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Discussion Starter · #1 ·
Can anybody tell me how much can safely be removed from a y8 head (std camshaft) on a completely standard y7 bottom end?
 

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BATSLOMAN GIVES NO FUCKS.
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Never finishes (TWSS)
91 Civic SI hb/ 01 GSR
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Ive gone upto .100" off a y8 head. But i had aftermarket cam and have oem pistons but valve reliefs cut deeper

I would think around 0.040" would be max for someone who had to ask about that.

You can very easily clay your motor then take off what you want to get your exhaust valve about 0.090" from your piston. Remember to use or calculate the head gasket thickness whilst measuring. Also lock vtec whilst claying the motor.

Take the clay thinkness you got by locking vtec, using ahead gasket and turning the motor over by hand. Then take 0.090" away from that..and that is how much you can go for PTV clearance on either valve.

Edit; common practice is 0.080" intake, 0.100" exhaust

Then deal with timing.

Its easier to deck everything you can from the block to bring the pistons flush. Then take the rest off the head.

Why do you want to mill the head? There are better ways to make compression.
 

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Discussion Starter · #4 ·
Ive gone upto .100" off a y8 head. But i had aftermarket cam and have oem pistons but valve reliefs cut deeper

I would think around 0.040" would be max for someone who had to ask about that.

You can very easily clay your motor then take off what you want to get your exhaust valve about 0.090" from your piston. Remember to use or calculate the head gasket thickness whilst measuring. Also lock vtec whilst claying the motor.

Take the clay thinkness you got by locking vtec, using ahead gasket and turning the motor over by hand. Then take 0.090" away from that..and that is how much you can go for PTV clearance.

Then deal with timing.

Its easier to deck everything you can from the block to bring the pistons flush. Then take the rest off the head.

Why do you want to mill the head? There are better ways to make compression.
Thanks for the reply, I ask as I have a y8 head with 1 mm milled off. Due to other more important projects this build isnt going to be in depth and I'd like to know if I'm able to fit the head as us without any more bottom end modifications. Once I have access to the vehicle again I can clay the engine for p2v clearance but I thought I'd ask if I'm going to be a way off before I reassemble with the y8 head.
 
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