Before I do any engine work I have to make sure I can find a good source for racing fuel. One local shop wanted $12 a gallon for VP110!

I would like to go to a 14:1 (stock bore or 105.5), what is the lowest octane level I can run?

I noticed that different companies quote octane levels using different methods, R+M/2, MON, and RON. Ex. VP110 MON: 107, RON 113, R+M/2 = 110. I believe the method at the pump is R+M/2. So when I read claims that you need a minimum of 100 octane are there referring to R+M/2 method? Can someone set me straight on this.

Besides octane ratting, there is the choice of leaded or unleaded. Pros and Cons?

Last question, anyone know anything about F&L Racing Fuels?

 

From what I have read the 14:1 is designed to run on 110 and I assume the are referring to 110 using the R+M/2 method.

Leaded or unleaded?

Someone has to have an opinion

 

I go by motor octane #

VP makes leaded fuels designed for 4-stroke, It burns better and runs cooler IMO.For 14:1 compression try c-14, If you are drag raceing it may be a bit more safe to run 114 for high reving passes. You can get away with a good brand fuel that is a true110 octane though.