Octane/Compression on a 300 ??

[StrokerOMCSS]

i am running 145 psi compression on a 300, would 93 octane be good for this engine, i had #5 go down, i think water went under the oring but i am not 100% sure and before i rebuild the engine i want to know atleast i changed something to make sure we dont repeat the same problem, so we are going to check all the enjectors / cdms/ and i am having a set of heads cut to 135 psi, like a standard 300x motor, so any info or ideas i would really like to hear thanks Stroker300SS

[03bignasty]

I would just buy a set of 62cc Simon heads from Eric. You know they're cut right and they look great. Give him a call.

[Double Rigged]

Check with Eric Simon. He has many heads. We were told by him that you do not want to run over 135 on 93 pump gas. I would also recommend installing pyrometers on the engine. This way you can see the exhaust temp. If it goes over 1275 or 1300 you are in trouble.

[y2kstang]

Not trying to be a fly in anyone's ointment but simply gauging octane requirement by cranking compression is not the way to go. The only way to really tell which octane would perform best without going overboard would be time on a dyno. Anyway, cranking compression is a decent place to get a very general idea of what you should run but a 135 compression motor with timing in it will require more octane than 93. If you can put the motor on a dyno first then that is what I would suggest. Otherwise just run higher octane than you need if you can't get the dyno to pinpoint it.

[The Big Al]

[quote=Double Rigged]Check with Eric Simon. quote]

That would be the best advice!!!!!!

call Simmon

http://www.simonmotorsports.com/index.html





.

[THE HOGG]

And If You Get Simon Heads You Can Use The Stock O-rings and Change Compression At Will. They Have Inter-changeable Combustion Chambers. Not Tomention They Look Awesome:d

[StrokerOMCSS]

thanks for the info, we have found that the orings did dont seal off and we sucked in water in the block, as for my cut heads we were with in .001 of standard oring deepth and width, i have been told by several people 145 is on the line and just as many that 145 is fine on 93 but i am not going to take chances and i will have the new set at 130-135, thanks Stroker300SS

[03bignasty]

I bet they were teflon o rings. I heard of a few problems with them Johnny.