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  2. Revmaster to o-200 conversion

Re: Revmaster to o-200 conversion

Gary McKirdy
 

I have some experience with this problem.

It is possible to increase the effect of the existing sparrow strainers first.

On a Q235 the sparrow strainers were made adjustable to find the sweet spot necessary for trimmed flight. It turned out to be with a good few degrees of extra negative angle of attack from plans for the 0200!

That shows you can add a bit without risking stalling them out.

Just make sure they have a solid glass seat for the pinch pivot bolt and washers which need to be tightened after each ground adjustment, you don't want them vibrating loose and altering the stick feel at an inopportune moment.

If yours are in the prop wake then switching prop rotation will have changed everything. I would advise moving the sparrow strainers out of the propeller wake altogether before experimenting or power changes will cause a trim feedback loop and not necessarily a good one.

Hope that helps.

Gary

On Sat, Aug 22, 2015 at 12:18 AM, john.hartley1@... [Q-LIST] <Q-LIST@...> wrote:
 

Update:
After 14 hours on the new engine, I was experimenting lower power than I expected and an excessive amount of oil coming from the crankcase breather. I found plans for and made a contraption that measures crankcase pressure. Mine was excessively high, leading me to believe I was experiencing some piston blowby.
Since I recently jettisoned my second wife and am now single ($), I bought 8 new Superior Millennium cylinders (4 for the Tri-Q200 and 4 for my Cessna 150). The 150's cylinders were shipped to my house and the Quickie's were sent to LYCON for some tweaking. LYCON installed 10:1 NFS pistons and port, polished and flow matched the cylinders.
When all 8 cylinders made it home (couple weeks turn around from LYCON) I was able to compare the stock ones to LYCON's. These gentlemen do an extremely nice job.
All 8 are installed on their respective aircraft. The master solenoid on the Cessna went bad and is on order, so I haven't flown it yet. I have flown the Q2, however, and it has come to life. It picked up 190 static rpm (2550 vs 2360) turning the same 60x70 Sterba prop and 20 mph indicated (170 vs 150). The engine isn't broken-in so I haven't pushed it too hard yet.
In the essence of experimenting/tinkering, I pulled the engine off of the plane today to prep it for its next upgrade - SDS EM5 4F fuel injection and digital ignition. Ross from SDS has been a big help so far and needed only 3 days to build my system (after we hammered out all of the details). The system is supposed to be here Monday.
While I've the plane torn down again, I'm going to tackle some of the things that've bugged me for a while. On one of which, I'd appreciate some input. At high speeds, the nose tucks down; the faster the speed, the more the tuck. At 170mph, it's an uncomfortable amount. At 200mph, it's as much as I'm willing to put up with. The thought of removing the canard to increase the incidence (it's the LS1 and was originally installed with 0°) is uncomforting but not insurmountable. I'm thinking that the other approaches would be to increase the size of the sparrow strainers or install the t-tail.
Thoughts?

John
Tri-Q:114 hours
Tri-Q200: 16 hours
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