I made several runs on the 60 FP today, but I couldn't find my gas modified carb so used a smaller throat perry. Basic conditions were: OS F plug, 20% Klotz oil, 13 X 6 Zinger prop. On each run I varied the amperage on the plug to see if it affected the timing. I saw little or no difference at full throttle, but it did make a difference when it was below 3000 rpm. Listed below are the numbers:

Omega 10% gasoline 10% Methanol 15%Methanol 20%Methanol 25%Methanol

9100 8200 8300 8400 8600 8900

Second series was with 5% acetone added to each blend

9200 8300 8400 8600 8800 9000

Only when the Methanol content was 20% or higher would the engine idle below 3000 rpm without the the glow plug heat, except on glow fuel. I ran the 20% and 25% mix with ethanol and the results were essentially the same except the needle adjustment was a little more sensitive than with Methanol.

I thought about trying some diethyl ether like the diesel engines use, but didn't have any available. Ether probably is a better ignitor than acetone would be.

One other thing. The OS has head shims installed to reduce some of the overheating problems I had running on glow fuel, so it is probably pretty close in compression ratio to an un-modified weedie.

Even though this would seem to indicate that Gasoline-Methanol mixtures can be used with Glow ignition, I think I'll stay with spark ignition. The principal reason is reliability and lower fuel mixing problems. Since I have several CH units which can be switched from plane to plane I have already made the necessary investment. One other point, I'm not sure about Glow plug life. The F plug was new out of the package to start. After the runs, It still glowed brightly, but definitely had the beginnings of carbon buildup. Probably as the result of cracking some of the -ene compounds in the gasoline.

Sorry about the table apperance, but my formatting efforts couldn't get the numbers to line up.

One thing I forgot to mention is that the engine had a distintly softer exhaust sound when running on the gasoline mixtures than on straight glow fuel. It also produced a much smokier exhaust, eaven at the leanest settings. This is probably due to a slower flame front with gasoline than Methanol.