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QuickTalk 9 - QUICKIE HINTS - (PART TWO)

/This is the second in a two-part report on modifications and alternatives to the Onan engine for the Quickie. -Ed./


From Advanced Engine Design, Inc. (P.O. Box 589, Flint, MI 48501):

AED operational objectives are in developing alternative high performance powerplants and related support equipment and we recognize a real need for this in the sport aviation field. We are enthused about our ability to apply some new approaches in the areas of engines and drive train products.

We got into the Quickie application through Lanny Rundell of Grass Roots Aviation. Lanny is a Quickie dealer in Louisiana who took an interest in our engines at the 1982 Lakeland Sun 'n Fun Fly-In and felt that our product might solve some of the problems associated with the Onan engine installation. Lanny outlined what he felt were problems with the propulsion system and its related effect on the aircraft. We entered into a development program in July 1982, and the first test flight was in March 1983.

The design criteria or our retrofit project concentrated on several key items: performance, reliability, vibration, weight, noise, maintenance and retrofit capability. We call this project the "Super Quickie" Retrofit Module. This kit is being offered with three inter-changeable powerplants:

1. 82-100 HP Spitfire liquid-cooled 44LC-B, which is a custom built, hand crafted, high performance engine.

2. 72 HP Kawasaki TC440-A liquid-cooled engine.

3. 52 HP Kawasaki TA440-B air-cooled engine.

All three of these powerplants are 440cc vertical-inline twin, 2-cycle engines. The necessary engine speed reduction is accomplished by a planetary gear reduction of 2.1:1 ratio. The transmission is rated up to 125 HP at 10,000 RPM. Starting is done either by electric or manual recoil in the cockpit.

Due to the inherent design of two cycle engines, there are only three moving parts. No valves, valve train, camshafts, oil pump, ignition points and oil level to maintain and adjust. A tune-up for these engines consists of replacing the spark plug. A major overhaul can be performed by most people in approximately four hours at home with a minimum of tools. AED also offers a service department.

Fuel requirements are quite diverse: regular or no-lead auto fuel as well as 80/86 and 100 octane aviation gasoline. The carburetor for all three is a Mikuni 32mm Slide Valve type. With respect to oil mixing, the ratio is 24:1 and is automatically controlled by a variable ratio pump. (No hand mixing of oil and fuel.)

The initial test flight by Lanny Rundell was very encouraging. With the test plane at 542 lbs. gross on a 57-degree day, takeoff was 550'. Climbout was at 72 mph and 1800 FPM. This was even with a plane of so-so construction and no cowling! At 20% power, the test plane averaged 135-140 MPH in cruise and used 1.5 GPH of fuel. It is expected that top speed will be in the range of 175-200 MPH at full power with the 72 HP Kawasaki.

We are prepared to offer a complete package for the Quickie homebuilder. AED's retrofit will include engine, transmission, support systems, spinner, choice of Yrral prop, instruments (tach, EGT, water temp, Hobbs, etc.), cowling and engine sub-frame assembly. The installation requires a four-point engine mount as opposed to the current three provided by the Onan. Also, extra fuselage-to-firewall structural tapes will be required.

Pricing on the kits is as follows: TA440-B (basic) $2195; TA440-B (complete) $2795; TC440-A (basic) $2995; TC440-A (complete) $3495; 440 LC-B quoted on request. Basic kits exclude prop, cowl and spinner. Those interested in the Super Quickie Kit should contact our factory for additional information. (313) 742-0602. Ask for Lance Wheeler or David Shortt.

Although this retrofit module has been subjected to many hours of intensive abuse and prolonged high speed operation, it must now be put to the time proven test of actual flight time. Thousands of flight hours are necessary for a complete evolutionary cycle with any new concept. Therefore, it is our intention to work very closely with our clients as we develop and market the Super Quickie Kit.


/Ed. Note: QBA members should understand that the above mod is still being tested. As of this writing, only 37 hours of actual flight time have been completed. Advanced Engine Design is currently building several Quickies for flight test and demonstration purposes. We have been told that those wishing to buy ahead of this time would be given special factory support./



/The following article is taken from a report by Ray Anderson #236 (written by Harold Little, #147). These gentlemen have graciously consented to the following edited reprint. They ask that any questions be forwarded to the QBA offices in order to be addressed at one time./

It should be noted from the outset that Quickie Aircraft Corporation's selection of the Onan B-48 engine was an excellent powerplant choice. Within the overall design constraints and specifications developed by QAC, the Onan engine met the various compromises required in this type of aircraft and its mission. Among those specifications were included such parameters as availability, reliability and low cost.

To arrive at a satisfactory engine type, QAC conducted an extensive engine availability survey, and procured for testing those types of engines that met the minimum specifications. The engine that apparently met all of QAC's parameters was the Onan B-43 (16 HP) engine, which was installed in N77Q for flight-testing. Also under evaluation was the Onan B-48 (18 HP) engine, which weighed slightly more than the B-43. This engine was also flight-tested and the performance results were compared with the B-43. QAC froze the design of the Quickie and offered it to the public with the B-48 engine. With builder weights averaging 15% more than the factory prototype, even the B-48 offered little horsepower in excess. QAC then began an engine modification program to extract additional power from the B-48. The retrofit kit offered to builders included milled heads (approximately .050"-.060") and a modified carburetor to achieve 22.5 horsepower, plus a Kevlar engine mount to suppress vibration.

Subsequent to the installation of these modifications by the builders, the head stud nuts would not maintain the proper torque. This happened to Quickie N1V (S/N 236) built by Ray Anderson of Shelbyville, Tennessee after he switched to the higher horsepower conversion. The plane had 20 hours of flight time prior to this, while still operating on the original 18 HP engine.

Upon converting to the QAC high horsepower heads, Ray monitored the engine operating parameters and engine condition very closely during the initial flight hours. Additional thrust was obtained, as more power was generated, but operating temperatures also increased. However, Ray noted that the head nuts would loosen with each flight, a much more serious problem than the higher temperatures. There is an incredibly sharp pressure spike when the engine knocks, as it does with the QAC 22.5 HP heads, each time the cylinder fires. The pressure is over the valves, which do not yield, so that all the force is transmitted through the head to the head studs. The original Onan studs stretch and eventually the block threads begin to yield. As the nuts are continually re-torqued, the studs will eventually pull the engine aluminum threads out of the block.

In the spring of 1982, Onan graphite composition head gaskets were tested in conjunction with the high horsepower QAC conversion. In a combination of ground and flight-testing in excess of ten hours, two improvements were noted. First, the cylinder head temperature was reduced noticeably. Second, the head nuts retained their torque for a longer period than originally obtained with the QAC approved gasket with anti-seize compound. As the nuts were still not holding adequately for safe cross-country flight, an additional test was implemented.

The test consisted of installing Helicoils in the block deck together with the graphite composition head gaskets. A brief engine run determined no improvement in the head nut holding torque, so special-order long Helicoils were obtained. These inserts went the full depth of the block deck holes, affording greater stud holding power. An additional brief engine run was made, with no improvements in the holding torque. SAE Grade 8 full-length studs were then installed, the engine run, and again, no improvement. The Helicoils, which had been inserted one plus turn below the block deck as required by the instructions, were noted to be rising. It was obvious that the block was yielding, allowing the inserts to rise.

An evaluation of the situation revealed specific clues as to the nature of the problem. Since the head temperature had decreased, the loosening of the head was not heat related. Further, the nuts were only loosening on the studs surrounding the spark plug in the area over the valves. A careful examination was then made of three heads - a new Onan B-48G-GA018 (18 HP) head, a new Onan B-48G-GA020 (20 HP) head and a QAC modified high horsepower head.

The interchangeable Onan 18 HP and 20 HP heads had dramatically different combustion chambers. In the B-48 engine series, the piston is flush with the block deck at top dead center, so that all combustion, at TDC, takes place over the valves and the piston within the head. The Onan heads had a substantial deck clearance area between the head volumes over the valves and over the piston. Even though the total head volume is less in the 20 HP head, for the higher compression ratio, there is a large enough area within the head to allow a smooth combustion flame front transit over the entire block deck, valve faces and piston crown in both the Onan 18 HP and 20 HP heads. To enhance smooth, knock-free combustion, the 20 HP head has had the spark plug repositioned to approximately the center of the head volume. By contrast, the 18 HP head has the plug at one end of the head volume, requiring the flame front to travel in a line all across the valves, deck and piston.

The QAC modified head has an extremely small area in the head between the valve area and the piston area. Upon firing at 23 degrees advance, the flame front is essentially throttled at the head restriction, with a very rapidly increasing compression wave front impinging on the opposite side of the restriction. This effectively caused a knock over the deck and valve area with each firing, as confirmed by the extrusion of the Helicoils from the block. This was additionally confirmed by the fact that no excessive temperatures were involved, only high pressures.

The Onan B-48G-GA020 (20HP) heads were installed in N1V, in conjunction with the graphite composite gaskets. The results were most gratifying. Once again, the CHT decreased, this time to the point where it would not exceed 390 degrees corrected (except for extended ground run periods). The same result was confirmed by moving the CHT thermocouple to the head studs adjacent to the exhaust valve and test running the engine.

There are two reasons for the reduced CHT, with the obvious one being that the graphite gasket has a superior heat transfer ability. This allows substantial heat transfer across the head-deck joint, so that the cooler block can dissipate some of the peak combustion head heat load. The second reason for the lower CHT is in the design of the head itself. When Onan upgraded the B-48 engine to 20 HP, not only was the combustion chamber changed to provide knock-free operation at the higher compression ratio, but the fin area was also increased to better dissipate the additional BTU's extracted from the 20 HP combustion. As the QAC high horsepower modified head was the 18 HP Onan, there was considerably less fin area to handle the higher heat load that was being generated. The Onan B-46G-GA020 (20 HP) engine is designed for use with regular leaded or unleaded gasoline, so that conversion to the Onan 20 HP heads and graphite gaskets does not require premium fuel. Premium fuel may actually be a liability, from the CHT standpoint, as the higher combustion temperature of premium fuel will only generate additional heat to be dissipated in not generate any additional power.

The most rewarding finding was that the head stud nuts lost essentially no torque after five engine thermal cycles to seat the gasket. After many hours of both ground and flight-testing with no appreciable torque loss, it was decided to deliberately reduce the nut torque in one foot-pound increments until the head gasket failed. The test was to release the torque on the cool head, then torque up to the test setting and run the engine with the service propeller and no upper cowling for fifteen minutes at 3600 RPM, reducing power to maintain 390 degrees correct CHT. The torque was reduced to less than two foot-pounds on the three nuts bracketing the valve area of the head and to less than five foot-pounds on the remaining nuts with no gasket failure.

The success of the head/gasket test program has produced an engine with excellent cross-country serviceability, to be used with great confidence. Should Onan further upgrade the B-48G-GA0 engine to still higher horsepower that will also be tested. For now, Quickie N1V has been transformed into the aircraft that is described in the brochure.



You can order a PDF or printed copy of QuickTalk #9 by using the Q-talk Back Issue Order Page.