Glyco bearing quality

[MBruns]

I have gone thru 4 sets of 3.0 main bearings to find a complete set without some defects in mfg. has anyone else seen the QC slip lately in just about all eng. sizes. I ordered a set from the dealer today and not including the #8 they are almost 900.00 at shop cost !

Mike Bruns JBRacing.com

[911SCfanatic]

What are the defects you are finding?

[MBruns]

The batch I have on the bench now looks like if you painted a wall that had a nial hole in it and the extra paint ran out of the hole and formed a sag, that is what the area out of the oil feed hole in the main looks like and you can feel it, out of the 4 sets all but 3 shells have this problem granted they came from the same supplier and were most likely in the same run at glyco how did QC miss that many ? Some of the mains and rod brgs. from other size engines look as if they were cut on a band saw.

Mike Bruns

[cgarr]

You do really need to check everything dont you! Wait til you order a set of ATE Valves

[Steve@Rennsport]

Mike:

Without a doubt, Glyco bearing quality isn't what it used to be by long shot. Their QC is questionable at best and the Porsche dealers get the best ones.........

I noticed that Porsche Motorsports provides Vandervell bearings, now.

Some engine builders have gone to American-made engine bearings such as Clevite 77.

[gtihop]

I had the same thing with a set of rod bearings purchased from our host. Wayne took care of it right away and sent out another set.

[mb911]

Originally posted by Steve@Rennsport
Mike:

Without a doubt, Glyco bearing quality isn't what it used to be by long shot. Their QC is questionable at best and the Porsche dealers get the best ones.........

I noticed that Porsche Motorsports provides Vandervell bearings, now.

Some engine builders have gone to American-made engine bearings such as Clevite 77.

do they offer allot for porsche? or is it a bunch of cross referencing?

[Henry Schmidt]

We've noticed the quality dropping for quite a few years now.
That is why every bearing we install is hand sanded with 600 wet/dry and then dry film Moly coated. Although the bearing are not the highest quality we find this method of preparation adequate for even the high output engine requirements.

[MBruns]

Yes we have found the coatings to helpful, but the build up is at least 4/10 of 1000th per shell and with std cranks its not enough clearance for street or track, when we have cranks ground and heat treated we can spec the final size and use the coatings and thats hard to beat.
Thanks, Mike Bruns

[Steve@Rennsport]

Originally posted by mb911
do they offer allot for porsche? or is it a bunch of cross referencing?

They offer nothing for Porsche but Jerry Woods has them do special runs for him. I'd call him and see if they will sell them to you.

[Henry Schmidt]

Originally posted by MBruns
Yes we have found the coatings to helpful, but the build up is at least 4/10 of 1000th per shell and with std cranks its not enough clearance for street or track, when we have cranks ground and heat treated we can spec the final size and use the coatings and thats hard to beat.
Thanks, Mike Bruns

It has been my experience that almost every used crank that we have removed from a running engine shows some signs of wear. That wear coupled with a micro polish generally renders a crank/rod clearence more than acceptable. The moly coat does add thickness but that thickness is reduced by the burnishing effects during break in.
The moly is force into the pores of both the crank and the bearings making each piece gaul resistant to 170,000 psi when exposed to oil.

[cgarr]

Henry,

Are you usiing the Dry-Moly extreme pressure lube? and when used beer is not longer needed

[Henry Schmidt]

We actually use Dow Corning 321 Dry Film Lubricant.

It works well in engine to reduced bearing friction.

Beer will still be needed to loosen tight elbows when holding a pool clue.

[304065]

Steve, it turns out that Mahle bought Dana's engine hard parts business, which included Glacier Vandervell.

So there are two camps:

Federal Mogul, which owns Glyco and Goetze and Fel-Pro.

Mahle, which owns Clevite, Vandervell, Victor Reinz.

[cnavarro]

I've used Calico Coatings and know of quite a few builders that use their coated bearings successfully in race applications.

[304065]

From the Dow Corning 321 datasheet.

To obtain the best adhesion and wear life, apply a coating no more than 0.001-inch thick. A single wet pass of spray usually deposits a film of about 0.0005- to 0.0008-inch thick. Where uniformity is especially important, place parts on a screen during spraying to minimize excessive coating buildup due to “flashback.” Fitting parts on a jig and rotating while spraying also helps.

So let's see here, a coating thickness of 0.0005 to 0.0008 is 0.0127- 0.020mm. So two hundredths of a mm, this looks like a job for the Millimess to see how thick the coating is and how uniformly it's deposited. I suppose some before and after measurements are a good idea too before sanding the bearings.

The bearing shell for a 2,0-2,2 liter engine has a radius equal to the journal diameter plus the running clearance. The high limit of a bearing jounal is 56.990mm. The radius of the tip of the Millimess 1003 has a radius of 1,5mm, this should easily fit inside the bearing's curve.

[cnavarro]

John,

I bought a can of the 321 to try it out, and it's not the easiest product to apply in a single pass. I obviously need more practice, but I was thinking this stuff might be good for piston skirts for a cheap break-in coating, but the only problem I see is that if you use brake cleaner or denatured alcohol to prep parts, it will wipe the 321 right off.

I personally wouldn't build a tolerance in and accomodate for the thickness of the 321 as it does come off fairly easy - I could see the coating coming off and leaving greater than desired clearances.

[304065]

Charles,

I see we are thinking in parallel, my can arrived last week. I was thinking of a couple coats on the bearings to provide startup lubrication and to tighten the clearance with an ablation coating.

Crankshaft to main bearing clearance from p.25 of the little white book: +0.030 to + 0.088 mm.

Henry, can you weigh in here on what the bearings look like after teardown, as they are for a race engine? Is the Molykote still there?

[cgarr]

Charles, I just tried some tests with 321 on some old bearings, I cleaned them, applied the coating then put them in my electric furnace at 275, forgot and left them in overnight, well this morning I tried to remove the coating with brake clean and it would not come off.

[panama911]

so... this thread is more than 5 years old now...

Has someone in the meantime disassembled an engine and found the coating with Dow Corning / Molykote 321 still intact?

Or, can you find it filling pores in both crank and bearings, as suggested above?

Or is it just good for break in?
(I'm also thinking of using it on the chain tensioner shafts for an old engine with unbushed tensioners.)

What about heat treatment after application - yes or no?

Lots of questions, but it would be interesting to hear if there is long term experience with the use of 321 in our engines...?