Measuring head and block to calculate compression and quench size

[milkandoj]

I'm looking for information on where to take the measurements from to work out hoe much the head and block have been machined to calculate my actual compression ratio and quench area, on my vr4 6 bolt motor.

And what are the stock measurements are so i can plug it into one of the online calculators and double check it all.

I need to work out my head gasket thickness to keep my quench area and calculate what the actual compression will be in my piston choice.

 

[bazeng]

I CC'd my head.
Confirmed piston deck height.
Piston CC provided by manufacturer

Then ordered the headgasket to suit

As for actual specs or numbers............. does the overhaul manual have anything?

You can't be too sure anyway, just CC the thing...

How to measure:
http://www.diyporting.com/cc.html

 

[DOUGMO]

i cc'd my head, then got a piston on top dead, smeared grease around the top of the piston
and cc'd in there too.

Then calculate the area of the headgasket until you get the comp ratio you want.

 

[milkandoj]

I’ve read that quench height is "sacred' and getting it wrong could result in a hard to tune motor even if I keep compression low. So more importantly I need to know my quench height. Using a thicker head gasket to get the compression i want could ruin the quench height.

Can I measure the block and head and calculate this before ordering my parts, or do I have to assemble the shortblock then calculate my HG thickness I need to get my quench 0.0040 (between 0.0035-0.0045 inch is ideal from what I’m told and have read.

If there is a way, I want to work out the compression ratio I will be running when I have the quench height correct, using the correct gasket thickness.
Due to machining the head and block will mean ill gain compression on the quoted ratio of the pistons I’m buying, so may sway my decision to a different lower compression piston if im gaining too much.

 

[DOUGMO]

yes correct, to get my piston right up to the head I have taken 60 thou off the top of the block and run only a 1mm head gasket.
comp ratio is 8.4:1, it is very important and as you say a thick head gasket most often makes things worse