Replacing Valve Guide Seals?

My '78 SC smokes slightly, and has approximately 80K miles on a rebuild. The engine is coming out of the car for some other work, and I'm wondering if I should consider replacing the valve guide seals.

Is this a time intensive job, and can it be done without pulling the heads? Lastly, how do you determine whether it's the seals or the guides that are shot?

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Michael
'78 911SC Euro

to check guide wear, rotate the engine to open each valve 10mm and see if the stem can be moved much up and down by working it with 2 screwdrivers. they wear more on the valve head end. so if there's slop on the outside, there's more at the other end. the seals could be replaced by using "in the car" valve spring tools. more than a couple would be kind of a pain, but possible.

Thanks.......Perhaps I should consider pulling the heads and having it done completely.

What is the approximate cost of refinishing them (valve guides, seals, machining, etc.)?

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Michael
'78 911SC Euro

My recommendation would be to pull the heads and replace the guides, seals (with the white ones), and any valves that are out of spec. I would call Don at EBS (1-775-673-1300) and talk to him about this. They did my 3.2 heads and I thought their work was very good, and the communication excellent. The prices were as follows: basic valve job is $395. Includes new guides and stem seals and 3 angle grind. $495 gets you the same thing with some polishing and 5 angles on the grind. The valves, if needed, were $22 intake and $32 exhaust. As John Walker pointed out, it will be alot of work to do the seals with the heads in place, plus the problem is apt to be the guides or worn stems anyway.
Tom

My mechanic said $4500.00 to do this verry job. Is this a rip or what some one respond please.

$4500 is excessive, even though it no doubt includes engine removal, etc.

Also, I have recently read a Tech Note suggesting that the newest seals, with Viton rubber, may seal too well, preventing sufficient lubrication. Bruce Anderson may prefer the old style seals.

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'83 SC