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I just dropped my block and head off at machine shop. I have a stock bore z6 with stock length rods and vitara pistons, which ultimately leaves me with around 7.5:1 compression ratio. Frankly I am not satisfied with mid 7.5:1 compression ratio as a daily. So I told machinist to take .055 off the block and .015 off the cylinder head. .070 total mill. Should bump me back up to mid 8.5:1 compression. My question is will I have enough piston to valve clearance and also what kind of adjustments will I have to make with cam gear to accommodate the milling.
 

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BATSLOMAN GIVES NO FUCKS.
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wow. measure twice cut once.....better ask him to clay it before he machines too much off.

might have been easier to buy some eagle rods and save the headache.

an adjustable cam gear will be your friend
 

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wow. measure twice cut once.....better ask him to clay it before he machines too much off.

might have been easier to buy some eagle rods and save the headache.

an adjustable cam gear will be your friend
Eagle rods wouldn’t change anything since they are same length as stock rods.
 

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Im sure people have some experience with this. People have milled way more than .055 from block and way more than .015 from head. Just trying to get some insight on this. Still have to factor in head gasket thickness and so on
 

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BATSLOMAN GIVES NO FUCKS.
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it just sounds like a lot of effort when some rods would work and allow other sets of pistons to be used. to each their own.
 

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it just sounds like a lot of effort when some rods would work and allow other sets of pistons to be used. to each their own.
Not a lot of work it is cheaper for machine work than it is for aftermarket custom length rods. Honestly vitara pistons will hold way more power and boost than the stock sleeves so I can’t justify buying 500dollar forged pistons when I can make same power with100 dollar vitaras. I already have eagle rods so I just need to know if I will have enough piston to valve clearance and how much adjustment will be needed for timing
 

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Yea, those pistons will sit roughly .065" below deck height with stock length rods.

You should be OK to do the .055" on the block, but going more than .010" on the head I couldn't tell you. If you shave the head .010 and the block .055, the piston to valve clearance with a stock thickness HG will be very close to stock clearance.

I don't know what that measurement is exactly, so I'm not sure what taking .005" additional will do.

Hope this helps!
 

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Yea, those pistons will sit roughly .065" below deck height with stock length rods.

You should be OK to do the .055" on the block, but going more than .010" on the head I couldn't tell you. If you shave the head .010 and the block .055, the piston to valve clearance with a stock thickness HG will be very close to stock clearance.

I don't know what that measurement is exactly, so I'm not sure what taking .005" additional will do.

Hope this helps!
Thanks for the reply. Do you know what the stock clearance is?
 

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I don't know what that measurement is exactly, so I'm not sure what taking .005" additional will do.
Sorry man, not sure exactly. All of my stuff has been shaved/decked a couple times so I couldn't tell you what stock clearance is with the resources in my garage.

I'm sure that has been discussed before, a google search might find what your looking for!
 

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Sorry man, not sure exactly. All of my stuff has been shaved/decked a couple times so I couldn't tell you what stock clearance is with the resources in my garage.

I'm sure that has been discussed before, a google search might find what your looking for!
I have been searching on google hard looking for definite answers with no luck.
 
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