9:1 3mm gasket

san supra

New Member
May 21, 2009
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san antonio
i have 9:1 pistions and a 3mm hks head gasket.

is my compression ratio roughly in between 8.4:1 and 9:1?

nothing is shaved on the head or motor.
dont give me a calculator, just your educated opinion.
 

gaboonviper85

Supramania Contributor
Jan 13, 2008
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1. You have to deck a used head to seal on an hks stopper gasket
2. Can't see a machine shop not decking a block for a rebuild
3. Don't tell us what to do
4. This sounds like fail from the gate
5. Get a calculator
 

san supra

New Member
May 21, 2009
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san antonio
haha this is hypothetical and i said educated u nay sayers.

I just dont want the gasket taking me below stock.

quit being fucks and tell me your guesses.

i dont need your negativity!

if yall represent the supra scene then i guess i will be a loner. A forum is to help, not to be a high and mighty ass. Help a fellow supra owner.

my head and block have been decked/machined and my motor is legit.
 

gaboonviper85

Supramania Contributor
Jan 13, 2008
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You asked the question wrong...you are going to be alone untill you ask it correctly! This forum is by far the BEST and MOST helpfull Supra forum if not general automotive forum on the net...if you don't get the answer you are looking for then odds are it's because you're asking the question like a douche bag and few of us have the patients to deal with it.
 

Zumtizzle

Can't Wait to Be King.
Oct 21, 2006
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How the fuck are we supposed to figure this out; without at least how much was taken off the head, the dish of the pistons, and how much oversized they are if applicable?

And no, You're under 8.4:1. ;)

Remember Static Compression means nothing; you worry about dynamic compression on these motors for obvious reasons.
 

gofastgeorge

Banned
Jan 24, 2008
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Texas
Well, I could post a bunch of negative comments just to run my post count up.....

And I may think these types of thoughts to my self.....
Because all the info is out there on the web.
Like figuring volume that a head gasket adds to the combustion chamber voluum.
(bore x bore x .7854 x thickness)
Which on an 83mm bore is approx. 8.25cc for a 1,5mm gasket,
and 16.5cc for a 3mm gasket.

And Wiseco publishes the piston dish volume on their pistons.
And there was just another thread here the other day on the 7M head volume.
So then it's simple math to figure compression ratio, as in this formula:
Cylinder volume + total chamber volume (head, piston dish, and gasket),
divided by total chamber volume.

All this info is on the web, and in any performance engine building book.
I suggest that you pick up a few performance engine building books,
and read up on this stuff.
You will be a lot further ahead than many people on any forum.
 

lewis15498

Don't blame ebay cheapass
Sep 28, 2008
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Raynham, Massachusetts, United States
san supra;1360225 said:
haha this is hypothetical and i said educated u nay sayers.

I just dont want the gasket taking me below stock.

quit being fucks and tell me your guesses.

i dont need your negativity!

if yall represent the supra scene then i guess i will be a loner. A forum is to help, not to be a high and mighty ass. Help a fellow supra owner.

my head and block have been decked/machined and my motor is legit.

1) Hypothetical or not this is a calcuator question, learn to use one.
2)First you said nothing was shaved and now your head and block have been machined.
3)Your head and block have been machined? I thought this wa Hypothetical, stop contradicting yourself.
4)You didnt give us the info we needed, piston type, bore, and how much was taken off the head and block.
5)Assuming pistons and bore are stock, you dont even need to calculate anything, if you want factory compression ratio, take what you took off the head and block, add that to the thickness of the factory HG and thats the thickness HG you should use. You would know this if you did a search.

This forum is to help people. If you came with a problem we would help you. But you didnt You came out rudely demanding we answer stupid questions to your liking because your apparently incapable of using a search engine, basic geometry skills, a calculator or your own head for that matter. So go ahead be a loner, take gofastgeorges advice and buy some books on performance engine building and while your at it grab a book on communication and people skills because you could use some.

Finally if you decide to stay here at SM give this a good read before you post again:
http://www.supramania.com/forums/showthread.php?p=230560