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REVTECHRACING.COM
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Discussion Starter · #1 ·
search button still screwed up, so i want to know how to determine my compression ratio of my new built motor?

my pistons are weisco 8.5.1. .40 over and eagles are stock sized rods. my head was done and a total of 10 thousandths was milled off. i have new hks 264's goin in and want to know if it will be needed to have a putty check for proper clearnace. i think i read somewhere i need .80 to be clear. please educate me to handle this the right way...
 

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REVTECHRACING.COM
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Discussion Starter · #2 ·
wow ,no one can help me out?hhmmmm. 1 or you must know hoe to do this?
 

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T88 YOU
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are you trying to figure out your compression or your piston to valve clearance? with those cams you should have no problems. if you want to know the compression ratio, you need to take some measurement. deck height, stroke, bore, combustion chamber volume, piston dish, just to name a few, and there is a formula to figure it out, but you need all the measurements first to do it accurately.
 

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ur moms favourite
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if 10thou was milled off the head, your static CR wont have increased much at all. If you think about it, the standard 2jz stroke is 87mm, you've dropped the head down about 1/3 of a mm - I assume you're using a stock head gasket?
 

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REVTECHRACING.COM
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Discussion Starter · #5 ·
i am useing a new stock head gasket and the head had 10 ths. taking off and the block deck was only just cleaned up. piston are the weisco 8.5.1. and hks 264's are going in. i am concerned about clearance for the piston 2 valves and dont want to go threw the putty check.. how much can be shaved off the head with this combo before the clearances are too close? and can i still run peak boost levels of 36 psi or above safely with the compression being higher now? i just want to do this right the first time.... no room for any errors. thank you........
 

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ˆê”Ô ƒGƒAƒ�ƒgƒv‚d‚q
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gmacrae said:
the standard 2jz stroke is 87mm

I've seen you say this before, so I thought I should let you know the Standard 2jz is a square 86mm X 86mm.



drift tt 23 said:
dont want to go threw the putty check.. i just want to do this right the first time.... no room for any errors.
Sorry I dont have a answer for you, but it seems you already know what you really should do if you are worried.

Also, no one can be sure that only 10thou were really taken off so I don`t think any one will say it will be ok 100%.

Please don't take my replies negatively guys, just letting ya know.

Ishii
 

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ur moms favourite
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Ishii said:
I've seen you say this before, so I thought I should let you know the Standard 2jz is a square 86mm X 86mm.
Ishii
Shit, sorry man, so it is, not sure where i got 87mm from
 
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