I think he is refering to the valves at the head itself as the bottleneck.

Fortunately, I dont claim to be an expert at gases, or anything else.

MikeR

 

I'm just a nerd with thick glasses! When I hit the lottery and buy all these cool mods you guys have including these Needwings manifolds. Whats next? Is there hidden power just waiting to be discovered by removing the cylinder heads ? Porting them out,3 angle oversized seat with sodium filled valves. Is there enough meat in these cylinder heads without hitting a water jacket? Hope we can all be friends on this fourm and just take it out on each other at the stageing lanes. Don

 

Hey squirrel, Look up the photo of the M/B3.2 with its heads removed it will freak you out as to how thick the cylinder walls are. Like it has been said before these things are built like tanks.
Mike

 

Thanks....I'll check it out..

 

Math is a funny thing; there is always repeatable logic in the numbers themselves, but only if you are using constant variables. Unfortunately in the real world, we also have to deal with things like temperature, altitude, and therefore air density and so on. I urge you to go grab one of the stock manifolds and look up its skirt; that hole is very tight. If you are wondering how you can increase power without increasing the flow of the head itself (that's what I interpreted), you have to realize that the stock heads are capable of out-flowing the stock manifolds. The opening in the restricted part of the manifold is probably only as big as ONE of the three intake ports on the head. I don't believe the stock manifolds are capable of supplying all of the air the cylinders are capable of consuming when running upgraded pulleys and air intakes.