I was thinking the same thing.

I am building a 3.0 l SC motor and could use some assistance.

Could someone please confirm the part# for the GT3 Main Bearings? The number mentioned above does not come up with the correct part for me?

Also I would like a part# for the GT3 Rod bearings

Thanks

John

What is the deal with the colors on the GT3 crankshaft and main bearing sizes?

Porsche Motorsport lists 3 part numbers for 2004 GT3 #2-7 mains: 996.101.232.91 as well as numbers ending in a .92 and a .93

The .91 is for a Red marked crankshaft, .92 for a Yellow marked crankshaft and .93 for a Blue marked crankshaft.

The #1 bearing has a similar number/color scheme as well. 996.101.231.91 & .92 &. 93 for Red, Yellow, Blue cranks respectively

The Porsche street catalog only lists the .92 bearings for the #1 to #7 bearings, not the others.

Con rod bearings are 996.103.121.94 with no color references and is the same number in both street and motorsport books.

The #8 is the same old 964.101.138.01 number we know and love.



What is all this about?

Also, if one had in hand a fresh set of the Glyco bubble packed bearings that look very nice, would you go Porsche Motorsport bearings anyway with a GT3 crank?

Talking to Don at EBS, it seems that Porsche divides the GT3 crankshafts into size groups as they do cylinder groups and the bearing selections are for tighter control of the clearances.

My theory is that after production QC check that more cranks come out "nominal" in the middle = the yellow cranks and thus end up in street engines and the red and blue marked cranks are the plus and minus from nominal dimension cranks that are fewer in number and therefore go into the race engines and why only the .92 bearings are available from dealers.

So do we need red / yellow or blue for a street 89 930?
Thanks

What is the difference in measurements between Yellow,blue or red?
will these GT3 bearings fit a 1986 3.2 mains?
Thanks

I cannot locate thread tools on my iphone, sorry.

Bringing an old thread back...

Bought the glyco main bearings and also found them .0005 thinner than my old bearings...

So, do gt3 bearings work in a 88 930? Anyone use the calico bearings mentioned?

From what I understand the Glyco main bearings are fine to use in a street or track engines. It's the Glyco rod bearings that are not good for engines built for sustained high RPM track use. The right bearings are the ones made by Automobile Associates with the calico coating. These are available through pelican

My understanding is Glyco only had a short run of bad rod bearings. I took mine apart after 5 years, and they were totally fine. I'm 600 hp give or take, rev to 6750, so I've definitely put some decent stress on them. I'm sure 8000 RPM stresses more than hp, but no problems on my end.

Both the glyco main and Clevites rod bearings, which is what I have, look fine.

That's not the issue. They are thinner than the old bearings by 0.0005. Making my clearance .001 greater, putting it out of range for spec...

Why they are thinner I have no idea, but they are, as others have noticed... I kind of wonder if Porsche at the factory simply used bearings that were thicker depending on crank size.

Was going to use plastigauge to check case clearance today, but cleaning the case took waaaay longer than I thought....

The crank is in spec, on the low end of spec. Looks new, 55k miles or so. Not a scratch on it. With current old bearings all works fine... Putting in thinner bearings will lower oil pressure...

Ok... updates...

HM Elliot does do coatings, as Ollies posted earlier...

Cost is super reasonable. $5 a pair of rod bearings, $7 a pair of crank bearings...

Adds .0002 to .0004 to each bearing.

They do new and used bearings. The coating is a baked on Teflon coating...

They are doing this for a lot of cars whose bearings are NLA.

Cost is certainly reasonable... $30!


Anyone done this? Thoughts?

Teflon, as far as I know, is a hard substance... Risk to Crank?

Teflon is quite soft. No way it could ever scratch a crank, unless a foreign particle became embedded in it.

Really?! Gee my teflon pans are rock hard, can't scratch with a knife...