cylinder head question!!!
Thread Starter
Drifting
Joined: May 2001
Posts: 1,392
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From: Wabash,IN
CI 7-8-9-10 Veteran
St. Jude Donor '08
cylinder head question!!!
what would i gain by swapping out jus my heads off my 98 corvette
i dont want a cam jus yet but was curious if jus changing them with some ported ones like say (afr, patriots,etc) would make a difference or not Thanks JAY
i dont want a cam jus yet but was curious if jus changing them with some ported ones like say (afr, patriots,etc) would make a difference or not Thanks JAY
Drifting
Joined: Nov 2005
Posts: 1,406
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From: Dallas Tx
Enough of a difference to justify the expense if you plan on doing nothing else to the car?
HELL NO.
I'd only do them if you plan to do a cam, headers, and/or forced induction also sooner or later.
Shane
HELL NO.
I'd only do them if you plan to do a cam, headers, and/or forced induction also sooner or later.
Shane
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
There have been two tests I know of now with the AFR 205 head and a stock cam. Both tests picked up almost 40 HP. I think the heads with Crane 1.8 rockers might put you to 50 HP increase as the rockers will give you additional lift and also additional duration at the valve itself.
I think the key thing to consider here would be keeping the intake port volume small (cross sectional area small) or you will lose your bottom end and then when the head intake velocity catches up you will be out of cam.
I think the key thing to consider here would be keeping the intake port volume small (cross sectional area small) or you will lose your bottom end and then when the head intake velocity catches up you will be out of cam.
Former Vendor
Joined: Mar 2004
Posts: 1,518
Likes: 7
From: Valencia CA
Originally Posted by vettenuts
There have been two tests I know of now with the AFR 205 head and a stock cam. Both tests picked up almost 40 HP. I think the heads with Crane 1.8 rockers might put you to 50 HP increase as the rockers will give you additional lift and also additional duration at the valve itself.
I think the key thing to consider here would be keeping the intake port volume small (cross sectional area small) or you will lose your bottom end and then when the head intake velocity catches up you will be out of cam.
I think the key thing to consider here would be keeping the intake port volume small (cross sectional area small) or you will lose your bottom end and then when the head intake velocity catches up you will be out of cam.
We also conducted our own test during the development of the product and saw a 37 HP advantage with NO other changes (stock cam). The bigger news than that, however, was the power past peak....by 6500 RPM's the stock headed motor lost around 30-40 HP (from its already lower peak) where the AFR 205 headed combination was only down 9 HP from it's higher peak. Almost a 60 HP advantage there with the engine hanging on much longer. Keep in mind that is usable power as you would certainly shift the new combo around 6600 RPM's so your average gain in HP is actually higher than the 35-40 peak to peak numbers might lead you to believe.
Also, low RPM TQ and HP, throttle response, AND fuel economy are all significantly improved. Barring the obvious lightening of your wallet, its a win-win situation every way you slice it. Its simply a much more efficient, better designed cylinder head flowing 70 more CFM thru the SAME size hole (almost the same....205 cc's versus 201).
Hope this helps...
Tony M.
Melting Slicks
Joined: Sep 2005
Posts: 2,625
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From: Rhode Island
Originally Posted by mdhmi
At a minimum toss in a Z06 (LS6) cam if you do heads. Doing a cam at the same time as a head swap is really not much more expensive.
Mark
Mark
