I am currently rebuilding a 69 olds 455 and are the final stages. I put high compression pistons (part#L2323) 30 over stock size and edelbrock cam (part#2152). The heads are pretty much all stock exept sure seat springs and hardend seats for unleaded fuel. The main question I have is will this combo be able to run 93 pump gas?

Thanks
Dustin

 

You should be fine. What were your goals?

 

Should be fine. Depending on deck clearance and head gasket volume your probably around 9.25 to one compression. The Edelbrock cam is pretty girly-man, defiantly tame in a 455. What is the rest of the combination?

 

That's awesome!
I agree, my friend had the same combo, disappointing for him. But if that's what you're looking for then o.k., have at it, your call.

 

Well this is my first rebuild and wasnt planing on anything real crazy, more of a weekend warrior lol. I bought the pistons with the motor and the guy gave me chevy parts such as valves, valve springs, oil pan (idiot). Any suggetions or advice on parts im all ears guy's thanks

 

Depending on your desired hp those pistons are fine, add some clearance though. Compression with those pistons and an 80cc head will be right about 9.50-9.75:1, good for a cast iron headed street application.

An Edelbrock Performer, headers, 2.07/1.68 valves and the right cam will get you to 400hp and and the better part of 500lbft of torque.
I'll grind the cam for you if you want or help give you a few choices. I'm sure others will contribute as well.

 

I do have a offenhauser intake, msd ignition, headers and such. I was told by the machinest the valves were pretty big stock. What cam might have you went with?

 

comp cam roller rockers also

 

Depending on your gear, probably an Erson TQ40 or JB100. Works well with stock or slightly upgraded valvetrain and heads.

Specs are 228/235 on either a 110(TQ40) or a 112(JB100), lift is .504 on both.

Let me know if anything in your combo changes.

 

What did you decide on the pistons. I am rebuilding my 64 cutlass with the 330 and I am not sure which pistons to order. It had the high compression pistons but with todays gas what kind of problem would I have with using the low compression pistons?

 

My engine that i have it also had come with the high compression pistons they were the speed pro part #L2323 and man let me tell ya what a wake up call lol. No lack of power, I just run 93 pump gas and there is no knocking anywhere not even when i get on it a lil. The pistons arnt everything either tho depends on your heads to so. Hope this helps

Dustin

 

What does the more compression ratio do to the engine? I know high octane is needed but does it give you more HP/torque?

 

It's the best way to increase torque and hp form idle all the way up. Plus it gives you more room for different cam choices.
But you can go too high as well, especially on todays fuel. Gotta be careful.

 

So what would be your limit of ratio with a 91 to 94 octane level fuel. What about those octane boosters, do they work?

 

Keep it at or below 10:1 MAXIMUM! Mine is higher and detonation on today's gas is a problem, I live with it daily. You can build a good motor at 9.5:1 or 9.75:1. Going higher creates issues. Remember, back when cars had higher comp. ratios, there was 105 octane gas...when comp ratios lowered, so did the octane ratings in gas.

 

So 10 is the limit when it comes to 94 octane?