Rokket

My GT3 Cup engine is pretty whipped, with nearly a 38% leak down on all 6-cylinders. Deciding it was time for open heart surgery, I took her in for a "Pre Build Dyno" and the old girl only had 303 HP under her skirt.

So, I called PMNA about procuring new Std Rod & Main Bearings for my 2001 996 GT3 Cup as they have there very own special funky part numbers. I was boldly informed that PMNA does not sell ANY internal engine parts, but they would be more than happy to rebuild the engine for me....for $35,000!! After choking & gagging I decided it was time to hit Rennlist for info!

This is my 1st GT3 Cup, but I have been rebuilding 911/930/944/951 engines for about 20-years and have most of the P Tools required (including some of the specialized Stomski valve train tools). The 996 GT3 Cup cases are nearly identical to the air cooled models , with a few of the holes plugged off in the castings. Being Uber **** I want all of the parts on hand and readily available to start the reman project.

Here is the question #1: The Factory GT3 Parts manual lists the ROD Bearings as 930.101.132.05. 001 for Red, 930.101.132.05.002 Yellow, or 930.101.132.05.003 for Blue?? I am making the assumption that these are for undersized units. Are the GT3 Cup Standard Rod Bearings the same as a street GT3? If not, What is the difference??


Here is the question #2: Same stuff but MAIN bearings??

Any info would be greatly appreciated...Rokket

mkk62

Rocket

No wonder I passed you. Lol


Post on cup car forum (perf and competition). More help there!

C u oct. Hopefully with more hp!

Mike

Rokket

Hey Mike...You are just plain out FAST!! Now you are the guy to try & catch... Cheers Rokket

rbahr

Did you ever get an answer on this?

You may want to chat with Flying Lizards, TRG, etc and see if the have any left over stock...

I would like to know the difference between these parts

Ray

Rokket

I just completed the tear down of the 2001 GT3 Cup. The rods are the Pankl titanium/

The Rod journals were almost exactly 53mm and the Main journals were 60mm. Also, the rod bearings had the part # 996 121 94 with a date code of 09-04. The main bearings had the # 930 132 03 , 02-03 which I am assuming is a regular 964/930 bearing.

Anybody know the OEM specs for the 964/993 cranks? This will help me find the right bearing set. The cup cars part numbers are Voodoo and PMNA is not helping out in the search.

rbahr

Just sent you some links...

Good luck

Ray

Rokket

Hey Ray....WOW!! That is some great information for anyone with a GT3 cup to have. I was able to confirm that the cranks specs are std (53mm Rod / 60mm Mains). After scrounging, I may have unveiled Porsche's Parts numbering system for the Rod & Main.

The number on the Main bearings was 930.132.03, what they have done is left out the 2nd set of 3-digits which is 101...which denotes Main bearing group. So, after modifying the part number to 930.101.132.03...voila, up pops the number in the Porsche Parts system as a GT Main bearing, which also crosses over to part number 996.101.

I did the same thing with the Rod Bearings which were stamped 996.121.94. Added the 2nd set of 3 digits denoting Rod bearings 996.103.121.94 up pops the GT3.

The engine was sealed from PMNA so the numbers were not aftermarket.

Thanks for your help...Ill order these and let you know these work out!!

rbahr

Rokket: Good Detective work...

From the 2002 Cup parts list - you may want to look at page 120

Main bearing: 930.101.132.03.001 (Red)
930.101.132.03.002 (Yellow)
930.101.132.03.003 (Blue)

Con rod: 996.103.121.81
Thrust bearing: 930.101.131.05.001/002/003 (red/yellow/black)

Crank: 996.102.021.91

Ray

Rokket

Hey Ray,

Any idea what the Red, Yellow, and Blue mean??

Thank...Rokket

rbahr

clearance:

red is 'large' clearance
blue is 'small' clearance

I don't know how much under/oversized they would be - you could probably get in touch with a big name shop and ask...

Good luck!

Rokket

Well after a boatload of research and purchasing 2-sets of bearings, i now know the difference between the Cup and Street GT3 Set up.

The difference is minute, and all of the dimensions are the exactly the same. The ONLY difference that I can tell is the GT3 Cup main bearings do NOT have a dimple/notch in the bearing of the crank face which is used to hold the bearing into place. Rather, the entire bearing surface is smooth and flat with extra material added to the back of the bearing (as opposed to the conventional stamping) for the bearing holder/locking tabs.

On the other hand, the Street version has a very small recession in the bearing face where the holder is notched/stamped at the factory.

I don't know if this is going to be a big deal or not, as I have ran over 100K (hard driven) miles on a modified 930 3.3 on the exact same Glyco "street" bearings.

Will post a pic when I get a chance.

rbahr

So, does this mean that after the bearing is installed, for the same size bearing, the clearances will be LESS?

Ray

Rokket

The notch holding tab is the only difference

rbahr

Ok, I misunderstood

Where is this extra material? Is it where the tabs would go?

Thanks

Ray

Rokket

[ATTACH]853472[/ATTACH[ATTACH]853473[/ATTACH