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 displacement is -1.7cc.

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, 4:43 PM 12/21/2002]

 

With that calculator...

For the pistons click "other", than type in your piston displacement

For everything else, just use the type of parts you are using.

Block: B20B/Z but change the bore to 85 mm
Head: B16A
etc
etc

 

So what about the "piston-to-deck-height" at the bottom? Do I just use the stock number? Or does it has something to do with the piston specs?

 

This might help explain the problem.

 

When the piston is at TDC it should be .030" below the top of the block or deck, I think thats what piston to deck height is, but am not 100% sure.

The chart you have highlighted is the cylinder head volume, like if you turned the head up side down and filled up one of the combustion chambers with water, it would hold 38.6 cc's

 

Ok...but does the piston-to-deck-height depend on the block or the piston? I have a B20 block, can I just click on the B20/B18 Piston deck height or will the JE pistons change this varible?

 

I think it is dependant on the crankshaft (stroke) and the con-rod length. So I think it's dependant on the block. Hopefully someone else with more technical knowledge will chime in

 

ttt