Oldewoodupes

How much is too much? I'm getting about a thimbles full of clean oil in the air box after a 100km drive. Anybody know if this is normal or an issue? I was thinking piston blow by causing high crankcase pressure? Any other likely causes, hopefully something easier to fix

upstate bob

Oddly enough that is normal for these early cars, although not desirable. Try doing a full throttle run up through the gears and watch the smoke billow in your rear vew mirrow. There are more than one vendors who supply a corrective kit for this. I got mine from 928 motorsports and it worked like a charm. The downside is you will have to unbolt the waterpump housing to get that deflector plate in properly---at least I did. with 928MS kit there is the plate (goes in the oil fill /separator assy) and you have to drill a hole in the cam chamber for oil return (which is not difficult). I have no problems now, I can go full bore through the gears with nothing spitting back to the filter housing.

upstate bob

BTW, I omtted the extra step of butchering the strainer assy and installing the little cylinder thingys which came with the kit. Not necessary.

Oldewoodupes

Is this the part you are talking about? Definitely, easier than a rebuild. Thanks Bob��

Dave928S

You'll find a few iterations of a baffle for that location. Worth considering the one that Greg Brown makes, which I believe Roger at 928'sRus stocks. Here's a thread with a pic ... https://rennlist.com/forums/928-foru...tallation.html

scottpeterd

Well...

I was having the same issue on my 79 as well.

When doing a top end refresh, I installed this kit.

I also put a wad of stainless steel wool packing in the port on the airbox where the heated vent hose attached. I then put a small drain tube in the bottom of the port to drain any excess oil caught by the packing.

I also removed the god awful heated vent hose that had seen several kilos of silicon, tape and hose clamps from a PO. Replaced it with a Goodyear heavy duty flex hose.

I was just in the states several weeks ago to have a weekend drive in the mountains of Wests Virginia. Got on it coming on an entrance ramp to I64. Backed up before running up someone's tailpipe.

I could not see ANYTHING out the rear view. Car ran fine after a few minutes. No real difference that I could tell after all that work. But I have the satisfaction of at least attempting to solve the issue.

But I don't have anymore oil in my airbox!

Oldewoodupes

Thanks for the replies. Now that I know this is not uncommon I might just monitor it for awhile. If it becomes a problem I'll definitely be looking into one of these solutions.

linderpat

Yes, not a problem, just messy. I have one of the baffles, and it helps some, but does not eliminate the blow back by any stretch.