Oddjob

Anyone have problems with goetze rings not seating on a standard rebuild? Stock pistons and cylinders left alone - not honed.

Ski

not provided they're the right part number. The cylinders were round slightly instead of egg shaped?

I always used cheap dino oil for the first 200 miles, start out with straight 30 wt for 100 miles, then switch to a 10/30 for about 100 miles, then over to VR1. Just my routine when we've done engines.

Chris White

Yep – should not be a problem.
Keep in mind that any dirt or debris can get caught under or on top of a ring land. The rings have to seal against the walls AND the ring lands on the pistons. Did you thoroughly clean up the ring lands after pulling the old rings?

fast951

Did you prep/scuff the cylinders wall at all? How many miles on the block?

If the walls are ultra smooth (as in a running engine), new rings may take a while to seat if at all.

Oddjob

Not certain its the problem. Just doing some homework.

In discussing oil consumption and catch cans w/ Eric Steinel, he commented that he will only use Porsche rings after bad experience w/ Goetze. Thought it was interesting.

Symptoms are excessive oil through out the intake, and oil turns black immediately. But leakdown #'s at TDC were good, although it has been suggested that the amount of oil blown thru is sealing the rings for the test (not sure about that, I think a running motor would burn it), and to test leakdown at other crank positions to see if the bores have dimensional problems below TDC (also uncertain of the possibility of that occuring).

50k mile block. Nothing, no prep or scuffing of the bores.

Bores did measure fine. Ring gaps were ok.

Dino oil used on break-in. Currently about 3k+ on the rebuild.

Pistons lands were cleaned of debris, but nothing more.

Tom M'Guinn

Is it burning oil or giving you white/blue puffs out the exhaust? Have you tried a good ol' fashion compression check? When you say "excessive" oil in the intake -- how much are we talking? It took my motor quite a few miles before the oil in the intake started to descrease (at least 2 or 3K), although my oil stays golden colored for quite a while after a change...

Euro951

I used goetze without a problem, no smoke, no oil consumption issues, ect... Just gapped them to specifications and installed them like the manual advises.

Oddjob

It often smokes quite a bit on startup. Maybe a teaspoon of oil will run out of each of the intake pipes when those are pulled. Probably 1/2" of oil sitting in the intercooler anytime its checked, have had to periodically drain oil out of the CV and out of the WG diaphragm, etc. Dramatically more oil throughout the intake system on this car compared to the 3 other 951s I have owned.

Motor has had 3 different turbos on it, one low mile, one rebuilt, and one factory new - so unlikely that the oil is coming past the shaft seals.

Two different heads on it, both have had valve jobs and seals replaced.

The fact that the oil darkens within a few miles (this is a track car, so maybe within 50-100 track miles the oil is jet black).

Have done several compression tests and leakdown tests, nothing in the results indicate a big problem with the motor sealing up. So I am skeptical there is a ring problem, but the oil keeps me thinking about it.

The local p-car shop said that certain 951 motors do use a lot more oil than others, for no apparent reason. But also commented that was most apparent when using aftermarket pistons, especially JE.

Again, the comment from Steinel about problems with Goetze rings is what generated my question here, has anyone else had issues with rings seating. I dont recall hearing of anyone complaining about seating problems with stock rebuilds, so wanted to double check. I am not sure what could even cause it when using stock pistons and the leaving the factory bores (other than being dirty as Chris mentioned).

Chris White

Did you check the bores for taper and out of round? I have a block here that was to be reused and it had no taper – but the bores are out of round by over half a thou. Kind of strange!

Willard Bridgham 3

I have J&E pistons and racing rings and it took about 7-10k street miles to get them to seat and get oil consumption to < 3000 mi/qt. No track time on break-in. Block with first overbore and proper roughing-up.

My son's car took a lot of street miles, too, but they finally settled on a hot day track event. No work on block, rings/rod bearings only.

fast951

Have you considered installing a proper catch can in line between the AOS and the J-boost in front of the turbo? If you are getting lots of crankcase pressure and oil fumes, it'll fill the catch can.

Are you over filling the oil, above the "FULL" level on the dipstick? Is the dipstick the correct one for the pan/tube? What sort of oil temps are you seeing.

It might be a good idea to look at other possible cause and not just the rings.

Oddjob

Collected about 6-7 oz (little under 1/4 qt) out of a catch can over a 2 day race wknd. Oil was run up to the full mark and maybe down 1/8" from full on the correct stick. 240-260F in the pan depending on ambient temps.

Checked for taper but not out of round.

JohnKoaWood

Following with interest...

DDP

I've resealed a few engines with Goetze rings on old bores without any sealing problems.