[BigBlockBabe]

I was doing some reading on 429/460 heads and about open and closed chambers.

Can some explain WTF this in reference, too? What's the difference if you look at the heads, and is one better over the other in relation to performance?

Thanks!

[woodz428]

Open chamber heads ( and on the 460 they aren't as noticably different as they are on the 351C) were a creation (other than say a Hemi which although open isn't in the same context as a wedge) of the emmisions era. The quench of the closed chamber head gives more low end torque and acts to reduce detonation but was found (prior to FI and hotter ignitions) to generate unburned hydrocarbons which is what they were working to reduce at the time. The open chambers theoretically were supposed to flow better ( somewhat) but gives up some of the bottom end. Now I think if you look at most aftermarket heads they have a closed chamber that helps tumble the fuel air to reduce the hydrocarbons without losing the bottom end.Most of these benefits have come from the developement of a clear combustion chamber test lab that allows observation of the flame front as well as computer aided analysis and design.