Afr heads
Thread Starter
Race Director
Joined: Aug 2000
Posts: 11,506
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From: Vancouver,Wa.
Afr heads
I am thinking of assing some Afr heads to my ZZ4 with 3k miles on it. Here are my questions, The ZZ4 came with 58cc heads and the Afr have a 68cc. What will my compression be? And how much HP will I see over the stock #113 castings? And what is a heat risser?
TIA
Rich
TIA
Rich
Drifting
Joined: Nov 2000
Posts: 1,483
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From: Las Vegas Nevada
Re: Afr heads (corvette0096)
If memory serves right, you'll drop about 1.1 going from 58 to 68.
So figure right around the 9:1 mark.
I think you can get heads machined to give a smaller size, which would bump the compression back up.
As for power, no clue.
Matt
So figure right around the 9:1 mark.
I think you can get heads machined to give a smaller size, which would bump the compression back up.
As for power, no clue.
Matt
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Re: Afr heads (corvette0096)
Get the AFR190s and forget the rest. You will be MUCH better off and have better performance out of the AFRs. Just be sure to get the l98 angle. You can either get 58cc or56 for a little more squeeze.
I know others are gonna say to get the 113 casting and have them ported. WHY? You can get a set of stock AFRs for a little more money. Have a much better head. that will outperform the 113s with no porting. Or you can get the afrs and have them ported and be light years ahead of the 113 ported.
I know others are gonna say to get the 113 casting and have them ported. WHY? You can get a set of stock AFRs for a little more money. Have a much better head. that will outperform the 113s with no porting. Or you can get the afrs and have them ported and be light years ahead of the 113 ported.
Team Owner
Joined: Sep 2001
Posts: 62,146
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: Afr heads (corvette0096)
The drop in compression wont be too detrimental to performance, you could adjust it a little with the right gasket thickness. Hard to say what gain in power youd get, the ports on the 190s are bigger, so with everything else id expect at least ~10-15.
