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Recommendations for bearings?

I'm going to need to purchase all new bearings and was wondering what manufacturer everyone recommends??

I know absolutely nothing about rebuilding an engine... so are there certain material/compound that I should be looking for when buying new bearings?

My crank is std/std so I would assume I just need to find a set of standard bearing? I'm guessing that a 'standard' bearing has a specific thickness to it?
Should I measure the bearings once I get them to verify what I have?
What is the correct bearing for my engine?

sorry to sound like a noob... as I stated, I know nothing about rebuilding an engine except what I've read and watched.
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Old 08-29-2018, 07:39 AM
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There are some threads, perhaps out of date, talking about bearings. Aparantly at some point in the past some defective Glycos got out there.

I used Glyco, bought from our host for my 3,0 build. However I measured every bearing to make sure there were no defects and they were all in spec. If you by Porsche brand bearings, they are also Glycos but the measurements supposedly have already been done.

There are other bearings available for a price.

Here is a recent thread. https://forums.pelicanparts.com/911-engine-rebuilding-forum/969825-new-bearings-supposed-thicker-than-your-old-ones.html

And https://forums.pelicanparts.com/911-engine-rebuilding-forum/787595-glyco-rod-bearing-issues.html
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Last edited by Trackrash; 09-01-2018 at 02:17 PM..
Old 09-01-2018, 12:47 PM
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I used Glyco but had dry film coated for main bearings but then used Clevite for rod bearings at the suggestion of various experts. My build was a 2.8 with 70.4 crank.
Old 09-01-2018, 02:02 PM
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I am in the process of rebuilding a 3.2.
I am using
Mains: 996 GT3 "red". these are a little thinner than stock, resulting in clearance at the loose end of spec. I reused the #8 bearing as it was within spec.
Rods: Clevite coated.
IM shaft: Glyco. I bought some cheap Glycos ( $6 each) but then was concerned about the clearances so bought Porsche bearings for several times the price. The Porsche bearings measured exactly like the Glycos, so I stayed with the Glyco.

It;'s hard to say what the " best" are without measuring your crank, rods, IM shaft, and case bores.
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Old 09-01-2018, 05:29 PM
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Why don’t you depend on the machine shop to supply the bearings, you’re dependent on them with every other part of the motor...
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Old 09-01-2018, 06:09 PM
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Quote:
Originally Posted by Flat6pac View Post
Why don’t you depend on the machine shop to supply the bearings, you’re dependent on them with every other part of the motor...
Bruce
They don't supply the bearings… they only 'machine' the parts and hand them back to me.

It is up to me to get the bearings... but obviously not all bearings are equal.
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Old 09-02-2018, 10:08 PM
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Quote:
Originally Posted by bdonally View Post

It;'s hard to say what the " best" are without measuring your crank, rods, IM shaft, and case bores.
What would I need to measure? I had thought I just had to order a set of factory clearance bearings.


I guess my question is more about what manufacturer makes the 'best' bearings?
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Old 09-02-2018, 10:16 PM
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I'm about to send all of my stuff off to the machine shop for measuring and machine work. I'm also looking into bearings and what is best.
I recently stumbled across via a internet search a brand of bearings called ACL Bearings.
I think they are Australian? There's only a few posts on here that mention them, but non Porsche people seem to love them, particularly Subaru people.
Unfortunately they only seem to make rod bearings - no mains, for the 911's. But they are apparently the bearings that take the real beating! Anyway - they are worth looking into! Not expensive either... $130 AUD for the set.

ACL - Race Series
Old 09-03-2018, 12:26 AM
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All bearings are not equal but you also don't have many choices. For mains, not including the #8 nose bearing supporting the crank snout, you've got aftermarket Glyco or original Porsche. For rods you've got Clevite/AA, Glyco or original Porsche.

The quality issue with the Glycos is real. They aren't as good as they used to be. The failure issue with the Glycos was isolated to the 3.2/3.3/3.6 and I believe more specifically it was those manufactured in South Africa. So your best bet is to spend the extra $ and get the original Porsche bearings.

I shared some pictures of Glycos vs. original Porsche and you can see the evidence of measuring the bearings on the original Porsche bearings. But, even the original Porsche bearings can concern some people because the finish coating is sometimes blotchy. Actually I don't think that appearance should be a concern because that coating is for corrosion protection to protect the surface until they're installed. My limited experience has been that the coating is so thin I couldn't even detect its absence with a .0001" resolution dial indicator.

Rod Bearing Controversy

The most important thing here is you MUST measure to be sure you've got acceptable clearance. Measure the main and rod crank journals with a 0.0001" resolution micrometer. Measure the engine case dry-assembled with the bearings installed (must install #8 nose bearing to align that end of the case) using a bore gauge with a 0.0001" resolution dial indicator.
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Old 09-04-2018, 06:58 AM
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I cannot argue this too well as I don't have a ton of experience with seeing rod failures, but I would think a wear case study for engines assembled with the big ends at the looser side of the tolerance range (.0035) to the tighter side (.0019), with various brands would be interesting and highly relevant. I'm hesitant to completely bail on a bearing brand until I know clearances and oiling practices.
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Old 09-04-2018, 10:30 AM
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As KYL said, measuring is needed to make sure the standard bearings will provide the proper clearances.
Rather than measure with the bearings installed, I dry assembled (several times) and measured the case bores, then calculated clearances using the bearing thickness.
I found that the surface of the bearings is really soft and, at least as an amateur, it is difficult to avoid marking the bearing shells with the bore gauge.
Also this approach let me see what shell thickness might be best. The 996 GT3 bearings are available in three thicknesses ( with a little looking) and allow a little fine tuning of the clearances without grinding the crank.
Measuring also lets you decide on reusing the #8 bearing, which is pricey, and, at least in my case, was within spec.
Same thing with measuring the IM shaft and bearings, and the rods.

lvporschepilot - a study would definitely be interesting but highly unlikely on these old cars. However, your comments about oiling practice triggered a thought. Once I knew all the assembled clearances, it assisted in picking an oil viscosity. In my case,
the mains are at the high end of the spec, so I decided to go a with a 15W50 oil.

Isn't it wonderful to be fooling around with stuff that has so many variables!!
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Old 09-04-2018, 10:44 AM
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Interesting that it was the #6 rod that failed. If oiling was an issue would it be #2 or 5 having the problem?

I can't imagine anyone assembling one of these motors without checking the bearing clearances. Plasti-gauge is a good way to confirm measurements, IMO.
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Old 09-04-2018, 11:13 AM
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Quote:
Originally Posted by KTL View Post
All bearings are not equal but you also don't have many choices. For mains, not including the #8 nose bearing supporting the crank snout, you've got aftermarket Glyco or original Porsche. For rods you've got Clevite/AA, Glyco or original Porsche.
well after reading your link... and then another link... and then another link... and so on... it appears that Glyco is NOT the brand to purchase.

Porsche branded Glyco is my only true option for the main and Clevite 77 HX series for the rods.


Now the question is measuring. Other than measuring the bearing thickness from all 3 points... is there anything else I need to measure?

I'm currently researching everything I need to measure when I get all my parts back. The tough part is going out and buying the correct tool.
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Old 09-05-2018, 01:34 PM
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Plasti-gauge is a good way to confirm measurements, IMO.
How accurate is this process?
It just seems like it's not very accurate, as you have to kind of 'guess' what picture matches the squished piece of plastigage.
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Old 09-05-2018, 01:52 PM
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Quote:
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The tough part is going out and buying the correct tool.
If you have your parts at a machine shop then an option is to have them do the measurements.

regarding Plastigage, the issue is less about reading the amount of squish but rather

a)holding rods steady while the bolts are torqued. It is really hard to avoid moving the rod and therefore likely affecting the squish of the plastigage

b)inaccuracy measuring all the main bearings at once. There is some tolerance on the alignments of the bearing bores, so the crank will sit on the two highest points and lift the other journals off the bearings, resulting in the plastigage being more compressed on those journals, giving a falsely tight reading. I noticed this and wound up testing it by doing two bearings at a time, with results closer to the measurements. Total P{ITA, thought, as the cases must be assembled/disassembled a lot.

Plastigage seems more accurate on the IM bearings, where there are only two on the shaft.
Clevite's plastigage instructions for doing an engine with individual main caps refers to not installing all the bearings but rather only two at a time to make sure it is accurate.
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Old 09-05-2018, 02:03 PM
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Has anyone thought of cutting down another engines bearings to fit. By that I mean narrow them to the correct width. There must be many other engines with the same diameter, clearance, and thickness.
Old 09-05-2018, 03:23 PM
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