Hi Everyone,
I had a set of custom valves and valve guides made for my turbo M103 project. The valve stems are 8mm exhaust and intake instead of the original 9mm exhaust, 8mm intake. I purchased two sets of valve stem seals hoping I could just use the intake seals and throw away the exhaust seals. However it seems the tops of the seals have a slightly different shape and look a little different in their rubber composition.
So, do you think I would be taking a gamble by using the intake seals on the exhaust side or will it be okay? I imagine, the only difference in wear and tear with exhaust vs. intake would be the heat that travels up the stem of the exhaust valve, this may be negligible though. Your thoughts would be greatly appreciated.
Thanks,
Adam

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Current Stable:
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!)

PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320

"Custom":adjective; Latin for difficult and/or expensive.
No Benz experience here, but with American pushrod motors we usually only worry about a seal on the intake side. The intake is always trying to draw oil in due to manifold vacuum, but the exhaust side does not. Also, the ex side needs more lubrication with the heat n all, so many circles say it's a bad idea to put a seal on it. If your ex stem is always drenched in oil then I would use a metered seal, which is probably what the oem ex unit is.

Yeah with the increased need for oiling on the exhaust side I would be careful with using a positive type seal on the exhaust side. I have worked with a twin turbo project on my chevy v-8 powered jag, and as long as the valve guides are good, there will only be back pressure on the exhaust valves with the turbo in place especially. I would recommend going with the facoty exhaust seals on the exhaust side, they are probably designed to allow for a little bit of oiling on the stems which will keep the stems cooler, straighter and less worn.

That's the problem though, I can no longer go with the factory exaust seals because the valve stem diameter was decreased by 1mm. I guess Ill have to find a seal from another engine that will work.
Adam