Hi All

Would anyone know what the volume in cc's in the dish on a 4k dished piston.

 

Thinking about hitting the dyno, with a 4k dished pistons and closed chamber mid port on a 3k, to see if it makes more power than our current 3k flat top with bigport head.

 

Just need to check the CR ratio on the midport combo is OK prior to building one.

 

Cheers

Andy

D's? Would be around 20cc's for the sake of some calculations.

D's? Would be around 20cc's for the sake of some calculations.

 

..and 6cc for the "o" dish.

 

These are 5K pistons we are talking I assume, 4Ks are flat as I recall.

4K-u had d dish pistons and close chamber head.

Must have been a 4ku I saw a mid port on. I'm guessing say 20cc in the piston and 6 cc in the head, would be about 10 to 1 ?? on a 3k

what head are you mid porting, a 4ku head or 3kc head. Not sure if it is the same for both heads. my 4k dished head is much much shallower than a standard 4k head. id measure the difference but the dished head is at my parents house lol.

I've got one closed chamber head havn't cc'd its at my engine builder, its for a 3k, rules don't allow me to machine the pistons, so I was thinking, dished pistions to bring the CR down.

oh ok, i had a 3k bigport head on my 4k dished pistons, and i think it may have brought it down to far, as it was doughy to drive, would be good for a turbo setup though, which i may still do.