Oversize bearing stamping

[Bobacuda]

I know pistons are stamped on top. Where are rod and mains stamped?

[JBNeal]

afaik, bearings are technically consumables so the packaging might be the only indicator of size as well as p#

[kencombs]

All that I've seen in the last 65 years of working on engines (yeah, I'm that old) have been printed, not stamped, on the back side.  Sometimes a base P/N followed by a - and numeric undersize print.  Sometimes just the undersize.   I have no idea what the print material is but it stands up to hot oil.

[Bobacuda]

Another quick thought 

 

A friend of mine recently rebuilt an old tractor engine that had been rebuilt once before in the ‘60s.  
 

He said the rod caps were stamped with the oversized bearing required.  That makes sense. Anyone else seen this?

[John-T-53]

I've seen what @kencombs has witnessed. Such as, ".010" printed on the shells.

 

I've never seen permanent markings on engine parts, besides the journal number, but if the crank has been ground it should have paint pen markings on one of the counter weights. Usually in the format of:

R 30

M 10

meaning, rods .030" undersize, mains .010" undersize. I'm not sure if this is standard industry markings, but each machinist has their own style. 

[Los_Control]

45 minutes ago, John-T-53 said:

but each machinist has their own style. 

I'm going to agree with this, I have a 1951 engine the crank is stamped 10/10 .... the bearings have no markings though.

[kencombs]

On 5/10/2024 at 3:43 PM, John-T-53 said:

I I'm not sure if this is standard industry markings, but each machinist has their own style. 

I don't think I've ever seen a crank that was machined for a customer(rather than for shop use) marked, other than a paper tag attached.   Big rebuilders always attach a metal tag to the block somewhere, usually riveted on.   On my current engine, it had no tag, no markings at all on the crank or block.   Pistons stamped .040, bearing shells marked on the back, .020, probably a rebuild in the past at an independent shop.   Like I've always done, tear down, measure, send crank and/or block to the machine shop, and probably two different shops.  Local guy did boring, cranks went to a bigger shop,  or just pick up and exchange crank at a local engine rebuilder.  I then picked up and assembled, usually after a hone in my place to my liking.  I usually did the valves but had the head surfaced at a machine shop.

Edited May 12 by kencombs

[Los_Control]

My engine does not have a tag riveted to it .... It is a 1951 Ford flathead .... makes no difference for this discussion.

 

On tear down the pistons were not stamped, so I assume they are stock bore.

Some valves had a makers mark  on the face of them while some did not .... I assume some were replaced.

The crank right on the front heavy weight, was stamped 10/10 .... In some fashion. I think it was 0.10 or something more technical .... But I knew it was telling me it had been turned on both mains & rods.....

 

It was stamped up on the flat part of the weight. You can see the flat spot of the weight in the photo, I was taking the photo to look at the journals.

I'm a bit concerned with the dark line in the center. The journals are totally smooth, you can not catch or feel anything with a fingernail. .... just discolored.

Perfectly understandable the way the main bearings are made ... I expect it.

 

 

Just do not understand it on the rod bearings.

 

 

 

 

 

Either way I think the engine can be cleaned up and put back together, except for the poor cam .... It is pretty dirty and hard to clean .... afraid it may need a new jr 400 race cam and adjustable lifters to match the new headers when put back together  

 

[Dave72dt]

Think about how many rods are place on that rod journal.  That's the transition line between the two rods.

[Merle Coggins]

I rebuilt a 383, from the family '70 Dodge Polara, in High School shop class. As far as we knew this engine had never been apart so we were surprised to find the rod journals 0.010" undersize. We then discovered a stamping in one of the counterweights "R010". We speculated that it was ground 0.010" under from the factory.  

[Los_Control]

3 hours ago, Merle Coggins said:

I rebuilt a 383, from the family '70 Dodge Polara, in High School shop class. As far as we knew this engine had never been apart so we were surprised to find the rod journals 0.010" undersize. We then discovered a stamping in one of the counterweights "R010". We speculated that it was ground 0.010" under from the factory.  

Ok so now 2 people has seen the crank stamped. ..... In my mind it would be much simpler to just stamp the crank then to stamp individual bearing caps?

 

I know nothing about the history of my motor, other than it was the kids Grandfather truck and was parked in the barn for decades. The fuel pump was missing.

Tear down & inspection, I just assume it has been rebuilt at some point because the bearings show zero wear and crank is stamped.

To be honest the stock cylinder bores match the bearings ..... Grandpa the owner was a farmer, maybe as his personal rig he rarely drove it .... except to church on Sundays?

[Matt Wilson]

Here's a photo of one of my bearing shells for a 25" engine (237/251/265 cid), with the oversize and other info stamped into the back.  The characters are impression-stamped into the surface.  There doesn't appear to be any raised material, but the characters are definitely stamped into the surface.  I can catch them with my finger nails.  These are new bearings (as of a few years ago), not NOS, that had Sealed Power on the boxes, and you can see F/m (I believe that's Federal Mogul) in the photo.  I think Federal Mogul owns Sealed Power.

Edited May 15 by Matt Wilson

[Los_Control]

13 hours ago, Matt Wilson said:

Here's a photo of one of my bearing shells for a 25" engine

I guess I'm just not familiar with the actual machinist process. ..... Good possibility I'm just lazy .... Lot of information on the cap .... I assume they have a stamp machine set up and all they really need to do is change the bearing size.

 

I did something similar when retreading truck tires, every Monday I needed to stamp out 200 aluminum date tags for DOT .... The stamp was all setup, just needed to change the week number. Insert blank tag and pull handle .... repeat 200 times.

I just assume they have a stamp machine like that for bearing shells ..... I also think if they were going to turn the crank they would do all journals the same.

 

It really would suck if each journal was a different size and required a different bearing size ..... So in my mind, I just think it would be easier to stamp the crank once then to stamp each cap ..... but what do I know

[kencombs]

2 hours ago, Los_Control said:

It really would suck if each journal was a different size and required a different bearing size ..... So in my mind, I just think it would be easier to stamp the crank once then to stamp each cap ..... but what do I know

I've never seen caps stamped, only bearings.   Cranks are usually only stamped if they are going into the company stock.  Customer supplied cranks,, drop-off and pickup may not be.   All that I've had done had a paper tag attached.   Machinists don't machine or stamp bearings, they just turn the crank and order, or remove from stock, the right size. I've never even bought bearings from a machinist, other than a big rebuilders that used to offer a package, cleaned and bored block with new cam bearings installed, crank, bearings, rings and pistons.  Good for me as no wait time for the work, they had the popular ones in stock.