Milling the head advice

[ZGjethro]

I am hoping to take my truck's head in for milling Friday. I am at 8000' elevation, and any more compression would help. I have the head off now, and I am wondering how you can tell how much you can take off. Is there a standard head thickness that will let you know if it has been previously milled? Do I need to take a caliper to each valve and see how high the maximum lift is? Any advice would be helpful.

I was surprised that the head was dead flat across the top of the piston. I expected some dome there.

What is a good method for cleaning carbon off of the top of the pistons, valves and block? Everything is in place now as I have only pulled the head investigating moisture in the crank case

[T. Highway]

I measured the valve heights with a depth mic and then checked the clearance on the head the same way. I would suggest consulting with your engine builder because there are several other variables that you need to keep in mind.

Bert

[ZGjethro]

T. Highway, there is no engine builder, just me. All I have is a digital caliper for measuring. I also do not know how much to account for gasket thickness. I might go with the minimum the machine shop recommends if I don't get any solid numbers here. The last thing I need is ruined valves and more. I don't have the time and experience to really tear into an engine right now

[T. Highway]

I know that my engine had what I believe was one government rebuild.
I to was not sure how much to figure for gasket compression but figured it at 50% but only saw about 20% after it was torqued down. I used the Best brand of head gasket with copper on two sides. http://www.bestgasket.com/pop_up_pictur ... umber=510C
I was told by my engine builder and a guy that races flatheads that .120" was the bare minimum clearance for the valves to the head.
After I measured everything, including how far the sparkplugs stuck thru the head (Just in case one of them was lower than the others) I shaved .080" off the head. My math data showed that I could of taken .130" off but I was not sure how this would work with my custom ground cam.

As for cleaning carbon off the valves & pistons you my want to leave them alone. If you get debris loosen and it falls down to the rings I would be afraid of locking up a ring and creating a much bigger problem.

I hope this helps but please don't assume that my numbers will work in your engine without double checking clearances.

Bert

[ZGjethro]

T. Highway, thanks for the replies. At this point I am eager to get my truck running, and I will probably go with the minimum the machinist recommends, since I do not have numbers to base a major milling off of. The truck was running well before, and I can always try it again over a winter when I have more time and I am not driving the truck. They salt the roads here and I don't want to rust the old girl out.