Its gettin close!
Dec 13, 2005 | 08:03 AM
#12
I'd rune the LS1 heads and put your money toward a set of forged pistons. You coiuld still choose your CR with the valve relief size but end up with a better quench area. That means a better combustion and less detonation.
Dec 13, 2005 | 08:25 AM
#13
Originally Posted by BigTex
I'd rune the LS1 heads and put your money toward a set of forged pistons. You coiuld still choose your CR with the valve relief size but end up with a better quench area. That means a better combustion and less detonation.
LS1 block bored to 3.905
Deck milled .006" to get a good surface
Mahle -16cc Forged Pistons
Compstar Connecting Rods
Stock Crank 3.622
Arp Main studs
The LS1 heads
2.02in./1.57ex.
Ported/Polished
Chamber polished
Milled a total .015"
It should be around 66c
8.9-1 CR
317 heads... Stock
Valves Stock
No porting
Stock valve Springs
Has not be milled
Should be 71cc
8.4-1 CR
Dec 13, 2005 | 09:02 AM
#16
Originally Posted by BigTex
I agree, I think 8.4 is too low.
What head gasket are you going to use (diameter and thickness)? How far does your piston extend above the deck?
What head gasket are you going to use (diameter and thickness)? How far does your piston extend above the deck?
Dec 13, 2005 | 11:07 AM
#17
TECH Fanatic
Joined: Sep 2004
Posts: 1,288
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From: Somewhere between Auburn, AL and Columbus, GA
Im not an expert on this stuff, but i dont see why 8.9 wouldnt be just fine for 12-15 lbs. I know that people w/lq9s in the SSs run 8-9 lbs all of the time and that engine is over 10:1 compression with stock internals. I know my brother was going to run something close to that on his ss with his gt67 kit that he has laying around. Im not sure why he hasnt put it on. Just throw some meth on top of it when your at the track. BTW, besides the combustion chamber size diff, how do the 317 heads flow compared to stock ls1 heads?
, but I cant have my truck down 
Dec 13, 2005 | 11:18 AM
#19
Originally Posted by BeefTip
Im not an expert on this stuff, but i dont see why 8.9 wouldnt be just fine for 12-15 lbs. I know that people w/lq9s in the SSs run 8-9 lbs all of the time and that engine is over 10:1 compression with stock internals. I know my brother was going to run something close to that on his ss with his gt67 kit that he has laying around. Im not sure why he hasnt put it on. Just throw some meth on top of it when your at the track. BTW, besides the combustion chamber size diff, how do the 317 heads flow compared to stock ls1 heads?
The 317 heads would flow better if they had bigger valves and where ported. The exhaust side would flow alot beter. Im just ready to get this thing running and the LS1 heads are ready to go where the 317 will need about $350 to fix them right(Bigger valves and machine work) and another 2 weeks down time. It wouldnt matter if I had the money but christmas is coming up so I want have the money till the first of year.
Last edited by Yellowsierra; Dec 13, 2005 at 11:32 AM.
Dec 13, 2005 | 01:19 PM
#20
TECH Fanatic
Joined: Sep 2004
Posts: 1,288
Likes: 0
From: Somewhere between Auburn, AL and Columbus, GA
hell, through the ls1 heads on there and just keep the 317s. Whenever you get the cash, port and polish the 317s and the valve work and put them on later next year if you are not happy with the ls1 heads. It might be a pain to change that stuff out later, but you might be totally happy with the ls1 heads and you will be on the road in a few days. Im willing those 5.7 heads will do the job just fine. BTW, what type of numbers and times are you shooting for? I dont see why you wouldnt be around 600rwhp if not more at 15lbs.
