crankcase volume

[mickdale]

is it better to have more crankcase volume or does this not matter?

if using a 7mm packer and 115/116 rod i believe the crankcase volume is larger than std

if taking the packer away and using a piston with smaller crown height reduces effective volume - is this wise or to be avoided....

any thoughts greatly apprciated

regards
mick

[rosscla]

On a 70mm bore you'll add approximately 26cc to the total volume of barrel and crankcase simply by adding the packer.

Dependant on the stroke the volume will be larger by more or less than that at BDC.

Other variables such as the shape and size of the crank webs need to be taken into consideration when looking at primary compression.

I'm sure there was a fairly long thread on here somewhere discussing the pros and cons of high versus low primary compression set ups.

[mickdale]

thanks rosscla
60mm crank

will try and find the thread

[wack 63]

It will definatly use more petrol

[Darrell Taylor]

what exhaust you planning to use

[mickdale]

wow - i didnt think there would be a difference in fuel consumtion (thank god for diablo tanks)

darrell - pm sent