944S valve stem/guide clearance

[wilkrod]

Hi all,
For an 87 944 S, I am wondering what the excepted service limit would be for valve stem/guide clearance for intake/exhaust valves?

I would like to measure each valve guide I.D. with a pin gauge, or bore gauge, and then measure the corresponding valve stem O.D., do the math and determine if the clearance is acceptable for a used part.

Trying to determine if valves/guides should be replaced by using a direct measurement , just don't know what the clearance numbers should be.

Thanks Much
Jeff

[kfanazini]

I understand what you are asking here, but I have to ask, why not replace the all the guides. I am in the same boat as you. Having removed the head on my 8valve, I need to replace one exhaust valve guide. From talking to people, and I may be wrong, but all have said to replace all the guides and seals. From what I understand the guides wear, and are supposed to, the valves not so much.

From what I understand replacement valve guides are .0025 larger in diameter, as the originals are nla.

This stuff is all new to me, so I am assuming that the head is going to need some machine work to accept the new guides, or will the replacements press in with enough force. (from a press)

I am interested in what you find out from this thread....

Originally Posted by wilkrod

Hi all,
For an 87 944 S, I am wondering what the excepted service limit would be for valve stem/guide clearance for intake/exhaust valves?

I would like to measure each valve guide I.D. with a pin gauge, or bore gauge, and then measure the corresponding valve stem O.D., do the math and determine if the clearance is acceptable for a used part.

Trying to determine if valves/guides should be replaced by using a direct measurement , just don't know what the clearance numbers should be.

Thanks Much
Jeff

[C ANDERSON]

Jeff,

I have the service book for the 2.5 S head . I will be away from the shop untill the weekend but would be glad to copy and E-mail it to you, Its only 3 pages. If I remember correct they use the tilt play method and it is at 10mm valve stroke with a wear limit of 0.80 mm


Clifton