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Engine basics => Engine set up tips => Topic started by: James Holford on August 11, 2018, 01:23:58 PM
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Looking for a prop size to start with on a Super Tigre .23. 8x4?8x5?9x4?
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I used both 9-4 and 9-6 on mine and the engine ran perfectly.
The final size will be determined by the engine/plane setup.
My last one was on a Jr Flite Streak with the 9-6.
Bob Z.
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Biggest problem right now is the run.
Changed plugs numerous times.. finally OS #8 gets it going. Had to open it alot to get it to actually run.
Running at 12600rpm. Try to needle in to rich'n it up but stutters n dies any time it gets in the 11000 range.
Now Im thinking its maybe fuel?
Running powermaster 10/22. Probably not enough caster for it.
RSM snubnose 3oz tank Uniflow. Fuel is actually vibrating out the uniflow vent. The vent is a little as all the vents as the tank comes. May need to cut it down a bit.
Jim Lee Venturi as is the ST type NVA he sells...
APC 9x4 on it now
I dont know what else the problem can be.
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If youve got a Bladder or a Pressure nipple . . . .
Free Flight Power some runem open intake , No Insert .
Check for hairline cracks in the case around the spray bar .
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Blow through a piece of fuel toob , through spaybar , adjusting needle . if your not deaf .
Intake IN it should do the same . Or blow in a big tube over the intake , maybe under water , checking for leaks .
MUFFLER Series II 23's have a CRESENT shaped lower exhaust edge in the cyliner sleeve . Staight Port earlier oones loose half the sauce , muffled .
Broken skirt the go even better . :-X
See Sceptre Flight injun tests .
8 x 6 or 9x4 for me . Hadem in the 262 Maiden flight , fair howl , got two more/ other , Now .
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Biggest problem right now is the run.
Changed plugs numerous times.. finally OS #8 gets it going. Had to open it alot to get it to actually run.
Running at 12600rpm. Try to needle in to rich'n it up but stutters n dies any time it gets in the 11000 range.
Now Im thinking its maybe fuel?
Running powermaster 10/22. Probably not enough caster for it.
RSM snubnose 3oz tank Uniflow. Fuel is actually vibrating out the uniflow vent. The vent is a little as all the vents as the tank comes. May need to cut it down a bit.
Jim Lee Venturi as is the ST type NVA he sells...
APC 9x4 on it now
I dont know what else the problem can be.
That fuel should be OK, it's possible that the venturi is too large. I would probably start with a 9-4 myself, but don't expect miracles. It's a very powerful engine for its era, but it's only average compared to now.
If it is misfiring, spitting back, quitting unexpectedly, it may also be that, and I hate to say it, it is *overcompressed*, and maybe it needs a new stock head gasket, or .005-.008 more clearance. A lot of the high-performance baffle-piston engines had the compression and/or head clearance jacked way up, as high as it could safely go, to try to get more performance, or to run on FAI fuel. A possibility would be to switch to 5% and see if it gets better, if so, probably overcompressed.
Note that this doesn't mean that if .005" is better, .050" is ten times better. If .005-.008 doesn't fix it, this is probably not the problem. People are far to quick to jump to throwing head gaskets in there by reflex, but if you do have the head too tight, small changes would probably fix it, and nothing else will.
Brett
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Venturi is .143
I may end up putting the engine to the side for another day.
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Venturi is .143
I may end up putting the engine to the side for another day.
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I've successfully run 145 in .28's that were pretty fast!
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I've successfully run 145 in .28's that were pretty fast!
Yea.. for the plane I wanted it in it may be too much for OTS.
Ill drop a .25LA in it.
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