Glyco vs clevite rod bearings - with data

[burgermeister]

I recall the recent glyco mains ending up with .001" more clearance than the 1988 or 1995 factory shells, because they were very consistently .0005" thinner. Which put the main clearance out of spec on my 3.6, as it was apparently at the top end of the spec. The GT3 bearings were the same thickness as the factory ones, so that is what I ended up with.

[mikedsilva]

Originally Posted by burgermeister

I recall the recent glyco mains ending up with .001" more clearance than the 1988 or 1995 factory shells, because they were very consistently .0005" thinner. Which put the main clearance out of spec on my 3.6, as it was apparently at the top end of the spec. The GT3 bearings were the same thickness as the factory ones, so that is what I ended up with.

This has been my experience as well.
Which GT3 did you use: RED?

[Dpmulvan]

Originally Posted by LukasM

They are actually quite a bit cheaper, $28 each per shell half so $336 for the set.

https://www.pelicanparts.com/More_Info/99610312194.htm?pn=996-103-121-94-OEM

So about the same price as Mahle Clevite. I haven't read about any comparisons in terms of longevity, but would tend to think that Clevite with their latest tech tri-metal (Calico?) coating would be better than Porsche OEM, where you are paying for Glyco shells that have been pre-checked (and maybe manufactured in Germany vs. Easterns Europe oder third world country)?

Would love to hear our experienced engine builders that have seen both of them up close, e.g. from race engines that see a lot of stress.

I’m talking main bearings not rod bearings.

[Dpmulvan]

Originally Posted by rudedude

I hate to bump old threads but I am wondering if the rod bearing controversy continues.
The picture I have is of a set for a 2.4 I am building and wasn't aware of an issue until I unpackaged and looked at these new glyco bearings from a reputable supplier. They are giving me a hard time as I wonder what kind of quality control they have. I would be interested if anyone would use bearings that look like this.
Thanks,
Jule

That’s not a coating defect it wipes right off with a rag or your finger.

[Dpmulvan]

However the tang end is definitely unacceptable.

[burgermeister]

Originally Posted by mikedsilva

This has been my experience as well.
Which GT3 did you use: RED?

Yep, I used the red. Had them coated.
I recall the Porsche set of mains for a '95 3.6 was something like $1800... the GT3 set was considerably more economical!

[porschedude996]

I have some questions about this bearing topic. Are there only three suppliers of these bearings (Glyco, AA, Calico, and Porsche Boxed Glyco)? Does AA or Calico make Main Bearings, and IMS Bearings? I can buy dozens of brands that are Clevite 77 for an american V-8 and have never an issue with bearing clearances.

[stownsen914]

AA is Clevite. I haven’t heard of other options for mains other than Glyco, but I believe GT3 mains are an option to the regular ones, at least for later 911s.

[porschedude996]

Originally Posted by stownsen914

AA is Clevite. I haven’t heard of other options for mains other than Glyco, but I believe GT3 mains are an option to the regular ones, at least for later 911s.

Wow, what limited choice for rebuilders. At least the Rod Bearings have options, but Mains is (Glyco SA trash, Expensive Porsche repackaged Glyco, which may be better. Is it only the rod bearings people are having problems with? And does Glyco make them, Main Bearings, in some other place than South Africa?

[stownsen914]

I can’t claim to be up on the latest with Glyco, but I’ve heard issues with their rod bearings, not so much on their mains. Would be curious if anyone else has heard differently.

Re: Porsche repackaged and GT3 bearings, I’ve heard they do actually measure them. Presumably that means discarding ones that aren’t to spec, for whatever it’s worth. For my in progress race build, I went with AA rod bearings and Glyco (regular) mains. The rod bearings ain’t cheap, but they are waaay less than another rebuild, that’s how I thought about it. The machine shop measured everything including the bearings, so hopefully I’ll be ok.

[dannobee]

The last set of Glyco mains I bought were from Poland. FWIW

[porschedude996]

Originally Posted by dannobee

The last set of Glyco mains I bought were from Poland. FWIW

I’ll take Poland any day. Carbone is in Poland and I have a huge respect for them.

[OSC911]

ACL bearings make conrod bearings for our 911s. They are made in Australia and are very high quality. I don’t know why they don’t make mains but I am sure they would sell plenty if they did.

https://www.aclperformance.com.au/engine/Porsche/Porsche%20930.10%202993cc%20Flat6%20SOHC%202v

[porschedude996]

Originally Posted by OSC911

ACL bearings make conrod bearings for our 911s. They are made in Australia and are very high quality. I don’t know why they don’t make mains but I am sure they would sell plenty if they did.

https://www.aclperformance.com.au/engine/Porsche/Porsche%20930.10%202993cc%20Flat6%20SOHC%202v

Thanks for that. Now this amazing, I found them on ebay. ($130)

https://www.ebay.com/itm/266346217383?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=0YyPGhAQTd2&sssrc=4429486&ssuid=zn12q52GSG2&var=&widget_ver=artemis&media=COPY

I may buy both the Glyco and the ACL’s on ebay and compare.

In their catalog, it describes the bearing thickness taper and why.

https://aclraceseries.com/images/85261_ACL_Bearing_Race_Series_Guide_US_Version_Web _Version.pdf

[targa72e]

Summit Racing has them as well. Std and -.25mm

https://www.summitracing.com/search/part-type/rod-bearings?fr=part-type&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=6B2462

john

[PeteKz]

Let me add a note to my previous posting on this thread: I used the CLevites when I rebuilt my engine 2 years ago. When I test assembled with Plastigage, the mains and rods were all right at .002" clearance. The engine is an OE 1980 RoW 3.0, stroked to 3.2, case not machined. The 930 crank was measured and polished by Dick Elverud. That speaks well of the QC on the Clevites.

[porschedude996]

If I read that correctly, you found Clevites for the Mains? (#1 thru 7)

[PeteKz]

I thought I did. I should go back and check my notes to be sure. I definitely used the Clevites in the rods. And I am sure that my mains and rods all ended up at .002" using Plasitgage.

[porschedude996]

Originally Posted by PeteKz

I thought I did. I should go back and check my notes to be sure. I definitely used the Clevites in the rods. And I am sure that my mains and rods all ended up at .002" using Plasitgage.

I thank you Pete! I would appreciate a reply on the Clevite mains.

[Dpmulvan]

Originally Posted by porschedude996

I thank you Pete! I would appreciate a reply on the Clevite mains.

Clevite doesn’t make mains for 911.