engine and drivetrain 9.5:1 comp. 292 cam help

[quequieresvonmir]

I know very little about all this. I'm supposed to have 9.5:1 compression engine. In order to have 9.5:1 comp. (E12 head, piano top pistons), what would be/should be the head size? I noticed when I took off the head, the lower timing chain cover is .015" higher then the block. The head is .005" - .006" higher on the intake manifold side then on the exh.-manifold side. What can/should I do to fix it, or? Anybody?

Tia,

Adolf

[Guest Anonymous]

You're supposed to have the timing covers machined with the block & head so they stay the same height. If there's a difference I'd fix it now while the head is off or you'll have problems with leaks later.

[Guest Anonymous]

You're supposed to have the timing covers machined with the block & head so they stay the same height. If there's a difference I'd fix it now while the head is off or you'll have problems with leaks later.

Ok, I'll do that. But what about the head itself, what is the actual size if you have 9.5:1 comp.?

[BillWilliams]

by some formula that I do not have memorized but goes something like swept volume (cylinder volume bore x stroke) divided by unswept volume (head volume measured by some glass looking thing that inserts solvent into the chamber of the head) and then either adding or subtracting the gasket thickness.

Stop laughing you motor heads, I tried.....

[2761377]

2002 heads within bmw spec will be 129mm thick, plus/minus 0.1mm. bmw say this should not be reduced by more than 0.5mm during rebuild process. macartney claims you may remove 1.5mm to rasie compression, and with e12 head breaks it sown thusly- shaving 0.5mm wil increase c/r 0.435(9.935:1), 1mm for .87 and 1.5mm will increase piston c/r by1.305, or 10.8:1. so macartney says.

whatever, with a head that measures within spec and not warped, the pistons determine the c/r.

hth

robert

[Guest Anonymous]

Ok, here is some more info: Upper and lower chain cover flush with head/block. I correct myself: Head is .005"-.006" higher on the exh.-manif. side, not the intake manif. Head is not warped and not parallel. I checked 5.055"/5.056" intake manif.-side, 5.060"/5.061" exh.-manif. side. Would it be safe to use the same size headgasket like the old one or do I have to skim the head to make it parallel?

[Guest Anonymous]

Ok, here is some more info: Upper and lower chain cover flush with head/block. I correct myself: Head is .005"-.006" higher on the exh.-manif. side, not the intake manif. Head is not warped and not parallel. I checked 5.055"/5.056" intake manif.-side, 5.060"/5.061" exh.-manif. side. Would it be safe to use the same size headgasket like the old one or do I have to skim the head to make it parallel?