Rod Bearing Controversy

[MST0118]

If you're looking for the Clevite 77 rod bearings for a 2.4/2.7, try Scott McPherson from Automobile Associates of Canton, Inc. 860-693-0278. I just bought a set from him today for $290 for a 2.8 race motor and they are even calico coated. Armando from CCR highly recommended that I use those due to all the issues with Glyco rod bearings.

[Steam Driver]

Interesting that the Clevite bearings for those don't dhow up in the Clevite master catalog. But in any case I need bearings for the 3.0. I know those are supposed to be OK, but all things considered would you trust the Glycos?

[gtc]

Originally Posted by MST0118

If you're looking for the Clevite 77 rod bearings for a 2.4/2.7, try Scott McPherson from Automobile Associates of Canton, Inc. 860-693-0278. I just bought a set from him today for $290 for a 2.8 race motor and they are even calico coated. Armando from CCR highly recommended that I use those due to all the issues with Glyco rod bearings.

Can you post photos of the bearings?

[KTL]

Originally Posted by Steam Driver

Interesting that the Clevite bearings for those don't dhow up in the Clevite master catalog. But in any case I need bearings for the 3.0. I know those are supposed to be OK, but all things considered would you trust the Glycos?

Get the GT3 rod bearings since they are the same size as the 3.0L bearings. Part number is 99610312194. They're made by Glyco but seems to be a different material. They are black in color vs. the typical silvery bearings we're accustomed to on the older engines.

[GT2BH]

From what I've read there are no reported issues on the 3.0 rod bearings.. I've already put in my order.. if they are the same as the gt3 and made by Glyco, then the part number should be the same shouldn't it?

[Steve@Rennsport]

GT-3 bearings are just excellent. These come in 3 sizes so make sure you order the right ones after measuring everything. Your machinist should be capable of resizing the rods to fit.

[KTL]

They are the same size but they are not the same part number. Meaning, the 99610312194 does NOT supersede the STD 3.0L rod bearing part number 93010314800. Both part numbers are currently available. GT3 bearings are three times the price of regular 3.0L bearings. But the GT3 bearings are still a good value IMO.

[JonT]

Is there an equivalent 3.6L bearing available by clevite? How about 1st undersized? Thanks

[kenikh]

No 3.3/3.6 solution to date that I know of. Yet.

[911pcars]

I read somewhere that the Clevite 77 bearings for a domestic engine (Chevy) are suitably sized for 911 journals (rod and main?). Don't recall if main journals were modified to fit. However, all that must be confirmed. Perhaps the folks at Automobile Associates of Canton can verify.

In addition, I recall using 77 bearings in a domestic build many years ago. They're a relatively "hard" bearing for high rpm use (ideal for a race engine), with a top layer material hard enough to make the journal the sacrificial partner (on a domestic forged steel crank). YMMV on a properly heat-treated Porsche crank.

FWIW,
Sherwood

[tom1394racing]

Auto Associates has the std Size Clevite bearings for the 3.2/3.3/3.6 crank.

[DSPTurtle]

I remember this exact same thing. But when someone brought it up everyone shot it down cause the chevy's were so cheap. Now that they are four times as expensive they are popular? Wish I could find those old threads about Chevy bearings for 911s...

I read somewhere that the Clevite 77 bearings for a domestic engine (Chevy) are suitably sized for 911 journals (rod and main?). Don't recall if main journals were modified to fit. However, all that must be confirmed. Perhaps the folks at Automobile Associates of Canton can verify.



In addition, I recall using 77 bearings in a domestic build many years ago. They're a relatively "hard" bearing for high rpm use (ideal for a race engine), with a top layer material hard enough to make the journal the sacrificial partner (on a domestic forged steel crank). YMMV on a properly heat-treated Porsche crank.



FWIW,

Sherwood

[VFR750]

Are these 100% interchangeable?

If so, maybe the 3x premium is the acceptable choice for a 3.0 sc rebuild.

They are the same size but they are not the same part number. Meaning, the 99610312194 does NOT supersede the STD 3.0L rod bearing part number 93010314800. Both part numbers are currently available. GT3 bearings are three times the price of regular 3.0L bearings. But the GT3 bearings are still a good value IMO.

[911pcars]

Originally Posted by VFR750

Are these 100% interchangeable?

If so, maybe the 4x premium is the acceptable choice for a 3.0 sc rebuild.

Lacking other data, some judge acceptance by the mantra, "You get what you pay for".

Sherwood

[KTL]

VFR750,

Yes the GT3 rod bearings are 100% interchangeable on the 3.0L SC rods. They snap right in and work perfectly. Same dimensions as stock 3.0L SC bearings

Regarding the Clevite 77 bearings, don't confuse the "Chevy" application that has been mentioned here on the forums in years past. That is often mentioned in reference to grinding the crank & rods to accept a Chevy NASCAR (actually originates back to a Buick application) bearing. Two Inch NASCAR Bearings That trick to use NASCAR bearings in the 2.7 rods is not the Clevite 77 bearing that Auto Assoc. is providing. Note that 2.7 rod bearings are not the same dimensions as 3.2/3.3/3.6 (not GT3) rod bearings.

Since I brought up Glyco vs. original Porsche-boxed quality, I figured i'd take some pictures to show that it's not just a myth that Porsche selects their bearings and measures them vs. just taking whatever Glyco produces.

Here's a picture of a STD main bearing from the Glyco aftermarket box, the box itself and then an original Porsche-boxed bearing on top of its box. First picture is not real pretty but it's really not that bad. It's some discoloration of the anti-corrosion silvery stuff. Still, not all that confidence inspiring is it? Notice how the bearing on top of the Porsche box has three marks around it on each side of the bearing where they measured it.





Next here's some aftermarket Glyco rod bearings for a 3.0L. The bearing fit/finish actually looks quite nice as you'd expect. Notice the shiny backing and the 03-13 date code




Here's the GT3 bearing from Porsche with its apparent dry moly coating and measuring marks on it. Also notice in the second picture the blackish plating on the back and the Porsche part number (not present on the aftermarket 3.0L bearing or aftermarket main bearing)




Lastly, i'm not saying Porsche-boxed bearings are perfect. Look at the ugly #1 main/thrust bearings I received from Porsche earlier this year.

[GT2BH]

Not sure if this was asked before, but which GT3 bearings are we talking about? 996 GT3?

[KTL]

Both 996 GT3 and 997 GT3 use the same 99610312194 rod bearing shell part number. I don't know about 991 because those are too new to be able to get the parts diagrams from the Porsche.com website. Plus they blow up..........

[GT2BH]

Originally Posted by KTL

Both 996 GT3 and 997 GT3 use the same 99610312194 rod bearing shell part number. I don't know about 991 because those are too new to be able to get the parts diagrams from the Porsche.com website. Plus they blow up..........

but man are they great to drive.. I did a time attack event in the 991 GT3 and was blown away

[Europeanmotors]

I picked up a set of rod bearings (one blew and tore up my crank and one of my cams on my 3.2) from the host like 5 years ago, 20,000 miles in and no complaints yet. I wonder who the host sourced these rod bearings from.

[tocobill]

I contacted Henry @ Supertec about my GT3 bearings on the 993 rebuild I have. I was curious where mine where sourced from. I was told that mine were sourced from Porsche in Germany via Wrightwood Racing before being sent off to Calico to be coated. Makes me feel a ton better about this thread.