What does "Getting Your Heads Done" actually mean?

[nwoods]

My Monty is not running properly, misses on at least one, possibly more cylinders. I don't know the source of the problem, but I know I have low compression on Cylinder #1 (35psi compared to 170psi optimal). I read through DJPurdue's inspirational thread and figure I might give it a try. But I have no idea what "Getting the Heads Done" actually means. What gets "machined" ? What kind of shop does this sort of work? Does anyone have any SoCal suggestions for a good (actually, I'm looking for cheap) shop?

Other questions - how far to I have to tear down the upper half? Do I have to remove the fuel rails and injectors?

I have already gone down to valve cover level on a previous repair effort, so that's not too big a deal, but I've never gone any further into an engine than that.

 

[Pdivizzle0112]

Typically a machine shop with flatten the mating surfaces by pressing it against a belt sander, check for cracks, remove and clean the valves, lap the valves if needed, replace all valve seals and clean the heads in a parts washer

 

[Pdivizzle0112]

You could do it yourself if your heads aren't damaged. Check them with a straight edge, clean the valves yourself with a wire wheel and soak the heads in top engine cleaner. No need to get crazy. Check the valves after with alcohol to to see if they leak and lap if necessary.

 

[evol911]

When I have heads done, I take them to automotive machine shop. There they are checked for flatness and cracks, skimmed to clean up and/or flatten the mating surface, valve seats typically are recut with a three angle cut, and then the valves are lapped in. Most shops will replace valve stem seals and some might even re-hone the camshaft bores. Sometimes valve seats need to be replaced due to pitting or excessive wear. It all depends on what you want to spend and the thoroughness of the shop. Some places will completely rebuild heads, cams, valves, hydraulic lifters and all.