Keep 317s or Not?
Keep 317s or Not? I might have a few extra dollars after i sell the 408w out of my mustang and was planning on running 317s with my setup. Ill do a fast run down and you can tell me what you think. Aiming for 700 HP on med/lower boost.. and 1000HP Fullout through t56.
lq4 shortblock
truck manifolds
317 Heads
Comp Turbo CT5 with a 80mm GT45 compressor wheel, triple ball bearing aluminum center section and a 79mm inconel turbine wheel. 1.15 AR divided ceramic coated turbine housing
Probe 4.00" 3.622" Stroke 2618 -16cc Forged Pistons
Eagle Forged 6.125" H-Beam Rods
Vic Jr manifold with rails
Low profile elbow
90MM wilson TB
78# Delphi Injectors
Aeromotive A1000 pump with filter and boost regulator
Comp Cam DUR @0.50 INT 226 EXH 236 Lobe SEP 114.0 Valve lift INT .584 EXH .601
ls2 timing chain
trickflow pushrods
ls7 lifters
patriot gold springs
Melling oil pump
Harland Sharp 1.7 rockers
50MM Tial BOV
Precision 46MM Wastegate
Snow stage 2 meth kit w/progressive controller
AEM wideband
AEM TruBoost controller
Unknown 3" inlet 4" thick intercooler
lq4 shortblock
truck manifolds
317 Heads
Comp Turbo CT5 with a 80mm GT45 compressor wheel, triple ball bearing aluminum center section and a 79mm inconel turbine wheel. 1.15 AR divided ceramic coated turbine housing
Probe 4.00" 3.622" Stroke 2618 -16cc Forged Pistons
Eagle Forged 6.125" H-Beam Rods
Vic Jr manifold with rails
Low profile elbow
90MM wilson TB
78# Delphi Injectors
Aeromotive A1000 pump with filter and boost regulator
Comp Cam DUR @0.50 INT 226 EXH 236 Lobe SEP 114.0 Valve lift INT .584 EXH .601
ls2 timing chain
trickflow pushrods
ls7 lifters
patriot gold springs
Melling oil pump
Harland Sharp 1.7 rockers
50MM Tial BOV
Precision 46MM Wastegate
Snow stage 2 meth kit w/progressive controller
AEM wideband
AEM TruBoost controller
Unknown 3" inlet 4" thick intercooler
TECH Resident
Joined: Jan 2011
Posts: 934
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From: Tulsa
If your aiming for 1Khp, get rid of them. They can make it and make power but to be safe get and aftermarket head with a thick deck. And why that Turbo? There are cheaper awesome quality Turbos out there.
I have that same turbo with an 84mm turbine. It's a bad mother. Im running 15lbs with it through 317's & LS9 head gaskets. Just bought a 2.5 bar map to turn it up some. At 15lbs you should make over 800 wheel through a T56.
Yea the turbo i have is a bad bitch and it wont lag, great turbo and the guys that sell it stand behind their products.. I was just curious is there a step up from 317s sorta inexpensive heads? If i were to get another set...
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There is a few companies out there now that make a great aftermarket head. I think afr is one of the first so they would be your best bet for finding a cheaper head as you can find an older one. Not that it gets much cheaper going used but better then brand new. But money is money!
I got my 235cc's for 1800 from the for sale section here. have yet to start the engine but they look great!
GL
I got my 235cc's for 1800 from the for sale section here. have yet to start the engine but they look great!
GL
Seems like a lot of mixed opinions. 1 question I have maybe someone knows since I'm not very technical with compression. Right now with my setup I was told it should be around 8:8:1 compression with 317. Would a set of afr heads bump it up or lower it ??
The cc of the head and the head gasket will determine whether the compression ratio will stay the same or change. So naturally if you match the cc and keep the same type gasket your compression will stay the same. The higher numerical number the cc head (from whatever the 317's are) will lower your compression and visa versa... This is referring to static compression.
the 317 heads are 72cc from GM. and 72 is the largest number that i have seen for heads. Not that there isnt anything bigger but id guess they are out of the ordinary. The ones that I bought are 72cc as cast then a little porting to smooth it out so maybe a few more cc there. It took a bit of looking to find a set for 72 as most people use the piston to lower cc and then stick with a mid 60's cc head.
The 8.8 you believe you are currently running is well into the safe area so if you got something smaller it wouldn't be so bad.
GL
The 8.8 you believe you are currently running is well into the safe area so if you got something smaller it wouldn't be so bad.
GL
the 317 heads are 72cc from GM. and 72 is the largest number that i have seen for heads. Not that there isnt anything bigger but id guess they are out of the ordinary. The ones that I bought are 72cc as cast then a little porting to smooth it out so maybe a few more cc there. It took a bit of looking to find a set for 72 as most people use the piston to lower cc and then stick with a mid 60's cc head.
The 8.8 you believe you are currently running is well into the safe area so if you got something smaller it wouldn't be so bad.
GL
The 8.8 you believe you are currently running is well into the safe area so if you got something smaller it wouldn't be so bad.
GL
This is easy. If you can afford an aftermarket casting, buy heads. If you cannot, use 243s or 317s with LS9 gaskets. I'm making 1k flywheel through 317s, but I still wish I had thicker heads so I could push it a bit.
Yea thats what Im affraid of, getting to my limit then wanting more. The engine im building could hold more. But also thinking maybe get an extra 50-100 HP by putting better head on.. I was planning on LS9 gaskets for sure, with aftermarket head like AFR people still using those gaskets or do you nedd other gaskets for some reason?
Well, you got all that dough in the motor, and its turbo, etc etc....and you wanna slap on some thin deck el cheapo heads on it? not me. the PRC 237's are the way I went considering they were spec'd for the larger motors, and they are a few hundred less than the AFR, but flow just as well, and the deck is thick as hell. Over 3/4 in some areas according to what I have read. Not cheap, but reasonable.
http://texas-speed.com/p-1171-prc-23...der-heads.aspx
nice *** heads too. not a ton of info on them in comparison to afr, but hey, everyone has afr and tf just about, and even if that is for a reason, I like to be a guinea pig from time to time.
http://texas-speed.com/p-1171-prc-23...der-heads.aspx
nice *** heads too. not a ton of info on them in comparison to afr, but hey, everyone has afr and tf just about, and even if that is for a reason, I like to be a guinea pig from time to time.
Last edited by I8UR4RD; Jun 4, 2012 at 05:57 PM.
I'm bolting on PRC215s soon, got them in the garage. After I dyno I'll provide some more insight. I'm anticipating 75ish HP just from the swap and who knows what with more boost.