Hi, I have a 2.4 SOHC 73 datsun 240z. I purchased a Schnieder cam kit, it has the springs and lash pads etc. I am still saving money for the rocker arms!

I have an e88 head and It has been ported, I just need to know how much i need to shave to bring the compression to 10 to 1. that is what the guy from Schnieder told me it should be at. I have no idea on the history of this head, so I need to know the correct stock thickness, and how much is needed to bring it to 10 to 1. The machinists don't have the specs on the datsun heads anymore, he told me to go online, I have been searching for some time and I thought that someone might now off the top of your head, ok stupid joke:disappoin

any tips would be great, cause I have never done this job on a datsun before.

thanks!!:cheeky:

Are you running a P30 block?

I am not sure, all i know is that my 73 240z is all stock with the origonal engine. I'll check tomorrow when i have some light.

Hi,

The stock L24 head thikness is 107.9mm.

be aware , removing any more than .030 and you will need to shim the towers.

Best way is to accomplish this is to cc the chambers on the head. If memory serves the 73 L24 had flat top pistons. Check to see if you have positive deck height or negative, this also needs to be measured. Once you have all the numbers (piston deck height + head gasket + head chamber volume + bore + stroke) you can follow the formula to figure out compression ratio's. Then you will know exactly how much material needs to be removed. But be careful like Beandip previously mentioned if you remove more than 30 thousands you will need to shim the cam tower.

I don't have my notes so I can't help you any more on figuring out your compression ratio, sorry. Maybe Phred still has his ears on .

How many chamber cc does a standard E31 have, anybody?

Guus, it should be something around 42cc... 42,4? :beard:

I just need to know if anyone has done this before and can tell me how much to mill off the stock head. and how thick it was afterwords:knockedou

I don't think anyone will have the same exact set-up as you so no one will be able to tell you exactly. I would think the machinist would measure the chambers and tell you how much he needs to take off.

On my e-88 I put the bigger valves in and unshrouded my combustion chamber and milled .012 off and also took off .010 off the block to clean it up. The machinist c.c.'d the chambers at 41.5 cc which are smaller then the e31 head, but I also notched my block for the bigger valves so my C.R. was figured at 9.55.

So for someone to tell you exactly would be tuff.

By the way the head measured out 4.254 inches

http://www.zcluboftexas.org/128combo.html

LARRY