Mixing race gas with pump gas...

[Krooser]

Let's say your running a 12-1 compression motor. You are buying 110 octane race gas. Some guys blend this 110 with 91-93 pump gas.

What do YOU do… run straight race gas or blend it with pump gas? Is 110 too much octane for a 12-1 engine?

[keeks]

I'm not sure you can run fuel that is too much octane. But don't mess around the other way. Too low and bad things are gonna happen.

[wisdirtfan]

Too much octane is no good either. More octane means slower burn so if you don't have the squeeze to burn it all it will carbon up the chamber and valves. How much octane depends on compression cam timing and general cam specs because things like overlap will reduce cylinder pressure.

[stock car driver]

110 is good for 12-1, I would run it straight.

[jsf74]

whats worth more your expensive race motor or "saving $2 a gallon by mixing your gas and creating a failure.

[dereksehi]

I wouldn't mix racing fuel and pump gas I have seen several burned and broken pistons that have been running on mixed fuels its bad news.

[Drake Racing]

On a 12 to 1 engine, don't mix it, something around 10 to 1 and you will b ok.
I mixed 110 and 91 octane Amoco ultimate 50/50 in an IMCA stock car 360
and had no problems, but mine was closer to 10 to 1 than 10.5 to one. If
you mix, be sure to use same fuel from reputable station each time to avoid
any inconsistencies.
Curt Drake
IMCA Late Model #55x
IMCA

[Krooser]

Both the fuel dealers I've talked to and some refiners online info have said you can gain more power with the correct octane… too much can cost horsepower.

Thanks for the input.

[el paso mod 19]

I've mixed fuel for 2 1/2 seasons now. Where I buy my fuel, the owner asked why I ran the 110 straight. He said with my 12-1 motor to mix it half and half, but, mix with regular gas not the high octane. He said the way the gas companies raise the octane level for premium gas does not mix well with race gas. I mixed it 3 to 2 at first and was surprised that my motor was actually more responsive and ran cooler. So, then I went ahead and mixed it half and half and motor ran cooler still and motor really came alive. He also was telling me that one time he was rototilling his garden and ran out of gas and only had 110 at his house so put it in-motor wouldn't even run. So I assume there is such a thing as too much octane.

[Krooser]

28 blends… could they make this any more confusing? Looks like the WISSOTA rulebook…
http://www.vpracingfuels.com/vp-racing-fuels.html

[Krooser]

Thanks El Paso… pretty much the same info I heard last week from the two dealers I talked to...

[roundboy]

I run strait 110 in a 12.5 to 1, 377 all steel motor, but i have also ran short on lawn mower gas before and dumped in a gallon of 110 to finish the yard, cant say if the mower did or did not run any better, but it sure smelled great finishing the job!!!

[Hurst390]

You will get lots of different opinions but how did you end up with 12-1? with a domed piston and big chambers I would run 110 straight...Some of my engines are 12-1 with a flat top and small chambered heads and I can run pump 93...but I do mix a gallon or 2 of 110 if available and have for years with no problems...