The Stovebolt Site Forums The Shop Area Engine Shop Another 216 Question

So the 1951 216ci engine is mostly apart after a over heating problem and suspected bad head gasket. Turns out that the water jacket was fairly well plugged with radiator stop leak crap but I am concerned about the flatness of the head. How many thousands of an inch can the gasket tolerate? A precision straight edge shows a .002/.003" variation. I would think that would be okay but don't really know.

216 heads are notorious for developing cracks. I'd have a good machine shop do a .010" cleanup cut on the gasket surface, and do a magnaflux crack inspection at the same time. Heads can tolerate a lot of milling with no ill effects, at least until the intake valve to piston clearance gets too close. Up to 30 thousandths or so shouldn't be a problem, but don't take off more than is needed to get the gasket surface flat. Up to .005" is probably acceptable without doing any milling on a head gasket change, but as always, "the flatter the better". Don't forget to check the block with that straight edge- - - - -it's pretty rare, but not impossible to have a warped top surface on the block.
Jerry

Thanks for that response. I'm probably going to pass on the magnaflux though but will check the block. Hope I don't regret it.

Magnafluxing is not that expensive for peace of mind!

Absolutely magna flux. If the head is bad from cracks you will still have the problem.

Depending on how far down you have pulled the block, I would look into getting it boiled out. If it had enough stop leak in the head to cause overheating issues you might want to start with a clean block as well. .. If you are going to reassemble the head and run the engine I would use a block flush at that time and insure a clean block just the same.

Thanks for the replies and suggestions.
I am having this work done by a mechanic friend and when I went to see him the other day about it he had the engine mostly back together - the head was on in any case so no magnaflux or milling. He is going to remove a couple of the soft plugs to flush the water jacket out as the crank and pistons were still in the block. He did have a question about the front engine plate and gear alignment. The gasket kit came with two different gaskets for this and we are both guessing it is to establish correct gear engagement between the primary and cam gear. The manual I have does not address it and he could not find any info on it either. Anybody have any comments on that?

Unless you have removed the camshaft, there's no way to change the gasket between the plate and the block. The timing cover gasket might have some subtle differences from different years, but if you're referring to the plate-to-block gasket, compare them and use the one that matches what came off. Either way, there's no way I know of to adjust the fit of the timing gears.
Jerry

He did take the cam out. I'll forward this info to him.
Thanks!