Ok so I'm rebuilding my 4k and have 5k pistons (8cc volume) pistons. Just wondering if any one can point me in the right direction to what my compression will be. Head is a ke70 4k head. Hope this is enough info. Thanks in advance

wait wtf?

 

are you trying to put 5k pistons in a 4k? or a 4k head on a 5k block?

He is trying to make a 1500cc 4k.

ah i see, *awaits altezzaclub reply*

lol! thankyou Evan!

 

"Flat top" or "O-dish" 5K pistons have about a 5cc dish in them. Your stock 4K head combustion chamber is about 31cc, gasket about 7.5cc. Motor is 80x73 now isn't it, = 367cc.

 

So you have (367+7.5+5+31) going into (5+7.5+31) or 410.5:43.5 or 9.4:1. Not high because the dish in the piston is 15% of the head volume.

 

A real flat top piston would be (367+7.5+31) into (31+7.5) or 405.5:38.5 = 10.5 to one!

 

Measure a piston dish for volume and make sure!

Thanks guys I'll measure the piston