GT3 Crank Bearings.. do these look ok?

[IXjamesXI]

Anyone have experience with the GT3 mains bearings? I bought a set because I was wary of the quality of the stock part number for my 82 SC case given what I have read here about how poor they can be. These are the yellow standard bearings. They seem really unevenly finished.. smooth to the touch, but just not "right" looking to my eye. Anyone have experience with these? I look forward to your opinions, looking forward to slapping these into my case halves with confidence and I want to make sure that what I have in hand is good quality.. thanks.. pics below!

[Lapkritis]

They came from the package looking like that? Man, ugly bearings around the Porsche world if that's normal... If they're from Germany, maybe check if there's a manufacture date that falls during Oktoberfest. That might explain it...

[Mark Henry]

To tell you the truth that doesn't bother me, it's most likely stained from a etching (stop) bath. Just part of the processing.

What I do want you to measure, if you have the tools, is the thrust on the #1 bearing.
I see the Goetze package, can I see the back of the bearing manufacture stamp and does it say where it's made?

I have three sets of bearings here old used mid 90's Glyco, new Glyco (made in Poland), and new no name made in Germany that I will measure.

[IXjamesXI]

I can take some measurements I think.. what exactly do you want to see on the #1? The #1 did not come packaged with the others, and none of the packaging says country of manufacture. Perhaps you will be able to tell from the stamping on the back of the shell. I think if I recall the date of manufacture was Feb 2012, but I will take some pics this evening and post.

By comparison the GT3 rod bearings I bought look amazing.. they are black, and given what I have read leads me to believe that they have some kind of coating from the factory. Definitely very pleased with those.

[Mark Henry]

The dimension I'm most interested in is the thrust OD, use a mic or calipers. measure in several spots, Then set it in the crank and using feeler gauges tell me what clearance you have on the thrust. Install the largest feeler gauge you can without jamming the bearing, that's your thrust.
The thrust controls the back/forth motion of the crank, with the feeler gauges method you should see .003-.006"

The ID of thrust also important but you can just install it in the case it should fit snug with some drag but you should still be able to put it on/off if you have strong hands.
Also if your case specs out good, install some of the other shells, they should sort of soft snap into the saddle and sit just a hair proud if the saddle. Wiggle them slightly and they will come back out.

Below is a VW bearing (which is not split like a 911 bearing) but this is what I want you to measure.:

[mamut]

GT3 bearings should be bought directly from Porsche, reason been, they come color coded for the color coding in the GT3 crank, so that the clearances come up perfect, btdt, Stef.

[IXjamesXI]

Took just a minute to measure the outside width of the thrust bearing as depicted in the picture above.. got results between 27.85 - 27.87 mm, which would be 1.096 - 1.097 in. Haven't had a chance yet to measure with the feeler gauges. Garage and crank are at temperatures low enough right now that the measurement might not be useful for anything.. but I will soon. Here are some more pics.. anyone else using this combo and got feedback?





And for the heck of it and future reference for other bearings info seekers, here are what I was told are 996 GT3 rod bearings.. pretty nice looking..

[KTL]

I got a new set of mains from the dealer that look like that- uneven color. They're OK in my mind because they're dealer bearings that went thru the Porsche QC inspection. You can see the measuring lines on them.

The 996 GT3R bearings are black because they have less coating on them from what I can tell. I have a set of them waiting to go on the rods. The lesser coating would open up the clearance like you want it to be for high rpm/racing.

Best thing to do is measure measure measure like Mark said. That's the only way to know for sure.

I hear what mamut Stef is saying but most of us are not using the GT3 bearings with a GT3 crank. So the matching of color codes is a non-issue. We should be measuring our 930/Carrera or SC crank main journals, understand what the color codes indicate in terms of bearing dimensions above/below STD sizing, and select your colored set of GT3 bearings that way.

Ideally you would select your whatever size/color bearings suit you best in terms of how much you must grind the crank accordingly to get your desired clearance. But that can get expensive.... So you shoot for the best you can expect from the bearing sizing colors, knowing that what your crank measures is fixed- "it is what it is."

[ertech]

Should gt3 bearing come in a Goetze packaging or porsche?
Thanks

[Mark Henry]

Originally Posted by IXjamesXI

Took just a minute to measure the outside width of the thrust bearing as depicted in the picture above.. got results between 27.85 - 27.87 mm, which would be 1.096 - 1.097 in. Haven't had a chance yet to measure with the feeler gauges. Garage and crank are at temperatures low enough right now that the measurement might not be useful for anything.. but I will soon. Here are some more pics.. anyone else using this combo and got feedback?

Funny

My new no name "made in Germany" thrust 27.90mm giving me .003" on a 3.2 STD/STD crank
My new Gylco "made in Poland" thrust 27.86, just starting to jam up at .005"

Used glyco from the 90's (that's a guess) 27.89 can't get a .004 blade in.

I don't have a book in front of me to look up the spec but VW bug is .003-.006, if it's the same they are in spec but looser then old stock bearings.

Originally Posted by ertech

Should gt3 bearing come in a Goetze packaging or porsche?
Thanks

Add fuel to the fire...isn't that a glyco logo?

[mikedsilva]

Interesting thread...

[wprater]

I used GT3 red bearing to line up to my SC STD crank. they came with red paint on them.. you can see some of it and their overall look here in this pic.

https://goo.gl/photos/5dhDyN8rJcJT5hbdA

[wprater]

[KTL]

Where'd you source the color coded bearings?

[wprater]

Kevin, I got them from Don @ EBS.