What performance potential with my heads?
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
What performance potential with my heads?
Checked the casting number on the heads that I have on my crate engine in the yellow '68.
They are late model Vette heads: casting number 10088113
Part number: 12556463
Type: Corvette Design for 350 HO service engine
Casting number: 10088113
Material: Aluminum
Intake Runner Volume: 163
Combustion Chamber Volume: 58
Valves I: 1.94" E: 1.50"
Angled Plugs
The intake runner volume seems kinds low.. so I wonder what the performance potential of those heads? Would they have enough potential to get 400 HP out of them? I read that those heads are more modern design with D-shaped exhaust ports etc...
They are late model Vette heads: casting number 10088113
Part number: 12556463
Type: Corvette Design for 350 HO service engine
Casting number: 10088113
Material: Aluminum
Intake Runner Volume: 163
Combustion Chamber Volume: 58
Valves I: 1.94" E: 1.50"
Angled Plugs
The intake runner volume seems kinds low.. so I wonder what the performance potential of those heads? Would they have enough potential to get 400 HP out of them? I read that those heads are more modern design with D-shaped exhaust ports etc...
Team Owner
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From: central America
St. Jude Donor '08-'09
People get 400 horsepower out of double hump heads (165 cc intake volume) so I imagine that its not impossible. Sound like a good set of heads if it came on the ZZ4.
trw
trw
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From: Millington Illinois
St. Jude Donor '08-'09
Thread Starter
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by Star79
If you buy bigger heads hold onto the ZZ4-ish ones I'll buy em off you next time I visit Fla 
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Racer
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From: Creswell OR
Those heads came on the 88-91 L-98 Corvettes also.I'm reading John Lingenfelters book,and he likes these heads.He says with some "intelligent" porting you can get excellent flow from them.With the 58cc chambers,I wonder what your compression ratio is?
Melting Slicks
Joined: Apr 2004
Posts: 2,083
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From: Montreal Qc.
Originally Posted by GrandSportC3
That might not be an option.. Those heads have 58cc chambers.. Most aftermarket PERFORMANCE heads have 64 or larger chambers.. That would drop the compression ratio and that's not something that I want to do... Therefore, I'll try to get more power from my current heads...
Racer
Joined: Feb 2005
Posts: 301
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From: Little Italy MI
[QUOTE=Gordonm]Didn't I hear you say you were going to leave this one pretty much alone and just drive it. 
That did not last to long
That did not last to long![ Its hard to settle for 300 ponies when you've been launching 600.
Last edited by 77TSi-meez; Apr 8, 2006 at 01:37 PM.
Thread Starter
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
[QUOTE=77TSi-meez]
not looking to get the performance anywhere close to 600 on the yellow car.. 400 would be good enough 
Originally Posted by Gordonm
Didn't I hear you say you were going to leave this one pretty much alone and just drive it. That did not last to long
Melting Slicks
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From: Mid West
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I think those are the same ones that came on my ZZ4. I did some light porting (removed material around valve guide, smoothed out the walls and machining marks, etc.) and replaced the stock valves with Manley Race FLow valves. I'm currently making 328 rwhp, 355 rwtq with these heads and a decent cam. I can't quote net HP, because I'm not sure of the driveline losses. It's good for a high 12 sec. 1/4 mile though .
.
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by Jason Staley
I think those are the same ones that came on my ZZ4. I did some light porting (removed material around valve guide, smoothed out the walls and machining marks, etc.) and replaced the stock valves with Manley Race FLow valves. I'm currently making 328 rwhp, 355 rwtq with these heads and a decent cam. I can't quote net HP, because I'm not sure of the driveline losses. It's good for a high 12 sec. 1/4 mile though .
.
Thread Starter
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by BLACKHORSEVET
Lingenfelter claims with proper port work on these heads you can generate up to 250 cfm of intake flow at .500-inch valve lift.
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There went the budget!!
Lingenfelter ain't cheap!
JIM
Lingenfelter ain't cheap!
JIM
Thread Starter
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by 427Hotrod
There went the budget!!
Lingenfelter ain't cheap!
JIM
Lingenfelter ain't cheap!
JIM
Pro
Joined: Sep 2002
Posts: 690
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From: near Memphis TN
ZZ4/L98 heads. On my combination it's been good enough for a best of 13.05 1/4 mile. The heads were purchased by and ported by a previous owner and put on a tired engine, then migrated to a new engine. Dave Emanel in one of his books is also a fan: "In stock form the Corvette aluminum heads has good airflow characteristics which are sufficient to support the needs of an engine producing a maximum of 330 HP. Properly ported, however, these heads are suitable for 400+ HP engines."
Valve size is limited to 2.0/1.6.
Valve size is limited to 2.0/1.6.