main bearing alternative
 

in the midst of rebuilding my 3.0 spec racer motor and have been researching main bearing replacement options. good info in this http://forums.pelicanparts.com/911-engine-rebuilding-forum/666971-new-glyco-inner-ims-bearings-unusable.html and other threads on how bad the glyco stock has been of late. concerned about ordering through our host or other suppliers due to the fact that tales of ordering multiple sets and poaching the best units and sending back the others... :(

i am being told that as with the rod bearings, a set of the 04-06 gt3 main bearing will drop in and work. the crank was in good enough shape to just be polish, balanced, plugs pulled and will not be cross drilled. has any of the brain trust here heard this option? at about 2x the cost of the standard 3.0l glycos, but a 1/3 of whats been suggested by sourcing them from a dealer.

any insight would be appreciated.

t

The jack shaft bearing thread is not bad quality. It's poor packaging by Glyco. My last set I ordered came with the pieces combined in one box, so they could beat each other up in transit. I think sometimes it can be a matter of reducing packaging to simplify shipping? Reason I say that is because if the bearings are supplied as purchased, one shell individually, then you should get tiny boxes for each shell.

The Glyco main & rod bearing saga is a matter of poor quality control and the surface of the bearings are not precisely finished. However the GT3 rod bearings are very nice, and individually packaged. No worries IMO about the GT3 bearings.

I have always liked the packaging of bearings by Clevite...(later Michigan)..they take extreme measures to prevent touching of one to another.
Bob

so, i bit the bullet ordering the standard glyco main bearings and am happy to report the packaging issues seems to have made it back to the manufacture. check out the new, more protective packaging!!:cool:


http://forums.pelicanparts.com/uploa...1355347974.jpg

Yep the main bearings come shrink wrapped nicely like that. It's the intermediate shaft shells that are loose flopping around in a little box.

When I last got the GT3 rod shells individually, they each came in a heavy mil plastic bag

#8 main bearing comes in a box and is a big hunk 'o alloy. No worries about messing that one up......

How are the gt3 bearings different?

I had no issues with the generic Glyco main bearing packaging or appearance but they simply were out of tolerance for my crank/case combo while the premium priced official Porsche bearing set from our local dealer was well within spec.

I have had the same problems for a couple years now.

I am using the Porsche Motorsport GT3 mains in my 3.2 per recommendation by Don at EBS. Upon pre-assembly they spec'd out perfectly. More expensive than Glyco mains but cheaper than stock 3.2 mains from the dealer. I bit the bullet and got the Calico coated rod bearings. The Glyco intermediate shaft bearings I'm using look ok.

Where do you get the mains & IS bearings, and how much? How much extra for the calico coating? What are you using for rod bearings?

those sound like the mains that were suggested to me. could not get a part number, and could not find them here with our host, that's what generated this thread.

can someone direct me to a good thread that walks through the checking of the bearing/crank tolerance prior to the dry run reassembly?

Do you have a bore gauge and 2-3" micrometer that reads to the fourth digit?

I ordered the GT3 mains from EBS Racing in Reno, NV and they were about $300 not including the nose bearing. The part number (Porsche motorsport?) on my invoice is 996 101 901 02R. The IS bearings should be readily available as they are just Glyco; I'm sure our host sells them. The rod bearings I'm using are from a company called Calico Coatings: Ceramic coatings, Teflon coatings, Thermal coatings solutions | Calico Coatings. They are the Calico Race Series bearing and were (gulp) $580 for the set. Still cheaper than the dealer supplied rod bearings. I hope I'm not violating any forum rules here by referencing other vendors but I don't think Wayne sells some of this stuff :o

Porsche Motorsport part number: 996 101 901 02R

You need a precision bore guage and micrometer to measure the main bearings as installed in the case then measure the difference of the crank journal dimension. Or you can use the simpler, cheaper, less sophisticated method of plastiguage as I did. I installed the main bearings in their bores, lined each bearing with plastiguage, dropped in the crankshaft, assembled the case halves, torqued the through bolts. Then disassembled and checked the plastiguage on each of the seven bearing shells. Each bearing was an identical .002in. clearance. I also mic'd the shells and compared this dimension with the stock bearings that came out of the motor (virtually identical). All the bearings fit snugly in their saddles and look to fit perfectly in this application.

http://forums.pelicanparts.com/uploa...1355644102.jpg

http://forums.pelicanparts.com/uploa...1355644151.jpg

http://forums.pelicanparts.com/uploa...1355644182.jpg

Here's what the Calico Rod bearings look like

http://forums.pelicanparts.com/uploa...1355644481.jpg

http://forums.pelicanparts.com/uploa...1355644626.jpg

http://forums.pelicanparts.com/uploa...1355644733.jpg

GT3 rod bearings have some sort of coating on them that is different than the mains. I don't know the specifics

I tend to think that the GT3 rod bearings should be plenty sufficient for our use, given the nature of the GT3 engine- high rpm. If it's good enough for a GT3 8000+ RPM motor, they're more than capable for our mildly modified older engines?

Thanks for the heads up on the GT3 motorsport mains. I'll look into those when I send Don my order next week!

WOW!!! Those look really nice! Kind of sick i get turned by these beautiful little bearings. :eek:

That looks like the same coating I have done by HPC.

There should be some markings on the bearing shells to tell you who the manufacture is.

I am pretty sure Calico does not manufacture bearings. They are a coating company (and a good one). Last I dealt with them - a couple of years ago - I remember that they could get you quick turn around if you sent them new bearings in the box, as they had already coated a number of bearings often requested by customers. So your new ones were more like a core charge. Doesn't surprise me if they decided they could also just sell new ones they coated directly - though taking something for their trouble, costs, and risks out of the deal beyond just the coating and their supplier's charges to them.