explain head cc`s

dwhiskie said:

I believe the 58,60,61 ect is the chamber size but dont understand,is the smaller the chamber = more compression or does this have anything to do with the compression? Im lookink to get a new set of heads but want to understand this before I do thanks for any input

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the smaller the chamber the higher the compression will be. the reason is that the air has to compress into a smaller area ie. 58cc. make the chamber bigger ie 64cc and the air has more room so the compression is less. hope this helps.

The CCs are a measure of the amount of cubic centimeters of volume you can hold in a head's combustion chamber... Higher CC numbers will yield lower compression. You calculate compression roughly by the volume in a cylinder after a piston has reached top dead center compared to the volume with the piston at bottom dead center. Lower CC numbers will give you a higher compression ratio. Volume of the piston's displacement, the gap around the piston down to the rings, and head gasket thickness all play a part in calculating compression precisely...

For instance, a dished piston yields a higher compressed volume after the piston reaches top dead center, so therefore, it yields a lower compression ratio. Dome pistons yield a higher compression ratio for the opposite reason...

Basically it is space that air can be compressed into. If you have a specific volume of air you compress on every compression stroke then x amount of power is your result. However if you increase even more air (oxygen) in the same amount of given space, then more fuel will be delivered and by law, you will have a bigger explosion which creates more power. By downsizing the combustion chamber size, this is in a round-about way a simulation of this effect. You have in reality the same amount of oxygen but in a smaller amount of space, the comustion chamber pressure right before ignition (or at TDC) will actually be greater than before because it is in a tighter space (aka, higher compression). Compression is exactly what the word sounds like it is, the whole process is trying to cram as much air into a given amount of space. It is a little complicated to explain perfectly but if you can picture it in your head, it is just one of those things you get sometimes. There are limitations to how low you can go and too much compression can harm your engine. Basically it depends what you are using the engine for, but I would suggest to not exceed 10:1 final compression because pump gas might not support it.

Hope this helps a bit.

Is it possible to run t/f twisterd wedge heads with flat top pistons?? that sounds like it has p/v clearance problems written all over it