learn something today

[courchaine]

One of my teacher is really involved in performance :

-Atv racing in the early mid 90 (sponsored by suzuki)
-Superbike racing in the mid 90 (sponsored by suzuki)
-Snowmobile racing so damn fast 140mph on 1/4 miles
-he build racing engine for a lot of racer around here

Well i was talking to him today because i buy my racing gas from him and he just told me that a pump gas can be used on a compression as high a 12,7 :1 he told that there is no problem on running pump gas on a 12:1 compression ratio. Well i was quite surprise but i can't argue with him because he just know so good what he is talking about......so i just wanted to share this with those of you that were wondering like me


Max

 

[yamarider]

Well technically, you could probably run a 12:1 on 87 or some strong alcoholic beverages. Will it run well? Not necessarily. I know at least one guy on here, I think it's ds, runs a 12:1 and I remember him saying that it doesn't run very well on straight pump gas.

There's more to it than just the compression though. Other design factors affect it as well. For example, a bombardier ds250 has 10.6:1 compression stock, and the owners manual recommends 87. My warrior is 10.25:1, I put 87 in it and it runs like hell.

 

[jasonp]

I agree there with yamarider.. . just because someone race's doesn't mean they know anything about engines. Usally the engine builder and rider have always been seprate. I say after building this engine... it's really not all about just replacing a part, it's about all the details that come with it. As far as engines running higher compression then others well that's just a design factor there.

 

[warriorcliff77]

Like what yamarider is getting at is there is a relation between the following: Octane VS Compression ratio, VS Timing and Combustion temperature. So yes it verywell may run on pump gas, but he may have the timing retarded to compensate for the lower octane fuel, thus delaying when the plug ignites the mixture.