Re: indy x heads on 318-390 build
[Re: roadrunnerreds]
#1674625
09/21/14 06:30 PM
09/21/14 06:30 PM
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Joined: Jan 2003
Posts: 5,895
Florida
Locomotion
master
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master
Joined: Jan 2003
Posts: 5,895
Florida
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Just like the 1.88" vs 2.02" in the same OEM head, I don't believe it would be a lot of difference, everything else being equal. But the more radical you go, the bigger the difference will be.
I've run low 11.20's @ around 117 with those LAX heads with no porting, 360, 10.5 compression, .474" cam and footbraking a 904 @ 3,540+ lbs! Both as cast, but blueprinted and a good valve job, I figure they are at least 2 tenths faster than comparable OEM 1.88" heads. Ports are bigger and flow better, plus the slight compression bump. In my case it was about 3 cc difference in the chambers.
I've never had it on a dyno, but I'm leary of the "calculators". They've come up with some very optimistic #'s and vary quite a bit, depending on what formula you use.
Last edited by Locomotion; 09/21/14 06:41 PM.
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Re: indy x heads on 318-390 build
[Re: Locomotion]
#1674626
09/21/14 07:08 PM
09/21/14 07:08 PM
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Joined: Jul 2006
Posts: 9,366
Lehigh Acres, Florida
rickstershemi
master
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master
Joined: Jul 2006
Posts: 9,366
Lehigh Acres, Florida
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Quote:
Just like the 1.88" vs 2.02" in the same OEM head, I don't believe it would be a lot of difference, everything else being equal. But the more radical you go, the bigger the difference will be.
I've run low 11.20's @ around 117 with those LAX heads with no porting, 360, 10.5 compression, .474" cam and footbraking a 904 @ 3,540+ lbs! Both as cast, but blueprinted and a good valve job, I figure they are at least 2 tenths faster than comparable OEM 1.88" heads. Ports are bigger and flow better, plus the slight compression bump. In my case it was about 3 cc difference in the chambers.
I've never had it on a dyno, but I'm leary of the "calculators". They've come up with some very optimistic #'s and vary quite a bit, depending on what formula you use.
My 72 Challenger had a very similar build to yours Myron although a 340, same heads and compression, 11.2's @ 117 all day long 
Rickster
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Re: indy x heads on 318-390 build
[Re: rickstershemi]
#1674627
09/21/14 07:19 PM
09/21/14 07:19 PM
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Joined: Jan 2003
Posts: 5,895
Florida
Locomotion
master
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master
Joined: Jan 2003
Posts: 5,895
Florida
|
Quote:
My 72 Challenger had a very similar build to yours Myron although a 340, same heads and compression, 11.2's @ 117 all day long
Rickster
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