100 Octane LL AV Gas

[JRSully]

I use AvGas quite a bit for the high compression BB. It is relatively cheaper compared to race gas, lasts forever (no ethanol breakdown). What I find is that when it is very warm out, it can idle a bit wonky (I have a stock 11:1 L78, all timing in at 3k). A splash of 93 can help there as you did. I also find that if you are running a stock Holley, it needs to be squeaky clean. I regularly pull the idle screws on the metering block and blow the idle circuits out with an air blast (Thx to Eric Jackson for that tip), change the brass filters regularly as well. With all that, my engine responds pretty well with AvGas

[WILMASBOYL78]

Originally Posted by JRSully

I use AvGas quite a bit for the high compression BB. It is relatively cheaper compared to race gas, lasts forever (no ethanol breakdown). What I find is that when it is very warm out, it can idle a bit wonky (I have a stock 11:1 L78, all timing in at 3k). A splash of 93 can help there as you did. I also find that if you are running a stock Holley, it needs to be squeaky clean. I regularly pull the idle screws on the metering block and blow the idle circuits out with an air blast (Thx to Eric Jackson for that tip), change the brass filters regularly as well. With all that, my engine responds pretty well with AvGas

I started using this stuff about 15 years ago in snowmobiles...had to increase the jet sizes in both sleds. AV gas is designed to not absorb moisture...water in an airplane fuel system will hasten the use of parachutes.

Blending it with some 93 non-ethanol high test is a good idea...or if you feel wealthy a little high octane race gas.

Our L78 cars seem to run pretty good with it...of course all big block cars go faster on the flat roads of Long Island