The biggest but not the only. Things such as fuel type, temperature, cam timing, ignition timing, piston shape, combustion chamber shape, head material, and a few more, dictate whether an engine will detonate.

Well..............this is difficult to answer because of the above answer; but; all in all, (and some will dissagree) I think about 11 to 1 is about it. I think that will be a good average number if there is such a thing.

Naaaaaaa, like you, I like to help people. BTW, I really respect your posts, and I have read a lot of them. You always give good advice, and you have no axe to grind on any brand. There few people that post as good as advice as you. In other words, I would hate to meet you at the track, because people like you know your stuff, and I don't need the competition!!!
I was at the track this weekend and I could not get my drivers car to run right (fuel curve problems). There was a car there that flat cooked off the trailer, and I had to think, is his crew chief maddog56??[img]i/expressions/face-icon-small-happy.gif[/img] You just stay away from California!!!! [img]i/expressions/face-icon-small-wink.gif[/img] Ha ha ha ha........................

 

Some times the search don't always help.......they are new people that get on here every day. I like to see what they say also.

 

LOL....Thank you very much for the compliments doc. I too appreciate your posts and the wealth of knowledge that you have shared here with others. And no, it wasnt me that tuned that car you saw last weekend, Fuel problems always get me flustered[img]i/expressions/face-icon-small-smile.gif[/img][img]i/expressions/face-icon-small-wink.gif[/img]

 

I use 110 octain racing fuel.

 

hey, currently i run 87 pump gas..the comp is like 7.8 to 1 i believe..4 stroke.i hheard that if i ran 91 octane the engine would blow due to excessive heat from lower compression[img]i/expressions/face-icon-small-confused.gif[/img]i was wondering if i could use 91 octane instead, my machine is all stock?

 

You can run premium, but as was said, you would not gain any power, and may lose some. With that low of a comp ratio then you really dont need anything higher than regular pump gas. Just kind of throwing your money out the window.

 

In my 2005 300ex it states on the specs sticker on my frame to run 91 octane or higher. I've been running 87 since I got it around August last year. I'm currently trying 93 octane right now and I haven't rode it enoufht lately to see if it makes a difference. My buddy ran night test in his 2006 arctic cat 250 and claimed it started easier and ran better. I have yet to find out. All in all just run what's recommend for you machine because that's what its made for. If its recommended you use a higher grade its probably to reduce the chance knocking in your engine.

 

The only function of octane that I'm aware of is as an anti-knock additive. Most engines other than the high-performance ones run fine with lower octane like 87. I've heard that higher octane gives you worse gas mileage, the reason being that the more octane you have the less actual gasoline in the mixture. I don't know for sure but would think it shouldn't be much difference.

 

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