ST G15 and G20/15

Did Peter Chinn or someone else ever write any articles on how these two engines performed?

I'm sure that "the Aeromodeller" would have published reports on these. I'll have a look in my copies from the early to mid 60's next time I find them. I did check out Tony Enmore's engine test web page at:

Engine tests: http://www.the.elmores.btinternet.co.uk/engine_tests/_cat001.html

But most of it doesn't seem to be there anymore! Must have pruned it to save space. Perhaps if you email him directly he may have them.
Try: [email protected]

According to Ron's Model Engineering site, the G15 was tested by Peter Chinn as follows:
Diesel . April 1969 Aeromodeller
Glow . March 1975 Aero...

The G20 was the subject of many tests by many writers.

See the list at http://modelenginenews.org/index.html

Hope yo u get the ones you're after.

Greg

From a user of both types, I can tell you that whilst the G15 is a nice, smooth, easy starting motor, the G20 is more powerfull, especially with the big venturi running on pressure. I alway find the G20 a bit of a s0d to start though !!

I really only liked two of my six engines. The other four were an ongoing struggle to operate in a satisfactory manner.

One dilema was the RPM. You had to rev them high to get a smooth run. But the main bearing fell apart at high RPM and I could not find an upgrade that fit. Once the bearing failed, you needed another whole engine, which was available from Cox.
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G21/35's also changed a lot, but the good/bad mix was more like 8/2 on the plus side.
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G20/15's were much more popular in Europe, but seldom seen in the United States. I assume because World Engines decided to import the G15.

I have happier memories of both motors. A friend of mine flew FAI speed when it first appeared as an event during the early/mid 1960's and I bought in turn from him, his G20 and then G15 as he upgraded. Used the motors in .15 combat models. Both were very happy on a Tornado 7x4 with about 10% nitro on crankcase pressure. No bearing problems, but metric replacements were readilly available here in Oz. I still have the G15 somewhere in bits, but I also now have a .15 G20/15D (diesel) which is a real powerhouse.

Is it the Diesel or Glow versions you are interested in ?

I was reffering to Diesels in my reply above.

Thinking about it, did they make a G15 Glow motor ?

G15RV = FAI Team Race
G20/15D = Combat

The G20-15 glow has a saddle-shaped head; the G15 more like a hemi head. The X-15 head sits on top of the cylinder and is a hemi type. George Aldrich in his 1967 Aeromodeller Annual write up on speed shows how to make a Cox TD 15 head into a head button for an ST.

If I were going to race G20-15 glows, I would get a different head made which would, I think, make them run with the G15's. We ran G15's in Midwest Limited Goodyear until they all broke and the event died. Our stuff was 100 MPH and reliable one hit start and restart. Fastest time was 7:14. We ran our limiteds in regular Goodyear and were 19th in the nation in 1970 something. At that time a low 7+ 10 mile time would place in most local contests.

Oh, the good old days.

Late in the program, ST brought out an RV conversion kit for the G.15 (might also have fit the G.20?), which I tried without success. I don't know if they just didn't get it right, or if the leakage and mechanical drag just didn't pay off for .15's. In the late '60's, I was working toward F2C, and tried a G.20 Diesel with a Cox .049 venturi, but I didn't find much magic with starting it. An Eta Elite Mk. II was quite another thing...sweet engine. Steve

Bigiron

I have one of those X-15's. A real powerhouse of an engine, and only run a few times.

Unfortunatly for Mr. Garofali, the engine hit the market at the same time as the Nelson.