I have a set of JE pistons and the box says that the Dome height is 0.05. I'm using the C-speedracing compression calculator to determine my compression. So my question is what's the dome height? Is it the same as the "piston to deck height? Also the box says that the compression distance is 1.181, where do I punch these numbers into the C-speedracing calculator? Piston displacemnt is -1.7 cc.

http://www.c-speedracing.com/howto/c...c/compcalc.php

Please help my out. It's a B20 block with B16 head and 85mm pistons. Can someone help me figure this out? Thanks.


[Modified by GapxGuy, 4:39 PM 12/21/2002]

 

dome height and piston to deck clearence(height) are different. dish/dome volume is measured in cc's and is usually printed on the outside of the box. in order to get piston to deck clearence, you need to have at least one piston/rod assembly installed into the block. rotate the piston exactly to tdc. use a depth mic or piston to deck dial indicator tool and measure from the top of the deck to the flat part of the piston. to get a precise measurement, you need to rock the piston in the bore and take the two measurement. enter a negative number if the piston rises above the deck and vice versa. take the average of the two measurement and that will be the piston to deck clearence. compression distance(height) is no used when determining compression ratio. assuming your using a stock head gasket and bought the 10.5:1 pistons your compression ration will be about 10.54:1 using the the calc. at c-speed

 

So the "piston-to-deck-height" refers to the block? Using the C-speed cal., can I just click on the B20/B18 PTDH? Or does it also depend on the piston?

 

ttt

 

Yip. Using the settings you provided I calculate ur compression ratio to be 10.54:1

Here are the settings I used.
Bore: 85mm
Stroke: 89mm
CC/cyl: 42.70
cc/Piston: -1.7
HG: .0290
PtoDH: .030

 

Just like I was telling you.

https://honda-tech.com/zerothread?id=365706

 

Ok! Thanks guys. So you guys are 100% sure this is correct? So my total compression is 10.5:1? Can anyone else varify this or else I will start milling my head 0.02. Thanks again guys!