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Engine basics => Engine set up tips => Topic started by: frank mccune on August 17, 2021, 09:22:32 AM
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Hi All:
Does this engine have spi?
Does it have a baffle on top of the piston?
How many ball bearings does it have?
Tia,
Frank McCune
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Hi.
The G20/19 (like many other S.T.) has undergone many changes over the years. The first edition had the head made of casting, the piston had a baffle and two rings, the shaft was supported by a rear ball bearing and a front plane bushing. The various modifications resulted in an engine with a machined head, a flat piston without a ring and two ball bearings. I have no information regarding S.P.I. but I would not rule it out especially in the first versions, the big brother G20/23 originally had two small open corners at the base of the exhaust port with the piston at the TDC.
Massimo
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Hello Massimo:
Thank you for taking the time to reply.
I have never owned a G20/.19 but my friend flies one. Of course it is a very fine running engine!
I have run many G20/.23 engines and they run very well if one omits a muffler! With a muffler and spi, the power is reduced about.40 percent! They are a fun sport engine.
Stay well,
Frank McCune
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Back in about 1949, I owned a Super Tigre G-19. It was .29 cuin with a sand-cast crankcase. It's main feature was an exhaust stack on each side. I think it had ball bearings, but not sure. I believe it was intended as a racing engine, although I used it for free flight with a 10 inch prop. So it never got overr 9K RPM.
It was just another engine to me, and I later sold it for next to nothing. I now realize my mistake!