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New or NOS


Matt Wilson

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Hi guys,

 

When considering the purchase of crankshaft bearings for a flathead six, I have the option to purchase new Sealed Power parts or NOS Mopar parts.  Sealed Power makes very good products, I believe.  Mopar also made very good parts for our engines, but of course, those parts don't have the benefit of any new technology or manufacturing improvements that may have come about in the last 60 or more years.  Plus, they've been sitting on a shelf for that long.  I doubt sitting on a shelf has hurt them, as long as they were packaged well and haven't been exposed in some way to a harmful environment, but I can't be sure.

 

I guess bottom line is, what's everyone's views on whether to buy new or NOS crankshaft bearings for an engine that will get used a lot, and will have some extra power running through it by way of dual carbs, headers, upgraded cam, increased compression (8:1) and electronic ignition?  The NOS bearings are certainly MUCH less expensive than the new ones (less than half the price of new), but maybe there's some benefit to having the new parts (you get what you pay for)?  On the other hand, I'm sure some folks will argue that NOS parts are better than what you can buy today.

 

Mainly, I want to be sure that if I buy NOS, I won't be sacrificing durability because I wanted to save money up front on my parts purchase.

 

Thanks all!

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I have opened a many boxes when I worked for Ford, what was stamped on the part....???   TRW, Cleveite 77 etc...many OEM is just another name on the box...ask anyone anything and expect about any answer...for me, metallurgy has come a long way in the past 70+ years...most folks should have an idea of what is or is not quality.  

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16 minutes ago, DrDoctor said:

Matt,

   If the main journals, or the rod journals, of your current crankshaft have been machined, the respective NOS bearings won’t be the proper size. My recommendation's to purchase the Sealed Power bearings in the size you need for the respective journals involved.

I would buy NOS undersize bearings, to match my crank journals, if I decided to go the NOS route.

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21 minutes ago, Plymouthy Adams said:

I have opened a many boxes when I worked for Ford, what was stamped on the part....???   TRW, Cleveite 77 etc...many OEM is just another name on the box...ask anyone anything and expect about any answer...for me, metallurgy has come a long way in the past 70+ years...most folks should have an idea of what is or is not quality.  

It is indeed possible (actually quite likely) that one of those companies made the parts for Chrysler.  I think I was told once that the OEM bearings were Clevite 77.  I suppose that's beside my point.  My main point is to find out out whether anyone knows what improvements, if any, have been made to the parts we would purchase new nowadays over the NOS parts that were made 60 years ago (or more), or if sitting on a shelf could somehow degrade them (I doubt it, but this is a forum for asking questions).  

 

I know for a fact that bearings in general have improved substantially, but the question is....have those types of improvements been incorporated into the new bearings we can purchase today for these engines that were built decades ago, or are they still being made using similar technology to what was used back then, or at least a modern equivalent because it might be cheaper than using newer technologies and that's all that is required for the application, or maybe even because it's somehow more compatible to the application. 

 

Kind of an open-ended question, I realize, but someone may know the answers....or someone may not.  Perhaps someone will even chime in and say they bought NOS bearings 15 years ago, with packaging from 1948, and they have put 50,000 miles on the car with no trouble since then.  These are some the types of answers that might prove most useful, but I'm looking for any input.  It could be that no one will chime in with that type of info, but....I figure I will never get the answer if I don't ask.  Do I expect to get a broad spectrum of answers that vary as much as the people who provide the answers?  Yeah, probably so, but that's ok.  I still want to hear them.

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The machine shop should take the new main and rod bearings.... fit them into the block and big end of the rods...

Bolt up and torque the main bolts/rod nuts...

Then measure and check the new bearing bore diameters for accuracy and actual diameter.....then the machinist can grind the crank to the new bearing sizes for specified clearance.

Never trust what the box the bearings came in says as for size......

Once the crank is is finished again more measuring....

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12 hours ago, Dodgeb4ya said:

The machine shop should take the new main and rod bearings.... fit them into the block and big end of the rods...

Bolt up and torque the main bolts/rod nuts...

Then measure and check the new bearing bore diameters for accuracy and actual diameter.....then the machinist can grind the crank to the new bearing sizes for specified clearance.

Never trust what the box the bearings came in says as for size......

Once the crank is is finished again more measuring....

Yes, good point.  Oddly, both machine shops I talked to yesterday said this was not necessary and that I could just bring in the crank and tell the what undersize I'm planning to use.  Makes me wonder a little.

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what is to wonder....with the correct bearing cap in the correct place...odds of shift is very little.  Machined tolerances are  just that....stock should have been checked and verified by them to ensure no line bore has been done and if so, again, that done back to proper specs...the crank is x undersized and the bearings should be correct if the grinder actually achieved the target tolerance on the crank...I am thinking a caliper may need be calibrated....dropped one time too many

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3 hours ago, Plymouthy Adams said:

what is to wonder....with the correct bearing cap in the correct place...odds of shift is very little.  Machined tolerances are  just that....stock should have been checked and verified by them to ensure no line bore has been done and if so, again, that done back to proper specs...the crank is x undersized and the bearings should be correct if the grinder actually achieved the target tolerance on the crank...I am thinking a caliper may need be calibrated....dropped one time too many

The wonder is that I had another machine shop tell me, a while back, that the main bearings should be installed in the block, main caps torqued down, inside diameters measured, all before getting the crank ground, and I recently read the same thing in an online article written by a pro who seemed to know what he was talking about.  Neither one of them explained why.  Yet that same machine shop said it was not necessary for rod bearings.  So it made me wonder when I asked two shops yesterday, and they said it was not necessary.  In theory, it seems like you shouldn't have to do this, but in reality, I guess some folks must have some reason for it.  At the very least, I'll measure the bearing inner diameters myself, just to be sure nothing looks out of whack.

 

Thinking about it some more, I wonder if the reason for doing this on the mains is to check for issues with the main bores, as it is not always a standard thing to correct those bores, while it is pretty much standard to correct rod bores during rework of the rods.

Edited by Matt Wilson
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The babbitt-layered design of old Mopar bearing shells is by no means obsolete. Such bearings are still produced nowadays, alongside with other designs, particularly aluminum-silicon- and aluminum-tin-layered bearings. Babbitt has its advantages and disadvantages compared to aluminum, as described here:

Bearing materials

Particularly, babbitt has superior capacity to hold oil on its surface, and superior resistance to galling. On the downside, the babbit layer must be very thin, and once this layer is worn down, all the advantages are gone.

I don't see any reason why NOS bearing shells from reputable manufacturers should be inferior to today's shells

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to clarify my input a bit more...in no matter was I saying it is inferior.....but for the price of OTC verse NOS where the NOS usually (not always) commands a higher price just because it is NOS...this was basically my gist of the situation....but in many other areas, advancements in engineering and production do have benefits.

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On 1/30/2019 at 4:03 PM, sser2 said:

The babbitt-layered design of old Mopar bearing shells is by no means obsolete. Such bearings are still produced nowadays, alongside with other designs, particularly aluminum-silicon- and aluminum-tin-layered bearings. Babbitt has its advantages and disadvantages compared to aluminum, as described here:

Bearing materials

Particularly, babbitt has superior capacity to hold oil on its surface, and superior resistance to galling. On the downside, the babbit layer must be very thin, and once this layer is worn down, all the advantages are gone.

I don't see any reason why NOS bearing shells from reputable manufacturers should be inferior to today's shells

Thanks for the input.  I'll check out the link you posted.  Maybe I will ask Sealed Power what their new bearings are made of....maybe they're still babbit.  I find it interesting, if nothing else, to know that kind of stuff.

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On 1/30/2019 at 4:36 PM, Plymouthy Adams said:

to clarify my input a bit more...in no matter was I saying it is inferior.....but for the price of OTC verse NOS where the NOS usually (not always) commands a higher price just because it is NOS...this was basically my gist of the situation....but in many other areas, advancements in engineering and production do have benefits.

I agree.  In this case, however, the NOS parts are MUCH cheaper than the new parts...meaning less than half the cost of new.  So along the lines of the old adage, "you get what you pay for," I figured I'd ask if there's any significant downside to buying NOS.  I doubt there is, but not being a guy who knows everything, I thought it prudent to solicit input.

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I've wondered already about the bearings in the starter & generator, if rebuilding anyway, what is the opinion on sealed bearings vs the original type, which require regular maintenance.  I have always been one to look down on sealed bearings, thinking of them as "planned obsolescence" parts - stuff they made impossible (or very difficult) to maintain (so that they can sell you another one sooner, rather than later).  But I'm willing to be corrected.  I also imagine, however, that the maintenance intervals for those bearings was more frequent then than would be necessary now, unless you also drive on a lot of dusty roads, as was much more common back then.

Edited by Eneto-55
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the sealed bearing for the generator is really over kill on the design and has played immensely into the long life these unit have already enjoyed and STILL continue to serve the owner many decades down the road.  The opposite end of generator and use in the starter at all points with the bushing that do wear over time but at such a low cost to replace when servicing brushes etc that even at that the life, reliability and low cost make them more than a very good overall design.  With the constant side pull  of the generator, a bearing is needed else you would be constantly servicing bushings.  IF the bearing was not sealed, you would have grease slung willy nilly into the unit itself.  

Edited by Plymouthy Adams
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