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So based on that table and using the Calculator yields a CR of 10.8 (3 layer OEM headgasket) and 11.16 for a 2 layer type.
Notice the Head C'Cs is for a PR3 B16A/B18C Head. The head cc for your application will be 41.6.
Also take into account it is 0.5 oversize which will increase your displacement to 1819.8cc
it will also increase his CR
dam, so i should use a two layer gasget? to incress the compression ratio. keep in mind its not a type r, its a standard b18c vtec. so with these pistons, it should be all good. where do i get a two layer gasget?
Yes, if you took a stock piston and made it bigger, but then they change the dome height and stroke and that makes the CR of 11.1:1.Quote:
Originally Posted by ProECU
I would use a high performance gasket and maybe a turbo gasket as they are stronger. So a 2 layer is fine but 3 layer is ok too.
erm, I dont quite understand what you're saying.Quote:
Originally Posted by Slow96GSR
Piston manufacturers make pistons to displacement specifications, so you can get the same cc piston in 81mm and 81.5mm and so on and so forth.
My point was, If you keep piston displacement constant, the larger bore diameter will be a net effect of increasing static compression.
Dome height alone wont effect CR.
I dont understand why you brought stroke into the equation when the dude is looking to change pistons only??
Also, this is not true.Quote:
Originally Posted by Slow96GSR
Rod length does NOT have an effect on CR.
For those who are interested in how CR is calculated...
http://www.theoldone.com/articles/Ho...Ratio_calc.htm
so i imagine only dome height affects compression ratio, thus this having higher dome to stock?
I give up.
lol. so who does know about this.
how about you actually read and understand the info i've given you...
including that link.
The answers you are after are all there.
The Calculation of an engine's compression ratio ( C.R. ) is based on the formula :
CR= (SV+CV)/CV
SV= Swept Volume for one cylinder in CC's= Bore x Bore x stroke x 12.9
CV= Clearence Volume for one cylinder in CC's= HV minus EDV plus DV plus GV
HV= Head Volume (measured in CC's)= Best if measured because head volume vaires
EDV= Effective Dome Volume (measured in CC's)= Dome volume minus valve relief and/or dish volume
DV= Deck Volume clearance (piston to deck) (measured in CC's) = Bore x Bore x Deck Height x 12.9
GV= Gasket Volume (measured in CC's)= Gasket Bore x Gasket Bore x Compression Thickness x (12.9 or enter known gasket volume)
edit: Cubic Inch Displacement measurement
Bore x Bore x stroke x .7854 x 4(cylinders)
So yes the rod affects stroke and makes a difference in CR! I think what ProEcu is thinking of is displacement.
technically, if you are formulating a general formula, the rod length will effect CR, I agree with you.
In reference to this thread, the rod length of his combination is irrelevant, as it is being held constant, which is what i've been trying to convey in a simplistic manner for all here to understand.