Need help- Valve Guide Wear (limits)
 

While adjusting valves, checked movement of valve stem (with valves offseated approx.
5 mm ). I am seeing valve stem movement when I push valve spring from left to right. Should I be seeing ANY valve stem movement? Is this the proper procedure for checking valve guide for wear?

What I understand is that you must lift the valve slightly from its seat, then push the valve tip with a screwdriver and note movement.

I have not done this, but should have last time in; I just didn't know! I think what is intended is to "float" the valve by unseating it, letting you check the axial play from the "grip" the valve stem has on the valve proper.

Better minds than mine will know!

Jw

other than knowing that your engine has 150K and the guides must be history, the above mentioned procedure is the only way to check guide wear without a teardown. the guides wear more at the valve head end, so if you're finding noticable slop at the spring end, then it will be more at the valve end.

[This message has been edited by john walker's workshop (edited 04-02-2001).]

Wally,

A couple of clarifications:

1. The lift value at which the valve guide play should be tested is 10 mm.

2. The wear limit for intake valve to valve guide clearance is 0.15 mm or 0.006".

3. The wear limit for exhaust valve to valve guide clearance is 0.2 mm or 0.008".

If you have visible play, then I suggest that your '86 model probably has the later orange valve stem seals, which, in fact did too good a job of sealing and caused known excessive valve stem and valve guide wear prblems in 3.2 Carrera engines. It is probably time to do a top-end rebuild and valve job.



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Warren Hall
1973 911S Targa