How much can I have shaved off my head and I don't want my hair cut.

[KyleTaylor]

I am having my head rebuilt I begin tear down this weekend, probably tonight actually.

Does anyone have a definite spec for clearance in a completely stock 1991 m42?  Not looking for guesses and opinion, but instead concrete math.

[nicknikolovski]

Check this out http://store.nexternal.com/shared/StoreFront/default.asp?CS=vacmotors&StoreType=BtoC&Count1=386989772&Count2=304130196&CategoryID=1&Target=products.asp

Click on Cylinder Head Gaskets and then M42/M44. This could be useful in determining the amount to take off.

Not sure about E30 M42 but I think they would share the same block and head with E36 M42.

In E36 service repair manual it states that the starting height of the head is 140mm (5.512 inchs)
The minimum head height must be no smaller than 139.55mm (5.494 inches). So really the most you can take off if required is 0.45mm (0.018 inches). Also if the head is warped it should NOT be machined more than 0.3mm

Hope this helps.

[KyleTaylor]

This data was exactly what I wanted!  Thanks.

[Isamemon]

puts me in a bind
my head is at a machine shop now
the most respected guy in town
Ill have to double check on monday
but he said my head was out .05 and that that was not a problem on the bmw's as l;ong as the head and front timing cover are planed together

is he wrong ?
am I looking for ANOTHER head ?

[nicknikolovski]

Yes, that means your cylinder head would now be over the minimum required head height. Get him to double check the measurement and tell him about these specs above.

[Isamemon]

I was wrong with what I thought I was told
head is within specs but will still be planed to level out
thanks