M-1 0w40 and RL 10w40...moded 396 LT1

[jason07-1zzfe]

carl, about the valve seals... I used to think you should get the smoke too...that's why it took me so long to figure out mine were bad. But this is in an 89 BMW with now 195k miles. I haven't changed mine yet, just made some oil changes to slow effects for now.
Just letting you know there doesn't have to be smoke on startup. No matter how long it sits.

 

[69 Riv GS]

quote:

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Rubber seals are the way to go and not teflon, correct?

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Yes, Viton and Rubber w/ Teflon inserts are the best.IMO

 

[OffOrWFO]

It's been my experience on my V8s that the valve guides only cause oil smoke on start up when a warm engine sits 15-30 minutes. I think that if you let the engine sit overnite the oil runs past the rings resulting in no smoke on start up. Also engines that have known guide problems smoke during a shift/high vaccum situation after full load. Are you running roller rockers? I understand that roller rockers decrease the side load, if any, on valve guides resulting in less guide wear. Just some thoughts. Hope this helps.

 

[carl97ss]

AGAIN, THANKS FOR THE help ON THIS.
I put a filter on the side port line to the valve cover and ran 90 miles this weekend. Not a speck of oil in it. I removed the throttlebody after the trip, and there was a bit of oil dripping down the back of the throttle plates. It was cleaned friday nite. Looks like it could then be the valve seals?? IF SO, THAT'S AN EASY FIX. I just wonder though, as the engine smoked when first built in February 2002 and then the rebuild in April 2003. Obviously both times w/ new valve seals. I don't know what kind of seals he used. Perhaps he used a teflon or sythetic rubber type seal. I need to call him.

The valve guides are a a "hardened" guide.

I run Comp Cams Pro Mag 1.6 full RR.

 

[69 Riv GS]

But, how do weak seals allow oil, into the intake manifold?

The best test, I know of, for valve seals is de-compression; High RPM, then quickly off throttle to coast down.

Full throttle really doesn't tax the seals very much because the open throttle blade/blades reduce the amount negative pressure in the seal area. Stated another way; during the intake stroke the piston is creating "suction" in the intake port, mainly through the open throttle blade. With it closed more "suction" is placed on the seals.

Steve