shaaark89

andrew,
the oil you see in the bellhousing may not be from the rear main seal. on later cars (i think beginning in 90 or maybe 91) there is a drain port from the engine valley that empties into the bellhousing. if you have any oil in the valley that could be the source of what you see in there.
btw, gts baffle is worthless.

AO

Hi Tom-
Naah, I'm pretty sure it's from the RMS. It not a lot, but definately oozing. I used to have a lot of oil in the valley, but doesn't appears so now, but it's much harder to check.

BTW, I found that the oil discharge from the snout of the TS was contaminating my belts which made them slip which I think was causing them to get literally sliced up on the SC pulley. Since I cleaned that all up, the SC is running great! I've seen 8.0 on the boost gage! Sadly, that's when the clutch began to slip... badly!

Bill Ball

I was going to mention what Tom said too because the oil pattern is not what I have seen with RMS leaks. It looks more like a fine spray. RMS leaks normally just dribble down and come out the bottom of the bellhousing. Sure, the drip can hit the flywheel and get thrown around. That's what this looks like, but I have not seen such an evenly dispersed mess on the back of the block. Anyway, the outlet for the valley drain is a hole right above the RMS. Even though this does not look like the RMS leaks I have seen, I've only dealt with leaks on a few AT cars. The seal is so easy to replace, you should do it regardless of whether it is oil from the valley, especially if the seal is original.

drnick

andrew, you could put a baffle like the one pictured on louis otts page in there - i have.

JHowell37

How are your motor mounts? I don't recall hearing you mention them. Since you'll have the engine supported from above, maybe it wouldn't hurt to get some of those solid mounts from 928 Motorsports.

AO

I did the Anchor MM last fall. Since they've been in there for a year, I'll pull one out and give a report.

Carl Fausett

Andrew - early in the development of our SC kits, we were still toying around with blow-by issues and crankcase evacuation and all that. Many threads on the subject of crankcase ventilation of the boosted 928 are around - one of the better ones is:
https://rennlist.com/forums/928-forum/273110-crank-scraper-windage-tray-at-road-america.html

Anyway - one experiment I tried to reduce the amount of oil vapor in the catch can was to clamp down on the crankcase ventilation system - I thought for the moment that I was evacuating the crankcase TOO much.

When I did that, I blew the rear main seal right out into my bell housing mid-race.

Shows what can happen if the crankcase pressures are allowed to get too high.

I only mention it as you might throw a boost gauge on the crankcase somewhere and measure your crankcase pressure - I finally did that and it allowed me to know with certainty what the pressures were and if the changes I was making were effective in solving the problem.

AO

That's a pretty good idea. Where did you "tap in?"

Tony

I run a min of a 1" pipe in my system and use 2 homemade seperators that conatain numerous 90' bends internally. The more you turn it the more energy the airstream looses and the greater the odds that the oil in the vapor will drop out of suspension.

with some fiddling perhaps you could rig up some rubber tubing to the oil dipstick receiver..then to a gauge?
I know it can pop out if not secured properly, so it does see some pos presure.

.

Bill Ball

Good point, Carl! That sure may account for the mist spray pattern as opposed to the usual drip leak from a worn seal. As I wrote earlier, I was puzzled by the spreadout, even oil deposit compared to what I have seen with other RMS leaks. So, replacing the seal w/o looking at ventilation too would not help a lot.

AO

Got the flywheel back yesterday. It looks mucho better-o. Also picked up my stuff for the engine holder so I can do the oil pan, rod bearings, etc. Parts will be here on Friday, so tonight will be a big push to strip things down.

Peter F

That looks a lot better than before Andrew

As long as you are within spec. for minimum thickness per WSM you should be good to go.

/Peter

AO

You know... that's a good point to check. I assumed the shop that did it checked, but I'll verify that it's within spec. 27.5MM IIRC. Thanks.

bigmac

Andrew, let me know when the car is done so that I can break it in for you.

AO

I've seen you drive... and honestly, you probably would do a better job than me.