Heads upgrade worth it?
12-31-2006, 12:19 AM
#1
Heads upgrade worth it? I've got a set of perimeter bolt LS1 heads ported by CNC Cylinder Heads in Florida. Originally ported back in '99 with a few repairs due to broken valve springs, hydralock, etc. I don't have any details (refused by CNC multiple times) except valve sizes (2.02/1.57) and they were originally milled .030. Two other owners gave me the following combined information when they had their heads tested upon removal:
---snip---
Port Volumes (I/E): 229cc/86cc
Combustion Chamber Size (cc): 63cc
Flow Figures (I/E):
.100:
.200: 166/105
.300: 211/154
.400: 229/181
.500: 257/199
.550: 269/205
.600:
.650:
---snip---
I have no interest in spending $2K+ on a new set of heads at this time. Would any of the current 'budget' heads give me much better performance without a big financial hit? What are some realistic gains I should expect?
---snip---
Port Volumes (I/E): 229cc/86cc
Combustion Chamber Size (cc): 63cc
Flow Figures (I/E):
.100:
.200: 166/105
.300: 211/154
.400: 229/181
.500: 257/199
.550: 269/205
.600:
.650:
---snip---
I have no interest in spending $2K+ on a new set of heads at this time. Would any of the current 'budget' heads give me much better performance without a big financial hit? What are some realistic gains I should expect?
12-31-2006, 12:28 AM
#2
they aren't hogged out, 229cc's is pretty decent for a ported stock casting, and the flow numbers look pretty decent, about 20-30 cfm off on intake, and about 10cfm off on exhaust from the "budget" ported heads most sponsors advertise. I'm assuming they have some kind of valve job. The .200-.300 flow is great, and that tells me that even with a 229 runner, your low-mid torque and throttle response should be pretty solid. these are definately a step up from stockers, expect about 30rwhp increase on an M6 without any low-mid drop off.