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What octane should i run?


Guest Wicked ATV

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Guest WICKED ATV

im saving up for a 4mill cheetah cub but in the mean time i have a freshly rebuilt 420 BB ported with a trinity cool head with 20cc domes. I also have a adjustable ignition plate what degree should i have it set on and what gas should i be running 93pump or 110 or 1/2 and 1/2. thanks.

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Compression has more to do with the need for race gas than timing, unless you're talking about a TON of timing, which you're not.

 

The only way to know for sure if you need race gas is to use a quality compression tester and get a reading.

 

Here's a BASELINE, so your milage may vary.

Up to 150PSI should be ok for 92 or higher PUMP gas.

 

150 to 165 a mix of 50/50

 

165 and up...race gas.

 

Now...timing throws this off just a little.

So...this again, is just a BASELINE. If your motor starts knocking or pinging, you need to up the ante on octane...

 

If it were me on the engine you have, I'd run 8 degrees of timing and straight 110 race gas to be safe!!

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