer. The bolts frequently have the major length reduced to roughly the same diameter as the thread root, it is just as strong (the weakest link is still the thread root diameter), and the amount of stretch is increased at the same load (because the stress is more evenly distributed along the length) for a better indication with the micrometer. If the bolt has been properly hardened, such that this load is below yield, it will act like the very stiff spring that it really is, and relax back to it's original length when unloaded, just like any other spring. If it is too soft (wrong material or improper heat treat) it will yield to this dimension, and may have a crack, just as a spring made from a wire that is not properly hardened does not return to the same length if you stretch it too much.

Many fancy systems are used to properly prestress bolts and studs which are not so easily measured as a rod bolt. Properly designed bolts can be read for length by ultrasound in blind locations. Special load measuring washers are available where an outer ring is free to spin until the design load is reached. Special bolts are available with a pin indicator built into the head. However, in most cases the designer just doubles the bolt strength (goes to the next size up) and preloads with a torque wrench to a fraction of the available working load, and just accepts the scatter in actual strength.

At the beginning of October we mailed out reminders to all our subscribers. By the looks of the response, the USPS took almost a month to deliver the letters to everyone, as we didn't get a single reply to our mailing for well in excess of 5 weeks. As of this writing, we are finally up to where we can start mailing the next subscription year, which starts with this issue. I thank each and every one of you for understanding and having patience with us, as we work through these growing pains. We have many great articles to produce in the future, and the next issue is just about ready for the printers.

And that brings me to the photo on page 2, of the odd looking bi-plane rounding the pylon at this year’s Reno Air Race. As you might recall, we published a story in the last issue of CONTACT! about the Elippse propeller. Tom Aberle used an Elippse propeller (designed specifically for Tom’s plane by Paul Lipps) to not only smoke the class, but to also break the record by over 14 MPH! In the next issue of CONTACT! we’ll bring you the full story, along with the details on how you can have an Elippse propeller designed and built for you.

Paul Lipps has announced that he and John Moyle (CONTACT! Magazine Associate Editor) have reached an agreement to design, produce, and sell Elippse propellers for experimental aircraft. Paul will be responsible for the design work, and John, along with his partner Rich Hansen, will be responsible for marketing these exciting new high performance units. The new business, operating under the name Grand Aero, intends to offer designs appropriate for the Van's RV series of aircraft first, followed by other models in short order. These propellers will be three blade ground adjustable models featuring a heavy duty aluminum hub and laminated wood blades with hard leading edge protection encased in carbon fiber coverings.

Grand Aero says we can expect to see these propellers in the hands of RV enthusiasts in as early as January of 2005. Competitive pricing is promised.

CORRECTIONS Vance Jaqua wishes to extend his apologies for the error in the table found on page 6 (of the previous issue) when he proofread the copy we sent him. The table contains a column for “Pulsar Power, Turbo 120” as an engine selection.

At this writing, neither Vance nor I know what this is, and Pulsar has not come forward with an explanation. Additionally, under the same column, the Vne is shown at 220 MPH, but the cruise speed is specified as 225 MPH. This table was taken from the Pulsar website.

We have a policy of printing only classified ads that contain a price. We recently accidentally broke this rule with our own ad, as I didn’t proof it well enough before it went to print. The ad in question has been run again in this issue (the Smith Mini Plane photo ad) and it now carries the proper pricing.

Continued on page 21

CONTACT! ISSUE 78 PAGE 15

application of Sonex’s technology in the field is a number of 2-Stroke 100cc powered UAV’s converted to run on JP-5 for the U.S. Marines. (see photo below) Sonex has two variations of there technology still in the R & D mode. With these variations, one is touted to make diesels run cleaner and the second could allow the elimination of a spark source when direct fuel injection is used while at the same time allow heavy fuel use. Note this is a small and relatively new firm and many of these projects still may need some maturation.

By Anthony J. Liberatore Images courtesy www.sonexresearch.com Imagine with today’s fuel prices, you are able to pull your aircraft up to the Jet A pump to save a little on your fuel bills. The concept is tantalizing, although I have been told it is nothing new. In order to help the war effort during WWII, some farmers would switch over to kerosene after getting the engine on their tractor warmed up. With a new war effort underway, a new military requirement has emerged that is a technology driver. This requirement is that all GPU’s, UAV’s, etc, with small engines, must run on JP-5 by 2010, in order to eliminate the logistics of carrying different fuel types into a theatre.

This requirement is driving a number of manufacturers and entrepreneurs to use their creativity and come up solutions to fill this need. Some of the current entries with some unique solutions are Evan Guy Enterprises, Dan Gurney (of racing fame), Sonex Research Inc. (not to be confused with Sonex Ltd, the kitplane manufacturer), and Mercury Marine. While there are some true diesels such as the Deltahawk that are trying to fit in and fill a given role as an UAV engine, the thrust of many of these innovators is to modify existing engines to run on “heavy fuels”. With that said we might never see general aviation applications for a long time if at all. In fact with today’ s emission regulations, any application outside the military may never come to fruition. Nevertheless, the concept is so tantalizing we cannot help but dream of what an engine this would make for our aircraft.

What they have created with these “spark ignited heavy fuel engines” is an engine that can burn a diesel type fuel without the high diesel compression ratios normally needed for the combustion process, and without the associated high engine weight required for strength. It gets even more enticing; many of the engines they are converting are two strokes, which are even lighter than the small certified engines we are accustomed too.

With that said, I would like to discuss two of the entrants and their interesting technological solutions. One of the entrants is a company out of Annapolis, Maryland: Sonex Research Inc. Sonex’s unique and patented approach uses a design that can be applied to the cylinder head or the piston. This design utilizes a center chamber that has a series of smaller chambers surrounding it (see image to the right). The outer chambers are connected to the center chamber via individual passageways. A current

Two Stroke 100cc powered UAV converted to run on JP-5 for the U.S. Marines.

Another interesting entry in this arena is the “Optimax JP” outboard engine by Mercury Marine. Mercury Marine is developing an outboard and a “jet” (both in the 200+hp class) for Navy “Seal” use. This Optimax JP is a derivative of their successful Optimax Series of outboard motors, which range from 75 hp up to 250 hp, and are direct injected two strokes. Direct injection applied to a two stroke gives the engine its inherent light weight, with 4stroke fuel consumption and emissions, as well as a more robust lower end, since the crank and rods bearings are not exposed to fuel diluted oil. These direct injected two stokes utilize Orbital Engine’s air assisted direct injection technology which atomizes the fuel droplets down to 8 microns, which is the industry benchmark. The flexibility of this system allows Mercury Marine to convert the engine to heavy fuel while maintaining 95% part compatibility with their gas burning brethren.

As you might garner, what is going on in this arena is definitely on the cutting edge. However, we as aviators and experimentors have always been on that edge when it comes to applying technologies. Perhaps a two stroke direct injected, spark ignited heavy fuel engine, with an excellent power to weight ratio and great fuel consumption specifics would drive a new generation of airframe designs. Not to mention it would be neat to taxi to the jet A fuel pump and filler up!

Anthony J. Liberatore aliberatore@comcast.net

CONTACT! ISSUE 78 PAGE 16

Mazda's unique Miller-cycle engine has been named one the world's "10 Best Engines" for four years in a row by Ward's, an automotive trade journal. Besides the hugely overlooked Miller, only two other engines have been on the Ward's Ten Best list all four years since 1995.

By Pat Panzera (with a little help from a Mazda press release) I recently became in need of a 4 door vehicle. I’ve always been a huge Mazda fan, so I found myself at the local Mazda dealer, looking at used cars. My budget put me in the (used) 4 banger Protégé market, but there was a used Millenia that caught my eye. I’ve always liked the Millenia, so I figured I’d give it a test drive, even though it was a bit of a budget buster.

The salesman told me that under the hood was a 2.3 liter V6, coupled to an automatic transmission. Weighing in at 3,487 pounds gross, I was not expecting much in the way of performance, but I was pleasantly surprised. The acceleration off the line was not too bad; but if I kept my foot in it, just a little bit, it came alive as the R’s climbed.

It was almost shocking just how much power it had in the higher RPM range. For those of you who have ever ridden 2-stroke dirt bikes, you’ll know what I mean when I say it “came on the pipe”.

SUPERCHARGER Mazda’s Miller-cycle engine uses a Lysholm compressor (a scroll-type supercharger) to boost intake pressure, along with late intake-valve timing to produce an impressive amount of power without sacrificing fuel efficiency.

The result is a vigorous 210-horsepower with the quick response of 216 foot-pounds of torque.

Power and torque figures are: 210 horsepower @ 5,500rpm and 216 ft-lbs of torque @3,500 rpm. This compares with 199 hp @ 6,500 and 164.5 ft-lbs @ 4,800 for the base 2.5 liter conventional Otto-cycle engine.

THE MILLER-CYCLE ENGINE The Miller-cycle engine looks similar to other hi-tech units: aluminum block, lots of belts, 24 valves, four camshafts, and hydraulic lifters. The exceptions are the two intercoolers and a belt driven supercharger, tucked neatly into the "Vee" between the cylinder banks.

As soon as we got back to the lot I had to pop the hood. A few seconds of staring at the conglomeration of stuff usually found under the hood of a modern front wheel drive automobile, I spied the secret to the little V-6’s impressive power: a supercharger!

THE ENGINE I instantly considered this engine a contender for aviation use (with the use of a PSRU of course), and began to research the specifics. One specification which I’m having difficulty finding is the weight, but considering its small displacement and all aluminum construction, weight shouldn’t be a serious issue.

The Millenia is no longer in production, but when it was, the engine was available in 2 versions: an N/A 2.5L 170 HP V6 for the base model, and for the top of the line Mellenia “S”, the smaller displacement, 2.3liter, quad cam, supercharged, 210 HP “Miller-cycle” V6, which was designed to perform better than larger 3.3L engines, but with the fuel efficiency of a smaller 2.0L unit.

Forged pistons, crank, and connecting rods make this one tough engine.

Note how the entire bottom half of the engine block captures the crank.

CONTACT! ISSUE 78 PAGE 17

The Miller-cycle is an interesting concept. Invented by American Ralph Miller (rather than Mazda) in the 1940’s, it changed the long-standing basic principle, the Ottocycle. Until Mazda put it in a car, the Miller-cycle principle had only been used in low engine speed applications and was first used in ships and stationary powerplants, but Mazda has had good luck with it in their Millenia.

A Miller-cycle engine is very similar to an Otto-cycle engine; it uses pistons, cams, valves, spark plugs, etc., just like an Otto-cycle engine does, but there are two major differences:  A Miller-cycle engine depends on a supercharger.  A Miller-cycle engine leaves the intake valve open during part of the compression stroke, so that the engine is compressing against the pressure of the supercharger rather than the pressure of the cylinder walls. The effect is increased efficiency, at a level of about 15 percent.

VALVE TIMING OF THE MILLER-CYCLE V6 Conventional 4 stroke engines have 4 stages in each cycle; intake, compression, combustion and exhaust.

Each cycle takes about the same length of time to complete. The Miller-cycle differs from this by delaying the closing of the intake valve, into the compression stroke.

In Mazda's Miller-cycle V6 engine, the intake valves close at 47º after BDC. This works out to be 20% of the duration of the stroke. In other words, during the first 20% of the compression stroke, the intake valves remain open and the intake air reverses direction, flowing back out of the combustion chamber before being compressed; therefore, the real effective capacity of the engine is 80% of the volume of combustion chamber. CR is decreased from 10:1 to slightly under 8:1.

that the Miller-cycle introduces. As the piston moves back up in what is normally the compression stroke, the charge is being pushed back out the normally closed valve. Typically this would lead to losing some of the needed charge, but in the Miller-cycle, the piston is in fact “over-fed” with charge from a supercharger, so blowing a bit back out is entirely planned. The supercharger typically will need to be of the positive displacement kind (due its ability to produce boost at relatively low RPM) otherwise low-rpm torque would suffer.

The key is that the valve closes, and compression stroke actually starts, only after the piston has pushed out this "extra" charge through 20% to 30% of the overall motion of the piston. In other words the compression stroke is only 70% to 80% as long as the physical motion of the piston. The piston gets 100% of the compression for 70% of the work.

The Miller-cycle "works" as long as the energy consumed by the supercharger is less than the energy needed for the piston to compress the chamber to the same pressure and volume. In general this is not the case. At higher levels of compression, the piston is more efficient than the blower. The key, however, is that at low amounts of compression, the supercharger is more efficient than the piston. Thus the Miller-cycle uses the supercharger for the portion of the compression stroke where it’s more efficient than the piston, and the piston for the portion where it’s more efficient. This leads to a reduction in the power needed to run the engine by 10% to 15%. To this end, successful production versions of the Miller-cycle have typically used variable valve timing to "switch on & off" the Miller-cycle when efficiency does not meet expectation.

In a typical spark ignition engine however, the Millercycle yields another benefit. Compressing air by the supercharger and cooling by an intercooler will net a lower intake temperature than that obtained by a higher compression ratio. This allows ignition timing to be altered to beyond what is allowed before the onset of detonation, thus increasing the overall efficiency still further.

A similar delayed valve closing is used in some modern versions of Atkinson-cycle engines but without the supercharging. Toyota Prius, super ultra low emission vehicle (SULEV), and the Ford Escape “Hybrid” SUV, uses the Atkinson-cycle to achieve their high efficiency ratings.

The traditional Otto cycle uses four strokes, two of which can be considered "high power" – the compression and combustion strokes. Much of the power lost in an engine is due to the energy needed to compress the charge during the compression stroke, so systems designed to reduce the amount of energy, or which can increase mechanical advantage, can lead to greater efficiency. In the Miller-cycle, the intake valve is left open longer than it normally would be. This is the "fifth" cycle (or stroke)

So, how does this 2.3L engine produce more power and torque using less fuel than a larger engine, without many of the expected disadvantages such as high emissions and engine knock? In simple terms, the compression stroke of the Miller-cycle engine is shortened which results in a low compression ratio, yet a high expansion ratio. In order to grasp this and other aspects of the Miller-cycle, one has to go back and have a look at some of the basic principles of internal combustion engine operation. There are five areas worth reviewing:

CONTACT! ISSUE 78 PAGE 18

pumping air in and pumping exhaust gases out (but does not include frictional losses). It is a term that describes the efficiency of bringing in and exhausting the charge. If the piston does less work in bringing and exhausting, less power robbing pumping losses are produced.

1) ENGINE SIZE VS FRICTIONAL LOSSES When the displacement of an engine is reduced, there is a reduction in frictional losses. 25% less friction is produced rotating a particular engine that has its displacement reduced by 30%. An offshoot of such downsizing is an improvement in fuel efficiency of around 10-15%.

2) STATIC VS EFFECTIVE COMPRESSION RATIO The static compression ratio is simply a comparison of the volume above the piston when it is at bottom dead center (BDC), to the volume above it at top dead center (TDC). However, in practice, the actual (effective) compression ratio is determined by the valve timing, since the real compression stroke does not begin until the intake valve closes. Similarly, the length of the power (combustion) stroke is also determined by the opening point of the exhaust valve.

With the fairly symmetrical valve timing being found in most engines these days, these two strokes are approximately the same. This means that the actual compression stroke is roughly equal to the expansion stroke.

3) THERMAL EFFICIENCY By increasing the compression ratio, the thermal efficiency of an engine is also increased. However, along with this efficiency gain comes higher combustion pressures and temperatures. These characteristics are usually accompanied by two well known "bad guys", Oxide of Nitrogen (NOx) emissions and detonation.

NOx is produced as a result of combustion pressures and temperatures greater than 2,800º F. At these temperatures the normally inert Nitrogen (78% by volume of intake air), reacts with oxygen to form oxides (nitrogen dioxide and nitrogen monoxide).

Detonation is caused when part of the air/fuel charge is ignited spontaneously by the effect of heat and pressure and not the spark plug as Otto intended.

4) PUMPING LOSSES This refers to the energy required to rotate an engine during two of the three non-power producing strokes -

One of the reasons the original Otto-cycle had the opening of the exhaust valve event brought forward (before BDC) was to allow the residual exhaust gas pressure to expel itself and not have to rely on the piston to pump it all out. Once the piston is half way down the power stroke, it’s too low to provide much push on the piston; this causes further pumping losses. The modified (Otto) valve timing allows around 50% of the exhaust gases to be expelled "for free" (no pumping losses incurred in getting rid of half of the exhaust gas). A throttled engine (cruising with low manifold pressure) has high pumping losses since a vacuum is not produced for free; energy is consumed in doing so. Some experimental variable displacement engines reduce the number of working cylinders (switching some off by holding the valves open) under low power demand conditions to reduce manifold vacuum and therefore pumping losses.

5) VOLUMETRIC EFFICIENCY “Volumetric efficiency” refers to the ability of an engine to fill its cylinders with a volume of air equal to displacement. The greater the Ve, the greater the output (torque) of that engine. Manufacturers go to great lengths to "tune" their engine design to obtain the greatest Ve. This involves research into gas flow, including manifold and port design, as well as valve timing and lift, together with multiple valves and combustion chamber design.

The easiest way to make dramatic improvements in Ve is to add an external device such as a supercharger or turbocharger. Their job is to "force feed" as much air as possible into each cylinder. But, as with increased compression ratio, excessively high combustion pressures and temperatures may be produced by forced induction.

These can work against our intent to produce a powerful but clean engine.

The most common method to overcome this problem is to use an intercooler (as well as lowering the compression ratio). An intercooler is an air-to-air heat exchanger that has the ability to reduce air intake temperature (after the supercharger) by at least 50º C. This helps keep combustion temperatures to a safe level. The modern internal combustion engine is a finely balanced mixture of all these (and many more) conflicting requirements.

SMALL ENGINE The graph at the top of the next page indicates the fuel efficiency increase as displacement is decreased. The horizontal axis begins at 1.0 which compares to a 3.3L's fuel efficiency, whilst 0.7 indicates a 30% reduction in displacement (down to 2.3L). The two curves represent the changes in efficiency gain with load changes (the greatest being at 20% load).

CONTACT! ISSUE 78 PAGE 19

the Otto-cycle engine where the relationship between the expansion and compression is the same. The late closing of the intake valve eliminates the substantial amount of energy normally required to overcome friction (as well as pumping losses), in the process of completing a normal compression stroke.

An engine that has a lower compression ratio will also naturally produce smaller amounts of friction, particularly on the compression stroke. Since the Miler engine is targeted at a vehicle that would normally use an engine over 3.0L, the reduction in size to 2.3L provides an improvement in fuel efficiency of around 13%. I’m not sure exactly how this will equate to aviation use, but it could.

REDUCED COMPRESSION STROKE RETAINING HIGH EXPANSION STROKE (RECAP) As stated before, the compression ratio would appear to be 10:1 (swept volume compared to clearance volume), however, for the first 20% of the compression stroke, the intake valves remain open. Since the actual compression stroke does not begin until the valve closes, the compression ratio is "artificially" reduced down to 8:1.

Intake valve duration is from 2º BTDC until 70º ABDC, while the exhaust valve duration is from 47º BBDC to 5º ATDC. The intake valves remain open for around an additional 30º of crankshaft rotation beyond "normal". This kind of valve timing reduces the effective compression ratio from 10:1 to a little under 8:1.

While this sounds good in theory, the usual result of blowing almost half the intake charge back out the intake valves would be a reduction in volumetric efficiency. In the Miller-cycle engine, however, this is where the compressor comes to the rescue. Any loss of intake charge through "back flow" is more than compensated for by the density (pressure) of the charge provided by the compressor. Under these circumstances, the Lysholm compressor is more efficient (lower pumping loss) at carrying out the job of filling the cylinders than a reciprocating piston.

COMBUSTION IMPROVEMENTS For many years, swirl and squish were commonly used terms to describe the in-cylinder events affecting the rate and other characteristics of combustion. In more recent years, extensive study of vertical in-cylinder swirl, called "tumble" has been carried out. On the Miller engine, the intake port has been shortened to promote smooth but strong intake air flow. A mask is added to the intake side of the combustion chamber to concentrate the air flow to the center of the cylinder; strengthening the tumble motion. Tumble promotes more ideal intake dynamics and combustion events that enhances the anti-knocking performance of the engine.

DISADVANTAGES

Mazda's Miller-cycle engine burns 13% less fuel than its 3 liter conventional sister engine. It also generates more power and a better torque curve. However, since its inUnusual is the fact that the compression stroke is retroduction in 1994 until now, no other car makers have duced but the power or expansion stroke remains the followed its trend; even Mazda itself did not produce ansame. This is one of the critical points of difference from other Miller-cycle engine. Although it is claimed to be a 2.3-liter engine, it is actually constructed as a 3-liter engine, no matter in dimensions and in material. Then, the supercharger and twin intercoolers (one per cylinder bank) will be extra costs compared with conventional 3-liter engine. For a V6, this might be forgivable, but those additional The highly efficient Lysholm compressor consists of gear driven male and female rotors, costs will be relawith three and five lobes respectively. Rotor speeds are up to 35,000rpm for the male and tively expensive for 21,000rpm for the female. Maximum discharge pressure is up to 21.76 psi. Advantages of a low cost fourthe belt driven (gear coupled) compressor includes no lag, non-contacting rotors and cylinder engine. As a result, Miller-cycle none of the temperature extremes associated with an exhaust driven turbocharger.

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concept can hardly be popular in the market where cost competitiveness is a major factor. Essentially it’s like this: Why build this complex 2.3L engine, when Mazda can build a larger, equally powerful engine for less? This may be a coffin nail for the automobile industry, but the way I look at it, the efficiencies and light weight work in favor of aviation use.

Continued from page 15 LETTERS I received the following letter, and I’m hoping the readers of CONTACT! can help.

I am embarking on creating a 20B rotary engine that can run on diesel and I would like to know of other people besides Mistral rotary and Mazda who are doing similar work.

I will be ready to start testing a motor on a dyno in the late autumn so it would be an advantage to work with like minded people. Any leads you can give me would be appreciated.

Sincerely, Douglas Fir fir@gol.com If you can help Doug out with this, please keep me in the loop. Maybe we’ll cover this topic in a future issue.

AVAILABILITY TO THE AVIATION COMMUNITY Given the age of the Millenia, they are starting to turn up in local junkyards. The Japanese domestic market (JDM) is exporting their “30,000 mile” used engines, and one can find good running used JDM versions of the Mazda Miller-cycle for $1500 - $2000 complete. Of course you’ll need the harness and the ECU, so it might be best to pull the engine from a local US wrecker, rather than buy from a JDM importer.

I personally have been looking for a bargain on a used version of this engine, mostly so that I can continue the research I’ve started, determining if this engine is a viable powerplant for experimental aviation. I’d certainly like to weigh it in A/C trim, with any and all surplus devices removed, and adding in for the PSRU. Additionally, its physical size needs to be measured and compared to other engines of the same power and weight. It just might be its overall size that makes this engine a winner or a loser.

I don’t have a particular use for the engine at the moment, but since I’m such an avid Mazda fan it would be satisfying to me to help the process along toward either seeing one of these engines in the air, or ruling it out completely as being too complex, too heavy, or too expensive to be worth the effort. Again, this all started with a test drive and a peek under the hood of a little known automobile that’s out of production.

If anyone reading this has experience with or intimate knowledge of this engine, we’d certainly like to hear about it, especially if you are already planning to install this engine in an experimental aircraft.

Pat Panzera editor@ContactMagazine.com

COMMENTS While at OSH this year, we had 2 individuals come to the booth and express their displeasure with the direction CONTACT! has gone. One was particularly upset with issue #73, and thought that we had seemingly “sold out” by publishing an issue with the entire content being Sonex related. He felt that we should be covering just engine articles, and we certainly shouldn’t be covering aviation articles that cover topics he can find in other magazines.

First I’d like to dispel the myth that CONTACT! Magazine is an “engine” magazine. It’s true that our magazine’s focus is alternative engines, but engines are nothing without the airframes they propel through the air. I would like to quote from the editorial written by Mick Myal, and published in the very first issue of CONTACT! Magazine.

“My survey of all US EAA chapters in 1987 concluded that individuals in the experimental aircraft movement desired much more information than that found in established publications. Many pointed out the lack of evaluation of new designs, inflated performance figures and the lack of impartial standardized testing. Many wanted more construction details and evaluation of existing drawings or products.

Simply put, the survey showed that the typical experimenter wanted information that is not being provided. Contact! will concentrate on these areas and subjects of specific interest to homebuilders.“ I understood this when I was a subscriber, and I certainly understood it when I took over the magazine. The “Sonex issue” as it’s become known is the epitome of this goal. We covered the plane in more detail than any other publication, or for that matter, all the other publications combined. In fact, one magazine published an article on the AeroVee engine while we were still working on our article. Their article may as well have been a reprint of their website and glossy brochure. While researching the kit engine, I drove 400 miles round trip to visit a person in the process of building his engine. John Moyle (the author of the engine article) paid a visit to their main supplier of parts.

Continued on page 24

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In issue 62, CONTACT! subscriber George Graham tells us all about his Mazda 13b powered, one-of-akind canard pusher which he designed after the Eracer. Two notable things about George’s plane are that although it appears to be a Rutan style canard pusher, it’s not made from hot-wired foam and composites, but rather it has a wooden frame and skin. In addition to this, George built his own PRSU from a stock Mazda RX-7 transmission, utilizing both the housing and the gears. In a recent e-mail conversation with George, I asked him for an update, and here’s what he wrote back: Our Mazda powered canard is working very well. We flew her to Cleveland Ohio and back last week, for a visit with some of our grandchildren. We ran into some weather in North Florida on our return flight, so we had to back-track to Valdosta Georgia for an overnight in a motel.

I have made a few improvements in the last six years of flying. I have an electric oil pump to circulate the 90w oil in the gearbox, through a small oil cooler. It helps keep the gearbox temp in check here in the 95º F heat. I also added a carb temp gage, which reads over 160º F in flight. I'll have to work on cooler intake air someday. A Navman marine fuel computer displays my fuel consumption (yes, it is 6.5 gal/hr at normal cruise). The surprise was over 10 gal/hr when down under the clouds.

My muffler cracked at a weld after five years, so I tried straight pipes. They are a bit louder, but I picked up some 200 rpm static, so I'll leave it this way.

The bird is a delight to fly, fast and comfortable. My manual transmission PSRU is working fine.

A Long-EZ flying friend of mine, who has a Lycoming O235 engine, must have some type of love/hate relationship with his engine. He has been very interested in my Mazda engine development, even to the point of asking if I would help him when it comes time to put a rotary engine into his airframe; but in the next conversation, he says that even with its warts, it is reliable, and that is very important when IFR at night over the great lakes.

Does this add up to you? I have a hard time accepting that any single internal combustion engine is reliable enough for night IFR over huge water. Dick Rutan, Ms Yeager, and Mike Melville and others have flown over the oceans for days at a time, as did Charles Lindberg.

To me, these are very brave people. Perhaps they do not understand what is going on inside that crankcase? Maybe it’s faith based on years of experience? If I ever do

get up the nerve to fly for hours beyond the reach of land or aid, then I will be certain to be flying a multi-engine jet.

Not a single Lycoming or Mazda.

There are failures of automobile engines in airplanes.

That makes sense when you consider that there has been very little development of the installation. What I mean is, that each install is a prototype with a new motor mount, intake/exhaust, cooling, fuel and electrical system. How can you compare that to an engine that has seen little change in fifty years? What really shocks us all is how often the old ones quit. That is usually from lack of fuel, broken valves, or wrist pins coming apart. My point, is that modern engines do hold together internally providing the supporting systems function.

The Wankel rotary has no valves or pistons to fail, so that I believe that the engine will continue to make power if it has spark, fuel, oil and proper cooling. On the other side of the same coin, both the spark and the fuel delivery are dependant on the electrical system. I expect that the battery will provide over one hour of flight if the alternator quits. My visual instrument scan includes the voltage gauge, and I am crafting an alert warning horn to get my attention if the oil pressure, water temps, or voltage goes out of limits.

George Graham Mazda Rx7ez N4449E www.bfn.org/~ca266 George offers a booklet for anyone interested in using a transmission for a PSRU. Please send $ 35 US check (or money order if not USA) to: George Graham 570 57th Ave W #196 Bradenton, Fl 34207

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son AZ area. So far the cooling system is working great. I have not seen over 210ºF Update: Lancair ES with Chevrolet Corvette LT -1 V-8 Engine on the water temperature and I’m still able to climb at full power to any John Harlow altitude without any oil or water temperature problems. jharlowjh@wmconnect.com (520)297-2367 The rebuilt airplane also flies straighter at cruise with very little rudder input. I originally had a bad right wing My story was first published in CONTACT! Magazine drop at stall (power on or off ) that I attributed to a differissue number 40, with updates in issues 53 and 66. ent original right and left wing build. The new wings seem to have cured that problem.

In issue No. 66 I wrote about my off-field experience, which was a result of bearing failure in my "Northwest I stayed with Northwest Aero for my new belt drive beAero" belt drive. At the time, I had 361 hours on my cause of changes they made in the new design. plane. I have since rebuilt the plane and now have 58 1. The top and bottom bearings now run in an oil bath hours on the rebuilt airplane. (vs. top bearings sealed and bottom greased) 2. The lower front bearing is in front of the lower sprocket instead of inside like the original design.

3. The belt adjustment is simpler with both bearings of the upper unit attached to the front plate instead of one bearing on the front and one on the back in the old design.

4. I also have a temperature sensor on the upper housing and the maximum temperature I have seen is 150ºF on shut down heat soak (which is just engine temperature soaking into the system).

The only problem I have with the belt drive so far is a slight weeping of oil out of the lower seal at shut down.

In rebuilding N350N I had to replace both wings (Lancair fast build), upper and lower Cowling, belt drive, engine mounts, propeller, nosecone, one main landing gear leg, all three wheel covers, and the front gear fork.

Two minor changes were incorporated in the rebuild. The new" Northwest Aero" belt drive lowered the prop centerline and extended the prop a few inches forward from the previous location, which caused me to have to lower the front of the cowl. Also I used the rear engine mounts from Northwest Aero instead of the Chevrolet mounts I had on the original completion.

I had a problem with the original wings because I used Hysol epoxy to close the wings. I found that auto fuel degraded the Hysol, leading to fuel leaks. On my new wings I was able to close them with the Jeffco epoxy that I built the plane with. The epoxy has a longer curing rate which gave me enough time to close the wings (with a lot of help). I have not had a fuel leak problem with this new system.

I am flying again and the plane seems to be stabilized as far as problems. It is still a great project!!!!

The other change was to the cooling system. I originally had a Camaro radiator behind the engine in front of the firewall that I always had a hard time getting air through. That radiator was destroyed in the accident and when I rebuilt, I put in a small Volkswagen radiator in the left hand cowl area beside the engine. I ducted one-half the left hand front opening into this radiator. This radiator is still in series with the lower radiator under the belly of the plane.

I’ve flown approximately 58 hours since the rebuild, all of which was in the Tuc-

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Continued from page 21 Maybe it was the fact that we had very little negative to say about the Sonex Ltd. products that lead this reader to believe that we were in the Monnett’s pocket. The fact is, we looked for the negative, in a serious way, but just couldn’t find any worth reporting. When I wrote my flight report I pulled no punches when I wrote how uncomfortable I was in the cockpit, but the plane flew really nice.

I also received a letter from a subscriber who informed me that he won’t be continuing his subscription, and wrote, “I guess what finally turned me off was the near cult-like interest in the Corvair engine.” Yes, we did an all Corvair issue, and yes I’m a fan of the engine. The reason for the all Corvair issue was to catch up on over a decade of ignoring the engine in the pages of CONTACT! and to do it in a way that did not spread the topic over several issues, which could lead one to believe that the agenda of CONTACT! was to spread “the word” of Corvair. The Corvair is a small, low power, somewhat antiquated engine (as compared to a lot of the modern computer controlled engines we showcase on a regular basis) that just doesn’t fit the needs of the majority of our subscribers; and I know this. Actually I don’t believe that any single engine does that anyhow. For those who can’t use the Corvair to power their project, I assumed they would find the articles as fascinating and interesting to read as those who are building smaller, slower aircraft find the larger V engine articles educational and entertaining to read. At any rate, we’d like to promise that CONTACT! will continue in the direction it was intended; it will not become a Corvair magazine, nor will we ever pander to kit manufacturers and become a 24 page advertisement for their products.

NEWSLETTER OF THE YEAR AWARD I was once under the impression that the EAA gave out an award every year for the “best” newsletter. I’ve since found out that I was partly correct. They give out an awards for EAA chapter newsletters, but ignore the type newsletter. As the editor of the Dragonfly newsletter for 3 years, doing a thankless volunteer job, I felt slighted. So I would like to begin this next subscription year with my eyes open for the unsung heroes who put together the newsletter for their type of experimental aircraft, and recognize them at the end of the year with a proper award. With that, I would like to ask that you contact the editor of your newsletter, and see if he (or she) wouldn’t mind adding me to his subscription list. I’m already getting several newsletters a month, and this is a great source of material for the pages of CONTACT! and a great way for me to keep up with what’s REALLY going on in experimental aviation.

SPACESHIPONE DOES IT AGAIN I’m sure you’ve already heard the news that Burt Rutan, Mike Melvill and Brian Binney have collected on the XPrize. I wish to extend our sincere congratulations to all involved.

While on the early morning drive to Mojave on that eventful day, to cover the story on the second of the two required attempts at the prize, I realized that I had pretty much photographed SpaceShipOne and the White Knight from every angle possible, just like every other photo journalist in the world. Then it occurred to me that there was one angle which no one had attempted to shoot before, that being from the departure end of the active runway 30, looking straight at the crafts as they leave the earth together. Long story short, I managed to get the one of a kind photo, and I offer that early morning photo below.

Pat Panzera

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