Dished or flat tops
Thread Starter
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Dished or flat tops Planning a 347 forged shortblock.
I do not want high CR, however I would like big flow LQ9 stage II heads.
So my question is: Would it be better to have?
1- 59 CC heads with dish pistons (Diamonds)
Or
2- Flat tops with 67 CC Heads
I plan to shoot up to 150 N20, max 200 if need be.
Also this would be with a high lift cam, possibly a G5x3
I do not want high CR, however I would like big flow LQ9 stage II heads.
So my question is: Would it be better to have?
1- 59 CC heads with dish pistons (Diamonds)
Or
2- Flat tops with 67 CC Heads
I plan to shoot up to 150 N20, max 200 if need be.
Also this would be with a high lift cam, possibly a G5x3
Thread Starter
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Originally Posted by jrp
what compression range are you looking for. i have diamond domed pistons myself 
. i assume with either dished or domed you'll run vavle reliefs?
. i assume with either dished or domed you'll run vavle reliefs?Do you think the Dished would be less prawn to detonation for Nitrous? assuming CC's are fully polished and free of hot spots.
TECH Resident
Joined: Jan 2003
Posts: 855
Likes: 0
From: AUSTIN TX
I would say use which ever one (combustion chamber) that flows the best. Traditionally that would be the slightly larger chamber as it would unshroud the valve better, but you could check with the head guy and most likely find out. If he does not know exactly, have him flow test both with a tube to simulate your stock bore.
