87 octane

[wireweld]

My engine is 10.5 to 1 cr and the gas we have around here is 87 octane. Can i use this gas safely or is there a way to raise the octane of this gas. I can get 91 but I have to drive almost 50 miles.

 

[ramcharger]

The only way to know for sure is to try it. Basically it comes down to cranking pressure and whether or not any quench was built in to it. Also, just because a manufacturer says that their engine is 10.5:1 or 10.5:1 pistons were installed, that doesn't mean that the true measured compression ratio is as indicated.

The camshaft selected for the build has a tremendous effect on cranking compression too. Gearing and torque converter stall/slip will have an effect, tire height, distributor type and settings, carb settings, altitude, etc., etc. and list goes on and on.

We will need much more information but it will still be an educated guess.

 

[Poppabear]

I do not use any gas with ethanol in it, I always buy from Shell or any station that does not use it.