head questions

[wengr]

Hello, my 2L fi head is off and partially dissassembled. I'm trying to get a feeling for what I should do to it while it's apart. The valves, springs, buckets, and shims look good. clearances on the bench were .011" to .015" intake, and also .011 to .015" exhaust. the valve guides are replacements with less than 10k miles on them. I have not removed the cams and pullys from the camboxes. Any advice on the following is much appreciated:

1. machine shop guy says he can check for warp, but since alum head require a high degree of flatness, his preference is is resurface them all as a matter of course. And especially if there has been an episode of overheating. He seems to be saying that you cannot straight edge the surface to the degree that would guaranty success. Would you agree?

2. I'm considering not removing the cams - just spraying down for cleaning the cambox\cam assemblies, replacing the seals and reinstalling. Any problem with that. Or if there is really some reason that the cams should come out, can I reuse the cam bearings if they look ok? motor has 77k.

3. Is there any leak test that I can perform myself while the head is off? What if I turn it upside down and fill the chambers with water? would this be of any use?

4. There was no sealant on the following gaskets: intake manifold, camcovers(cork), cambox, or anywhere else for that matter. Should I reassemble with bare gaskets as well? I have a gasket set from Vick's.

thanks in advance, Greg

[So Cal Mark]

1. I always check the head for flatness. There is a limit to how much resurfacing can be performed
2. No reason to remove the cams from the boxes, no bearings in the boxes either. Clearances are okay
3. don't use water, cleaning solvent or mineral spirits will work for leak testing
4. I use sealer on everything except the head gasket

[wengr]

1. I always check the head for flatness. There is a limit to how much resurfacing can be performed

Thank you Mark. so if I understand correctly, the head should be checked for flatness in order to avoid resurfacing if possibe? And therefore, you would tend to dissagree with the local guy's assertion that straightedging aluminum heads is insuffient? That was news to me but what do I know.

[skumandeth]

In my own experience I would agree with your mechanic, I almost always automatically have the heads surfaced for the same reason he said, now one thing to check for is if it has been surfaced before then there should be a stamp as to how much, I don't know the max on these motors but, you can only go so far and I don't think they make head gasket shims for these motors. But, if it hasn't ever been surface a couple thousands of an inch isn't gonna hurt anything and will give you much better success with your new gasket, also since no water goes through the intake I would not use any sealer on that gasket either unless there is some kind of damage to the manifold sealing face. (sealants, gas, and vacuum do not tend to be a good mix) Again this is from my own experiences.

[So Cal Mark]

each time the head is surfaced, you affect the timing belt and cam timing. I use a straightedge, and if the head doesn't need surfacing it doesn't get resurfaced. If it has .002 or more warpage, it gets resurfaced. There is a factory tool for determing minimum head thickness, but not many shops have it

[wengr]

I have looked for marks or indications that my head has been previously cut. on the front of the head it is stamped "A". also there is a three digit number iirc "571". I know from PO's records that the head was off for valve guides about 10k miles ago. there is no mention of resurfacing. No one here would have an appropriate gauge. Is the A and 571 typical factory markings or might they have some other significance? Also can the typically available adjustable cam pullys compensate for a slight head resurfacing or are they not adjustable to that small of a degree?

[skumandeth]

I have looked for marks or indications that my head has been previously cut. on the front of the head it is stamped "A". also there is a three digit number iirc "571". I know from PO's records that the head was off for valve guides about 10k miles ago. there is no mention of resurfacing. No one here would have an appropriate gauge. Is the A and 571 typical factory markings or might they have some other significance? Also can the typically available adjustable cam pullys compensate for a slight head resurfacing or are they not adjustable to that small of a degree?

I would say they are factory markings. If it's never been surfaced before then the .002 that it would take to surface it would not affect either tensioner or cam timing.

[wengr]

ok, my head is completely dissassembled. some more questions
1 valve guides on exhaust side are a lead color and are ringed inside, valve guides on intake side are brass color and smooth inside - no ring grooves. except that #4 on the intake side matches the exhaust side. Why the difference and is it a problem that one on the intake side does not match? they all seem in good shape with no rocking of the valve. I believe they are recent.
2 what can I soak valves in to decarbon?
3 what is proper sealant for studs that penetrate though?
4 I assume cam seals just pry out and seat new one with a large socket or something?
thanks in advance

[wengr]

Ok now I have a head resurfacing dilemma. head is apart and clean. I put a cheap wood worker type aluminum straight edge on it diagonally and every other way, and nothing, no light coming thru at all any where. Now obviously this is not a quality mechanics straightedge, but I would expect a bad edge to result in false gaps - not perfectly flat in all directions. I'm still going to take it to the shop to have a proper straight edge put on it. I know the guy will try and convince me to let him cut it. I really don't want to cut it for the reasons stated by Mark, but I'm really concerned about putting it back on and still no seal. I drove this car 25 miles with the temp gauge pegged, low on coolant as thermostat must have closed and forced half of it into the expansion tank. It was bad enough that there was no heat coming thru the trans tunnel from the engine compartment as there usually is. I really figured it would be warped. .002" is really small. Who says the shop's machine will be well maintained and can produce a cut with less than .002" variance? I don't know what to do.