Olds Edelbrock O4B?

[maxwedge]

I have read a few times now in Hot Boat that the older Edelbrock O4B is the manifold to have for a lower RPM Olds lake motor. I'm just wondering what makes it different or better than the newer Performer manifold?...and are we talking just a couple HP or is it a dramatic difference? Timminator, care to elaborate? Anyone?

[maxwedge]

Bump? Nobody has a guess even?

[malcolm]

The O4B is pretty much just an aluminum version of a stock manifold. I wouldn't think they would outperform a Performer. :)
I don't think it will clear an HEI cap either, if that's in your plans.

[TIMINATOR]

I'm back from the river. The O4B is a 60s-70s era dual plane manafold, it has large runners and a medium sized plenum. In that era there weren't very good street tires, so making low end torque wasn't an issue. The single plane manafolds were in their infancy then, so mixture problems were common as was the lack of applications for non-popular engines. The Performer was designed for torque and economy, it has small diameter runners and a small plenum. Its good to3800 rpm or so or if you cant find anything else. The performer series also has a constant cross sectional area in the runners. Good for torque but not for rpm or high flow. Air flow in a runner will be higher in a slightly tapering configuration, the old manafolds had that. Had they made the plenums smaller and the runners tapered it would have been better yet. We have come so far on airflow tech, but Vic won't spend the $$$ for the 455 guys. He told me at the PRI show years ago that no-one runs Olds motors and there was no money in it. Yet he makes an intake for a HOLDEN, and Olds heads........ You can port a Performer, but there is little gain for the cash. I have been beating on Holley to make a big Olds dual plane and Eagle and Scat for an Olds stock replacement crank. And the BIGGIE!!! Cast steel crank with the journal size for BBChevy rods, and my favorite, a stroker that fits BBChevy rods! CALL THESE PEOPLE AND TELL THEM!!!!! At 4500 rpm the HP difference is about 20-40 depending on the other components. Thats only 1-2 mph, but we WANT it! TIMINATOR

[maxwedge]

So in your opinion how would the Performer with an Edelbrock 750 stack up against the stock manifold and Q-jet on an otherwise pretty much stock motor with logs? Obviously there is a large weight savings over the cast iron if nothing else right?

[El Prosecutor]

I'd like more input on this topic if anybody knows anything.
In Timinator's famous Practical Olds article it says the O4B is the best, but doesn't elaborate.