Compression

[LM1092]

If you have a k20 then it'll be 11.5, but you don't.

Use this: H/F Series Compression Calculator

Enter in the info and it'll give you what the compression will be. Or at least a very very close estimate.

Looks like if I did the ones rated at 9.0 they would work the compression on that with my engine would be 10.36

 

[Valet]

You could go a little higher.

 

[LM1092]

You could go a little higher.

The other ones would push it up to 13.41

 

[Valet]

Search a little harder for off the shelf pistons or order custom.

(Ricky Bobby voice) With all due respect, and I mean with all due respect, do you even know what you're doing?

 

[BlkCurrantKord]

Looks like if I did the ones rated at 9.0 they would work the compression on that with my engine would be 10.36

Without knowing exactly which pistons you were looking at...

With -

86.5mm bore (0.5mm over stock 86mm) and a -3.5cc dish

You'd get it to just under 11:1 compression. Deck the block, shave the head a few thousandths - You'll see 11:1 or a touch over.

 

[LM1092]

Without knowing exactly which pistons you were looking at...

With -

86.5mm bore (0.5mm over stock 86mm) and a -3.5cc dish

You'd get it to just under 11:1 compression. Deck the block, shave the head a few thousandths - You'll see 11:1 or a touch over.

These are what I'm looking at http://thmotorsports.com/brian_crower/brian_crower_pistons/cp7040/i-260856.aspx

and these are the specs http://www.briancrower.com/makes/honda/k20a3k24a_pistons.shtml

 

[BlkCurrantKord]

Personally I'd go with the CP70455 or 56

 

[komodomoe]

This is a stupid question, but obviously your CR would go up with boost. So, when you say the max CR an engine could handle that's regardless of boost, ya?

 

[Valet]

Typically that would be referring to static compression. But compression under boost matters as well amongst a plethora of other factors.

 

[AFAccord]

Go 11:1 and boost it. I see no reason for lowering compression with today's fuels and tuning devices.