I bought a junkyard B21F (1982) cylinder head as a spare. Would like your opinion on its condition, any work that needs to be done, esp. the condition of exhaust valves #1 and #4. Please see hyperlinks to photos:

bottom of cylinder head:
http://www.geocities.com/menaster/1.jpg

Exhaust Valve #1:
http://www.geocities.com/menaster/2.jpg

Exhaust Valve #4:
http://www.geocities.com/menaster/3.jpg

None of the valves look burnt, so that is good. A little bit of extra crud on intake #1 but that is no concern. Intake #4 looks wet, but I can't tell from what. It might be a sign the valve guide and/or the stem seal is worn and sucking in oil. Or it could have been from a leaking injector. You'll have to be the judge on that.

Checking the valve guides is a job best done with the cam and springs removed and with a dial indicator, but you can do a quick check with everything in place. When each valve is fully open try to wiggle the valve side-to-side and see how much each one moves (shouldn't be 'very much').

It won't cost a bundle if it turns out you need new guides punched in, but the seats will need to be lapped.

Volvodad has it right, ideally it should also be crack tested and pressure tested by a competent machine shop before fitting.

Just two points, 1:- The bigger valves are the inlets, not the exhausts.

2:- For details of how to insert hyperlinks to URLs Click Here

It saves everyone cutting and pasting links (some people just won`t bother, particularly with multiple links)

Colin.

1990 740SE B200E/M47, remote C/Locking.

The thing may need no work at all - try this: With the cam (if it's in there) turned so that a given valve is fully closed, pour a little kerosene or paint thinner or similar distillate into the port of that valve, with the head held at an angle such that the valve is at the bottom of the port. Watch and see if/how fast the test fluid leaks past the valve. Compare all valves. There should be no leakage, or at most a slight "misting" of fluid around a valve seat. You might have lucked out. But also test for flatness of gasket surface as mentioned.
--
Bob (son's 81-244GL B21F, dtr's 83-244DL B23F, 'my' 94-944 B230FD; plus grocery-getter Dodge minivan, hobbycar MGB, and numerous old motorcycles)

There doesn't appear ( at least on the low resoloution monitor that I'm looking at right now ) to be anything screaming bad there. it looks like it would clean up prety nice. don't use a wire wheel on the mating surface.,. Assuming the thing is straight ( do the straight edge routine on it, or have it checked )and that the #4 valve isn't tuliped out ( cant tell by the picture, might just be the lighting ) you could strip the valves out , clean them up with a wheel, lap the seats in by hand and pop some new stem seals on and you should have a nice spare ready
--
-------Robert, '93 940t, '90 240 wagon, '84 240 diesel (she's sick) , '80 245 diesel, '82 Mercedes 300SD