where to get 8MM valve stem seals

std black neoprene ones, that will fit inside some narrow inner springs. thank you for your time.

Check with Greg,he is a member here. http://www.superformanceproducts.com/

Contact Goodson for some Viton press on seals that will press onto the stock valve guide bosses, way better controlling the oil on the valve stems than the stock slip rubber ones your asking for on that ride up and down on the valves

Alright, thank you!

Cab I see a "2 ring rubber" and a "teflon" & a "teflon & rubber" on page 39 & the listing says a machining tool is needed for all of the three. I'd like to avoid another trip to the machinist if possible. EDIT Oh is that tool just to get the OD correct for the seal & it will stay put? The tool does not machine any special grooves or something trick to grab the seal & keep it in place? If so, the guide nub OD might be OK as is.

The “common” two sizes for the guide OD when using aftermarket seals are .500 or .530.

If your guide tops are not either of those sizes I think you’ll have a hard time finding seals.

The “tool” can be used in a hand drill.

You’ll need the appropriate pilot as well.

5/16 and 8mm are only a few thou apart, so 5/16 seals will work fine.

Thanks Dwayne, let me go measure some more on what I got.

Like Dwyane said, 5/16 will be fine on 8mm. if you totally run out of options, you can grab some from AFR, as mostly everything they do is 8mm.

You need to tell use one thing: What is the largest OD of valve stem seal you can tolerate?

Then you get the ID of the sleeve part of the seal. If you are lucky your guide OD will be 0.500 or 0.530 and you can use stock Magnum motor seals.

If you need to machine the valve guides so the valve stem seals will fit on, you can do it yourself. You need an electric drill, valve guide cutter and pilot.

Attach the pilot to the cutter, chuck the cutter into the drill, lube the pilot and cut down the valve guide. It's that simple. On my '86 318 the valve guide was 0.625, and the stem seals were for 0.625. But the guides stuck up too high if my valve lift exceeded 0.474". So I bought the same cutter and a 3/8" pilot and 15 minutes later I had all my guides OD sized and made cylindrical, and the guides about 0.2" shorter.

One tip: The cutters in the tools are carbide and don't take kindly to shock. I was careless and now I get to hand finish the tops of the guides I cut down.

Total cost less than $100.

Study carefully before you buy. There are cutters for valve seats, cutters for valve guide OD, and cutters for valve guide height. Generally they are two out of the three, for example spring seat and valve guide OD, or valve guide OD and height.

R.

Good info Dog, I will get out there & measure & there's an inner spring that will be in there after breakin so yes dimentions will be critical. EDIT the inner spring ID is .690" and the metal nub OD is .534"