New 3.2 Glyco Rod Bearing with small side grooves

Classic11 · 08-02-2019, 04:26 AM

Hey, I have just received a new set of Glyco Rod Bearings for my 3.2. Just looking for some feedback that what I see is normal and others see the same and have used these bearings with success. I am aware of the past Glyco rod bearing issues with ones from South Africa, The new ones I received are made 12-18 so fairly new. What is see are tiny groves going sideways which is something I have not seen on bearings before. Any experience you can share?

Classic11 · 08-02-2019, 04:28 AM

MBruns · 08-02-2019, 04:38 AM

I have seen a big decline in quality over the years, depending what your doing with the car I would buy them from the Porsche dealer or get the custom set by Clevite/Mahle that Automobile Associates has made. 860-693-0278, ask for Scott

Mike Bruns

Classic11 · 08-02-2019, 05:05 AM

Car will not be raced or anything, just a driver to have some fun with. What I don't like about the Clevite Bearings is their hardness., I hear they are much harder then the Glycos so also harder on the Crank

MBruns · 08-02-2019, 05:43 AM

Well, with all things correct the clevite bearings are not going to bother the heat treated surface of a 911 crank, I have used them for decades, but sounds to me like the OEM bearings are what you need, be sure to check clearances
Mike Bruns

Classic11 · 08-02-2019, 05:51 AM

Yes, the OEM is definitely sufficient for the use of the car. But my question was not what kind of bearing to use but if the small grooves are normal, they go around the entire bearing, something caused by the manufacturing process I think.

MBruns · 08-02-2019, 06:17 AM

During mfg.would be my guess, I have seen the final coatings looking like a drip from the oil hole that you could feel, when I need stock journal sizes I go to OEM or call Scott
Mike Bruns

targa72e · 08-03-2019, 11:05 AM

the last set of Glyco 2.7 rod bearings I got were like that. I could feel the groves with a fingernail. Talked with EBS where I purchased them and they said it was not normal and took them back. I went with AA Clevite bearings instead.

john

bpu699 · 08-03-2019, 12:56 PM

It’s not normal, but I do wonder if it would impact performance of the bearing in any meaningful way...

Classic11 · 08-05-2019, 10:32 AM

Ok I just ordered the Clevites :-)

bpu699 · 08-05-2019, 02:55 PM

Quote:

Originally Posted by Classic11

Ok I just ordered the Clevites :-)

Just be aware the clevite increase clearance by .001 by design... looser fit than original Porsche. Your results may vary, make sure you check...

Classic11 · 08-07-2019, 04:51 AM

Hello bpu699, where do you have this information from? I assume to are talking inches? that is over 0.02mm which is a lot.

bpu699 · 03:46 PM

Quote:

Originally Posted by Classic11

Hello bpu699, where do you have this information from? I assume to are talking inches? that is over 0.02mm which is a lot.

Just call them, they will tell you. See my prior posts.

I bought the glyco ones and measured the thickness, they were thinner than my old ones...

Bought the clevite, they measured the same thickness as the glyco.

Bought the Porsche ones which were NOT expensive, and they were much thicker by .0005. The Porsche ones from the dealer were sold in pairs. I didn’t know that. So when I looked at the price it seemed high. I bought what I thought were 2 bearings, got 2 boxes, 4 bearings. Bought 2 more.

Called clevite, they told me their bearing are looser and intended for racing.

Again, that’s my personal experience. I recommend you goto harbor freight and buy a $30 micrometer good to .0001 and measure for yourself. Or call clevite. Perhaps something changed from a year ago, but that was my experience.

The clevite were .0005 thinner each, or .001 increased clearance over old...

Nothing against the clevite, lots of folks have used them very successfully...I didn’t want to give up any oil pressure.

Maybe the pros can chime in...

MBruns · 08-07-2019, 04:03 PM

They are designed to create more clearance which I welcome, with a strong standard crankshaft and the big end of the rods on the tight side the clearance is to little for performance and race applications when using OEM bearings, you have to torque them up and check them with a dial bore gauge to see, I have seen more bearing failure due to tight clearance and then they add coatings which further reduce it.
Mike Bruns

Classic11 · 08-08-2019, 01:12 PM

Thank you Mike for the information. Why do you prefer the extra clearance they add for race engines? More clearance, more oil loss less oil pressure but less resistance? But then in racing RPM's are high most of the time so oil pressure loss is probably not an issue then. I have heard it several times that some builder prefer it just never seen a good explanation.
Regards

Walt Fricke · 08-08-2019, 06:45 PM

Classic - one of the functions of bearing clearances is to allow the oil to flow and carry away the heat generated there. If no oil escaped you would have great oil pressure but super hot oil doing the work at the bearing. And Porsche 911 oil pumps can pump a lot of oil. Race motors (read more time at high RPM) generate more heat, so need more oil flow, not more oil pressure. So it is a balance.

MBruns · 08-09-2019, 04:12 AM

Walt is correct, heat is the biggest enemy and the fact race engines don't have the luxury to break in for several thousand miles, they warm up and go to work with designed clearances and oils that deal with those clearances, Sure there are high level race engines running journals with very tight clearances but the precise level of finishes and control on quality of parts and dimensions is not something most budgets could stand, using 0w- ?? synthetic oils free up pump drag and HP etc.. but it's not as easy as that. The volume that the 911 oil pump produces and looser clearances and heavier oils with tri metal bearings have worked very well even with the large squirters and spray bars they make plenty of pressure and plenty of volume. On street 911 engines with the standard engine spec's they have proven themselves for decades, really a race quality oiling system in a street car.
Mike Bruns