valve guides

[david.avrahami@]

If you need to replace the valve guides in a 1987 Carrera, is it preferably replace other parts while you are there? if yes what parts? Is there a complete kit offered?
Any suggestions as to what will the symptoms be to prompt doing it?

[afterburn 549]

If you replace the guides you have to redo the seats as the valves never end up where the were.
So basically you are talking about a valve job.
IMO replace all valves as they live in hell and not worth the risk.
DO NOT take your heads to your local machine shop as they will pull the guides out the wrong direction, split guide bores and cause all sorts of havoc.
Valve work is labor intensive . Craftsmanship.
Valve guide tools are a little special for Porsche.
I own everything as i do not trust anyone to a job as good as i can. ( I am anal)

[darrin]

you should keep an eye on this developing thread below -- in essence, you're looking to do a top end rebuild Proper Top End Rebuild

[HawgRyder]

I usually do my own valves and guides.
One of the first things I addressed was the ridge of junk on the port side of the guide.
The buildup of carbon will score the hell out of the head if it is driven through without cleaning it off first.
I found a "hole saw" with pilot drill of the correct size does a great job of cleaning off the carbon (take valve out..insert hole saw...drill away for a few seconds...presto...ready to drive out).
Helps if you heat the head a bit.
Then...to install new guides...freeze guides...heat head a bit (wife's oven...LOL)...take guide out of freezer...and it almost drops in.
After everything is temperature normalised....do the seats with a cutting tool...not a grinder...work carefully...lube guide often...clean out cuttings often.
Install new valves...I try to use sodium filled ones for the exhaust if possible...they last longer.
Good luck
Bob

[afterburn 549]

After installing the guides its a good idea to heat cycle the heads a few times to get them all to settle / shift "to" where they will be and not change after the seat work.
Valves - There are many to choose from and application needs to be considered. Street, strip, turbo, ETC
I have found drilling guides to a very thin shell "thread them with a tap " and pull them though the bottom.
After that its seat work and shim for spring Ht
Thats why P.car heads are so spendy. Lots of steps. not like a V8 at all

[DG624]

If you need to replace the valve guides

The expense seems large so I was delaying this until necessary. My advice has been if there is no blue smoke on deceleration after acceleration then the guides are not worn (leaking). Simple test but probably effective. A leak down test may also work but maybe not. If compression is equal and no smoke then I would wait. Does this seem reasonable?

[afterburn 549]

Its a sum of all factors
If you have your heads off, its silly not to inspect guides and valves.
If you have some wear now its not going to get any better.
Now or a little latter ?

[Tippy]

Have "cgarr" do your heads. He was a third of the local Porsche shop and turned mine around the night he received them. Unreal....