Crx Hf Block

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CrXRacr

Junior Member
Anybody know if any other pistons will fit in the hf block...im trying to ghetto turbo mine w/ the hf all motor monster article in the articles section...mines got a small rod knock and i dont want to blow it up right away...since im pulling the head ill hone the cylinders while the block is still in the car and get some new pistons and machine the crank....plus i just dont want to deal with swapping in a new motor. any suggestions?
 
I believe that most of the piston companies will custom make pistons to the right size and compression that you want, just give your favorite company a call, and they'll give you a price quote.
 
Im actually just looking for something a bit stronger than the stock hf pistons...like maybe the pistons out of a 92-95 civic dx? I just dont know if they're stronger than the hfs...they have the same bore and stroke, but the compression ratio is 9.2:1, as opposed to the hf's 9.1:1??!! do you think they'll fit??
 
Get zc pictons. I think they fit and thay are low compression which is great for turbo.


-eric-
 
Originally posted by 93tegh22@May 27 2003, 12:12 PM
Get zc pictons. I think they fit and thay are low compression which is great for turbo.


-eric-

The DOHC ZC pistons are low compression in the DOHC ZC engine. The DOHC ZC has a larger combustion chamber than the HF or the 92-95 DX (D15B7), and putting those pistons into a block with smaller combustion chambers would give you a higher compression ratio, not lower. You can't just go shoving one set of pistons into another engine and expect the compression to be the same as the donor engine's setup. It's not that simple. Please don't spout off incorrect information like this.

With some rough calculations, the DOHC ZC (PM7) pistons in a D15B7 or D15B6 (HF) block would yield a compression ratio of 10.7:1. That's significantly higher than the stock compression.

More rough calculations... here's what you would get with these pistons in your D15 block (assuming the HF head has the same combustion chamber size as the D15B7):

PM6 pistons (D16A6, 88-91 Si) = 8.6:1
P2P pistons (D16Y8, 96-00 EX) = 8.2:1
P28 pistons (D16Z6, 92-95 Si EX) = 7.7:1

I assume that all the OEM D series pistons are equal in strength since they're all cast, but I don't know what casting process is used on each set, and if the material composition is the same. Who knows which one is actually stronger?
 
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