Q-talk 13 - QUICKIE TIPS
- Category: Q-Talk Articles
- Published: Saturday, 31 December 1988 06:11
- Written by Jim Masal
- Hits: 1969
From J. P. Stroud, Satellite Beach, FL
I have about 390 hrs. on the tach on N406JP. A month ago I was flying in Central Florida and had just been enjoying life for about an hour. As I reduced the power to enter the pattern at River Ranch, the ol' Onan sounded as if one cylinder was missing at idle. I reapplied full power first to see what I had left and it ran fine. Again at idle, it missed. I elected to land and check it out rather than chance an hour's flight back to home drome (that's the only smart thing I had done in awhile as one will discover as he reads on).
The engine ran on only one cylinder on the ground. I looked at the engine and missed the obvious. I tried to start it and never got a pop. I decided the ignition was the problem since I couldn't see a spark on the grounded plugs. I replaced everything - still not a pop. Then I did the thing I should have done long before - I carefully looked at the engine with a critical eye and discovered a fine crack at the base of the right cylinder extending almost halfway around. That's when I made the second smart decision to remove and replace the engine before flying back home.
So mechanical failure caused the problem? No! Wrong again, sports fans. It seems I continued to miss the obvious. A couple loose bolts holding down the intake manifold had loosened enough to allow vibration to flatten one intake gasket allowing the mixture to lean greatly at idle. Luckily the rough idle caused me to land and eventually discover the cylinder crack which certainly would have caused the cylinder to come apart in flight. You can see I wasn't very smart. PREFLIGHT CAREFULLY!
To get home, I installed the Onan I bought from Norm Howell after he replaced it with the Rotax. Norm's old engine ran better than the one I had been flying for some time. There are lessons here folks on the old engine, and I will pass them on for what they're worth.
The engine had never really run as powerfully as any previous Onan I had been flying. The break-in was longer and the engine ran at higher temperatures than usual. Also the engine was "tighter" (the prop pulled through harder) AFTER flying, and the vibration level was somewhat higher at full power. All these are symptoms where the engine was "talking" to me and I failed to listen. Learn from my mistakes and happy flying.
ED. NOTE: Questions???? How many Onans have you flown, how many hours on each and why did you change each? Why was the break in longer on this one? I thought break-in was simply ground running for a specified number of hours that didn't vary.
Comment: Vibration implicated again! I've seen an intake manifold with safety wired mounting bolts. Extra effort, but apparently worthwhile.
From Dave Barth, CO
I have expanded on the report you printed in Q-TALK #11, adding more details. I would like interested QBAers to know it is available for a donation much the same as Miller, McCaman and Hawks did. Write 509 S. Cody St., Lakewood, CO 80226.
From Jerry Homsley, AR
My little Quickie is doing great. I overhauled the Onan recently when I couldn't restore compression any longer by lapping in the valves. Rebuild cost me $45. I rebuilt at 350 hr TT and it's purring like a kitten again.
Sure would like to be able to point the nose up on takeoff sometimes. I'm thinking real hard about a Rotax 503 conversion soon. Dave Barth has a great information packet on how he made the conversion.
Keep the presses rollin'.
From Dick Pettit, OH
I now have 115 hrs on the Onan and the airframe. It's a real pleasure to fly, but you must be alert at touchdown. I've timed my climb rate at 320-340 fpm for the first several thousand feet from a 700' ASL runway. Cruise is 108-100 mph at 3400 rpm hands off. My plane weighs 293 lbs. I've had so few problems with it. This fall at the annual, I replaced all the normal ignition parts - points, condenser, coil - although they showed no wear or cause for replacement. One coil wire needed a terminal repaired and the left exhaust valve needed a tiny adjustment. That was the total work required.
From Martin Burns, SCOTLAND
My Quickie G-BKSE has been grounded since last June for fitting a Rotax. I finally gave up on the Onan when, a year after rebuilding most of it, the left cylinder began overheating again in spite of all attempts I made to divert more cooling air in its direction. I am fitting the Rotax 447 under an Ed Miller cowling, which I shall modify to cut off the muffler (silencer to us British!) bulge. The silencer will be mounted transversely under the engine after the fashion of Gerry Wardell. I only hope that the changes in exhaust path length will not be as critical as some of your contributors suggest. Gerry, Ed Miller, and Brock McCaman have all been immensely helpful with long letters and photographs of their installations for which I am very grateful. I have developed a rather more complicated tubular steel engine mount than usual from which the engine is suspended on Lord vibration mounts. This is in order to leave enough space underneath for the muffler while still providing good vibration isolation. If it is successful I will send drawings to anyone interested later on (I'm interested. - ED).
The British Quickie-1 scene is unfortunately as small as ever. Paul Wright's Global powered machine came to grief after the engine stopped on him, but he is currently rebuilding it. G-BKFM has been sold but I don't know if it is flying yet. Tony Wahlberg is close to completion near Southampton, but he is contemplating a Rotax. There are a number of other kits in the country but I suspect they have stalled. I would be very pleased to be proven wrong.
ED. NOTE: Martin, DO NOT screw around with the exhaust path length on a 2-cycle engine or you will come to grief too. In order to eliminate 2 cycles from a 4-stroke engine, the exhaust pulses through the pipe length are carefully calculated to control the gas mixes in the cylinder. Change the character of the exhaust pulses by modifying pipe length or silencer and you will be buying new engine parts soon. It IS as critical as you've read.
From Gene Comer, IN
I received a note from Norm Howell ref. the Wardell 447 and muffler mods. Norm feels the muffler dimensions may have been altered to facilitate installation. L.E.A.F. maintenance people state that if the length is changed the likely result will cost lots of $$$$$$$$$.
ED. NOTE: Jim Prell's Suzuki has a transverse muffler, but he did not change the length when he changed the orientation. It's working just fine (but the pilot ain't).
From Richard Smith, LA
When I bought a set of Quickie plans recently, I did not realize they were drawn from kit assembly only. I acquired a destroyed Quickie from Jack Dempsey, but many of the metal parts are gone and most are not dimensioned in the plans. Any help from you guys will be very much appreciated. 110 Trojan Place, Lafayette, LA 70508.
ED. NOTE: I know the problem. I just bought a partial Q-2 kit with NO metal parts. Anybody know of a wrecked Q-2/200 with salvageable metal? Hmmm.....I know...I'm starting a museum, anyone have a donation?
From Harry Buskey
The Fulp/Buskey Quickie is flying almost every nice day. The more that I fly behind the Onan, the more I like and respect that engine. It's not the Onan's fault that someone put it into an airplane.
We recently performed a proctologic operation on the little darling. A pre-flight revealed a very large and ugly crack in the tail wheel spring. This crack was inboard of a splice that I had already made onto this rod a few years ago. Enough of this. Let's hear it for metal in this area! Here's how we did it:
I welded an 18" extension shaft onto a fly cutter with slightly greater diameter than the "rod" (I will use rod, spring and SOB interchangeably here). We cut the rod flush with the fuselage, then carefully marked and drilled the spring for the pilot in the cutter. Drill a little, cuss a little, resharpen the cutter, redrill the pilot hole, blow out dust, cuss some more, and so on and so on. After the first 8" or so, the center drilling became rather casual. But it can be done! After about 4 hours we had completely drilled the tailwheel spring out endways and stayed within 1/16" of center. It is important to stop drilling a calculated half-inch or so before the end of the spring so that the flox will be contained. Now it's a simple matter to flox in an aluminum tube (with the forward end sealed) and insert a steel tubing tailwheel spring with the attachment bolt well forward to reduce stress concentrations.
Karl Miller, 315 E. 14th St., Glencoe, MN 55336 (612) 864-4219
Quickie #388 (5589November) is flying!! As I stated in our visit at Oshkosh 88, the experience of the first flight was and remains one of the most thrilling, spiritual, fulfilling experiences of my lifetime to date. The retro conversion of the AED 440A Kawasaki is more than this type of aircraft needs. It's nice to be able to run at 4,000 RPM (60%) and get 100 MPH performance, but 6500 RPM's indicated gives me 150 MPH and the airspeed indicator starts shaking in direct proportion to my knees. For this reason, I feel I could get into flutter trouble over the VNE if I am not paying attention. It is great to get such a climb rate (850 at 70 MPH) at 6,000 RPM and 250 feet of runway to lift off. I am flying off of sod and have 20 hours at this writing. Landing is quite conventional with the exception of the time to bleed off in ground effect. Touchdowns are quite easy with slight forward pressure to keep from floating up after flair (round out). Ground handling has been just great since I reset the axles with a 20-foot 5/8ths pipe to get things on straight. The first taxi tests with the small wheels resulted in a broken wheel pant and change to Hegar fat tires with hydraulic brakes. A single lever is employed for braking; they work fine but are seldom used. When installing the fat tires, I moved the axles 8 inches forward (under the spar) from the old axle centers. I believe this has something to do with its docile tracking and ground stability. The AED configuration with the differential reduction is very smooth and quiet. I am getting a drumming noise at 6500 and just came in at last flight with a broken upper left motor mount bolt. This 3/8ths bolt sheared at the nut. It caused no real flight problems even though the engine moved left 6 inches from the firewall. I did notice that the ball was clear off to the right side and I was getting a higher head temp on the rear cylinder. I didn't know that I had a problem with the mount until I landed and made inspection. I believe with the horsepower increase that this causes a great deal more stress on the upper left bolt than would a 20 HP engine. For this reason I am going to add a fourth mount (1 at each bottom corner). I will also install 2 cables as additional insurance and connect to firewall separately. The drumming I referred to may have come from to tight motor mounts. I will report after 50 hours about the technical part of the reliability and specs after I have some more time on the aircraft. I would appreciate a lead on where to get a fourth, complete mount for the engine (the brackets and rubber).
I would prefer at this time to thank the designers, builders, and anyone connected to Quickie aircraft. I know at this state that I became over read and filled with negative thoughts after and during the building process. I walked around the craft for a year, trying to get the courage to fly it. This was self-inflicted fear brought on by years of absorbing information not relative to having plans and following the plans. We have never spoken to nor ever met Sheehan or any suppliers of Quickie parts. We bought the kit from a previous owner and followed the plans until completion. The only real change was in the selection of the powerplant. This plus the Q-TALK builder's support can result in an aircraft that does what the design says it should do. I am absolutely astonished at how easy this airplane is to fly and maintain. It is especially amazing that this can be accomplished by a Minnesota dirt farmer with a pliers, a monkey wrench and an understanding wife. Show me a guy that badmouths a Quickie and I'll show you a guy who's going to be stuck in the world of conventional experiences. My advice to builders in process....finish it!! You can't imagine the thrill, the rewards that are in store for you.
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