Installing new valve stem seals

[Scott98]

I started installing new valve stem seals tonight and thought I would share a few pictures. Pic 1 is of the valve spring compressor installed. I pressurized the cylinder with about 110psi to keep the valve from falling down. I used an attachment from a compression tester. Its the green hose in the Pic. Pic 2 is of the valve spring (smaller one is inside the larger one in pic), valve spring retainer and the two keepers. Pic 3 is the old seal. Pic 4 is the new seal installed.

Once you compress the spring, use a magnetic pick up tool to remove the keepers. Then undo your spring compressors and remove the springs and retainer. Note that the larger spring has a tighter winding on one side and that side must face the cylinder when reinstalling. I used some narrow access valve stem seal removal pliers to get the old seal out. It was really in there tight and took some coaxing to get out. Drive the new seal on with a 13mm deep socket. You feel it "snap" into place when its all the way on. By far, the hardest part will be reinstalling the valve keepers. Just be patient. I put a little oil on the inside of the first one to help it stick in place while I installed the second one.

I hope I didn't leave anything out. Maybe someone else will find this useful if they decide to do theirs.

Scott

[Scott98]

One more thing. If you get this far, this is an excellent opportunity to see if your guides are bad. Simply grab the valve stem and try to move it. If it doesn't move at all, you should be good. I think Porsche says 1/64th of an inch of movement is too much - measured at the top of the stem. Basically, if you can feel any movement, your guide is shot.

Scott

[Nitrometano]

how easy is the use of that valve spring compressor? I have the C-clamp style and I can only use it with the head taked apart.

[Scott98]

Originally Posted by Nitrometano

how easy is the use of that valve spring compressor? I have the C-clamp style and I can only use it with the head taked apart.

The compressor is extremely easy to use. Simply bolt it to the correct stud and crank down on the handle. You have to buy one for the intake and one for the exhaust. You must have them to remove the springs with the heads still on the car. You can get them for about $65 each at www.samstagsales.com or from Baum tools for about $10 each more.

Scott

[RoninLB]

how many miles on seals ?

what condition were intake seals ?

does engine normal operation temps affect life of seals ?
ie: does a 220F seal last as long as an engine operating at 180F ?


fwiw... I had to change valve seals on a 427 Chevy every 30k miles.

[Scott98]

Originally Posted by RoninLB

how many miles on seals ?

what condition were intake seals ?

does engine normal operation temps affect life of seals ?
ie: does a 220F seal last as long as an engine operating at 180F ?


fwiw... I had to change valve seals on a 427 Chevy every 30k miles.

I believe the seals are original (106k.)

BTW, I mistyped last night. There is a little wiggle room on the valve stem. Thats fine. You will know by comparison when you have too much wiggle. Make sure you decompress the cylinder, remove your old seal and push the valve in a little when you go to see how much play you have.

Scott

[john walker's workshop]

guides wear (taper) mostly at the valve head end, so it's hard to tell by moving the spring end. try some 964 seals instead of white teflon. less likely to come off or get crispy, and the rubber lip follows sideways motion of the stem (from worn guides) better than the stiff teflon ones.

[Scott98]

Originally Posted by john walker's workshop

guides wear (taper) mostly at the valve head end, so it's hard to tell by moving the spring end. try some 964 seals instead of white teflon. less likely to come off or get crispy, and the rubber lip follows sideways motion of the stem (from worn guides) better than the stiff teflon ones.

John,

My exhaust guides were shot. The valves drop down about an inch when the cylinder is at TDC. It is very easy to detect movement even with that little distance. Afterall, everything is removed from the valve - springs, seal, etc. The movement inside the guide on my exhaust valves was significant. You can easily tell the difference between a good guide and bad guide. I used the white teflon seals but, nevertheless, a top end rebuild is in my future.

Scott

[AUSTmike]

hi Scott....great closeup pics of the valves...I'm about to do my seals on my 2.7lt . Scott was it difficult to tap the rocker shaft out from the cam rack!...what was your method?

did you replace the rubber seals in the shaft?...once you undo the Allen bolt that goes through the center of the shaft whats the best way you found to tap or ease the shaft out sideways?.....

i will be replacing my valve stem seals with engine in-car!...cheers mike

[AUSTmike]

Originally Posted by john walker's workshop

guides wear (taper) mostly at the valve head end, so it's hard to tell by moving the spring end. try some 964 seals instead of white teflon. less likely to come off or get crispy, and the rubber lip follows sideways motion of the stem (from worn guides) better than the stiff teflon ones.

John....are you saying that the 964 seals are the same size as the older model 911 seals?....i will get the 964 seals if they are an improvement to the "OEM" seals of the 2.7lt 1977 911s model!...if the 964 seals are more heat resistent they may last alot longer right!... any info would be a BIG help!