undersized nose bearing

[quattrorunner]

I've had some trouble with leaking from this area and came across the undersized nose pully seal in PP catalogue. I'm ordering it. It just seems like it's too hard to put the pullly seals in my nose bearing without squishing out some of it. (I've changed four in one year)
My question is if anyone knows about the undersized bearing and if it's common or what? Where is it undersized, outside diameter or inside?
Thanks

[Flat6pac]

-.10 is on the inside for cutting the crank #8 surface. This bearing usually doesnt wear because its under constant oil and there is no pressure except from the fan belt.
\Bruce

[quattrorunner]

So I guess that means that it will be a tight fit or no fit if it's wrong on the crank eh? That should be telling.

[Flat6pac]

If your engine is together and you dont know where your oil pressure is, pull the seal and take a piece of check paper and try to slide it between the bearing and the nose of the crank.
The check paper is .04mm if it slides in, the nose bearing is cut, .1mm at least.
Got burned on this 30 years ago, trying to find the oil pressure because I was told "no shop ever cuts the nose bearing".
Bruce

[quattrorunner]

I'll check it. I don't know what you mean by not knowing where my pressure is? I've been running the engine and my pressure is normal. Is that a telling symptom?

[cgarr]

From what I remember the oil feeds the crank from both ends, if your nose bearing is not up to spec you can loose a lot of oil pressure because of a poor fit nose bearing.

[quattrorunner]

I have drips, not more than just a drip every 15-30 seconds.

[KTL]

Originally Posted by cgarr

From what I remember the oil feeds the crank from both ends, if your nose bearing is not up to spec you can loose a lot of oil pressure because of a poor fit nose bearing.

Yep that's why cross-drilling is often a recommendation for a race crank. Cross-drilling gets the oil feed to #2 and #5 rods (cyls in the "center" of the engine) via a shorter oil path by intersecting other oil passages in the crank.

[KTL]

Also, note that with a properly functioning crank snout seal, you can still end up with a leak. That's caused by leakage past the o-ring that seals the #8 crankshaft bearing into the case bore. Point being is often times people can mistakenly think a #8 o-ring leak is instead the crank snout seal fail.

[quattrorunner]

Apparently this part(pulley seal undersized) is special order from Germany and I canceled it based on the fact I don't really think it's the mystery part I need. All other seals have fit fine on the crank part of the seal. My issue has been the pressing into my nose bearing and part of the outer area always squeezing out in the same part of the seal.

[KTL]

I have seen that seal interference problem on my 3.2L engine. I peeled the seal OD in one location numerous times. I finally said screw it, i've got to stop it. So I took a fine tooth file and chamfered the edge of the #8 bearing bore to stop it from wrecking the rubber coating on the seal.

[quattrorunner]

I have seen that seal interference problem on my 3.2L engine. I peeled the seal OD in one location numerous times. I finally said screw it, i've got to stop it. So I took a fine tooth file and chamfered the edge of the #8 bearing bore to stop it from wrecking the rubber coating on the seal.

Thanks.
I bought a Dremel specifically for that purpose. Hope it works

[quattrorunner]

Undersize was nt the answer. I beveled the edge of the nose bearing and smoothed it so that the pully seal would have a nice easy press in. I used curel T and it went in great. No more issues with the seal squishing out. I suspect that leak to be resolved.

[AlfonsoR]

Awesome tip KTL!!

[KTL]

Just have to watch out with the Curil T usage. In some instances it allows the crank seals (typically the flywheel end) to walk out. Best to install them with a lube that dries/disappears. I use spit.........

[cgarr]

Thats right, some "sealers" can almost act as a grease until set up. I like the permatex hard setting, its what we use on super charger seals that are under a bit of pressure.

[quattrorunner]

If it's not one thing it's another..
I'll report if it pushes out.
The ultimate sealant threat mentions it as well as Waynes book on the crank pully seal as well as the flywheel seal. I can only follow those before me cause Ive only done one engine rebuild and have no direct experience though by now I'm getting lots of experience with the nose bearing ans seal, more so than I would like.
I appreciate all experience and pointers I get here. Thanks

[quattrorunner]

Got the seal in got the engine back in and don't see any oil leaks on the pully area. Been driving it all day. Looking good.

[Walt Fricke]

I used some Curil T on one of the crank seals and was able to push it in with my fingers, which had me really nervous, especially since I normally anticipate a real rodeo with these - especially the flywheel end seal.

[quattrorunner]

I spoke too soon. It's weeping. I just cannot tell from where while the pully is installed.