Dropping head @ machine shop need help!

[e30 gangsta]

Ok im basically getting a 3 angle valve cut. And decking the head to make it straight. My questions are as follows...

1. How much can i deck without messing up the timing and having the pistons slam into my head.

2. Anything else performance wise you suggest either than a cam and a 3 angle valve grind.

3. What do i torque the metric blue headbolts too?

Anything you would like to throw in about heads or anything that i should do to it would be greatly appriciated.

[backtrail69]

On the M10 heads there is a little dimple that shows how far you can deck the head. I am not sure about M20 heads. I torqued my head bolts to 80 lbft in sequence and starting at like 30 lb ft in increments of 10. Make sure the mating surface is CLEAN and that the holes for the head bolts are not filled with oil, use a q-tip to verify this.

[bddog]

Check your head with a straight edge and a feeler gauge.Machine shops may "flatten" it for you, just to clean it up.They love to machine things. Save it for next time if it doesn't need it.You can only go so far.
Clean the surface of the block.
Make sure to clean the head bolt holes out with compresed air.
Put a coat of oil on each cylinder wall.
Turn the engine over by hand. Take a rag and clean all the crap that comes to the top of the cylinder wall. Repeat.-- Steve

[e30 gangsta]

awesome thank guys

[bimmer8604]

Usually the machinist, if a good one, will have all the information he needs...

kyle

[MarshallM]

Have them shot peen it. What cleaning methods do they use? Something to look for is if a shop bakes the head, then sonic cleans. Also see if they run chaser taps through the bolt holes.