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Discussion Starter #1
Anyone know if i'm going to have clearance issues with my valves when using je a6 pistons in my d16y7?

I calculated compression (at 9.45:1) using -6.6 cc pistons with a 29.5 compression height at 75.5 mm bore (these are offered by JE for the d16a6 which yields 9:1 in the a6)

I am aiming for 9.5:1 so I would like to use these pistons but am concerned with the valve reliefs.

Anyone know? Thanks.
 

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Lifetime Awesome Member
'89 CRX HF
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according to the healtoe compression calc, the compression doesnt change when swapping between the a6 and y7 head.

so the compression should be the same as an a6 with those pistons
 

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Discussion Starter #3
according to the healtoe compression calc, the compression doesnt change when swapping between the a6 and y7 head.

so the compression should be the same as an a6 with those pistons

the calculators are wrong, the combustion chamber on the y7 is the same as the z6 at 34.6cc's so use that for calculations, sorry i forgot to mention it, but i believe i've shown you this in another thread ryan
 

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88 ED6
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I don't think there will be any problems; A lot of people run PM7/P29s in Z6s; those have non-vtec A6/Bx valve reliefs and a dome.
 

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Discussion Starter #6
yeah, i am feeling less and less worried. It isn't an interferance engine to begin with either.
 

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Brokedick Millionaire
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The JE pistons will have larger valve reliefs anyways.......
 

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Curious George
'99 LX Civic Sedan
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Valve relief are different from A6 pistons, valves are smaller, and exhaust valve gap between them is slightly different than Y series for example.

I got 2 set of a6 pistons in nice shape if you want.

thank you
 

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Discussion Starter #9
yes, i noticed the a6 (pm3 head) has the exhaust valves closer together whereas the y7 is totally opposite. I am going to have to clay the motor now. Hopefully the piston sitting .5mm below the deck will work to my advantage :)
 
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