Lowering C/R

[VEEDUBBED 0]

Right,nearly everyone knows that when you turbo/supercharge an engine the normally high Comp. ratio has to be lowerd in order to avoid detonation and holed pistons,lets say,for arguments sake that i don't want to use de-compressed pistons,2 head gaskits,bushed rods etc and that seeing as i have to remove the cyl. head anyway,why not modifiy the combustion chamber?.

When using 2 head gaskits the C/R is lowered to about 9.5/1 because the 2(G60-metal) gaskits combined are 3mm thick,how much metal needs to be milled out of the combustion chamber to obtain the same effect as using 2 gaskits?,has any 1 done this opposed to the other methods?,comments please.

[aquablueg60 0]

Well.... you can use a simple bit of maths to work out what difference is made by the extra head gasket!

Good old pi r squared x height gives you the volume of a cylinder. Hence you can work out the volume you need to remove.

You are very limited as to what you can remove from the combustion chamber becuse of where the valves seat. There is a little you can remove from around the sides but not enough to drop the compression ratio to a acceptable level.

[bix 0]

Just use low comp pistons...

[PhatVR6 0]

the beauty of LC pistons is that they are generally forged too, and thus bloody strong.

[Yandards 0]

the beauty of LC pistons is that they are generally forged too, and thus bloody strong.

 

and a bit lighter too I have found when comparing some of the pistons I have.

 

A good set of custom pistons is the way to go although you could try that C&C head company that were on here the other day for some advice.