Forensic ongoing - failing rod bearing

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Model T Ford Forum: Forum 2015: Forensic ongoing - failing rod bearing
Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Saturday, October 31, 2015 - 03:01 pm:

As I have mentioned in another thread, my newly acquired Model T Pick-up blow a rod bearing crossing a highway bridge.
When I took of the inspection lid, this was what I found:

It was obvious that the bearing got overheated as I felt a drag a minute before the bearing collapsed, but I would have expected melted babbit - not babbitt "powder".
Now I have read a little about babbitt failures and it looks like a fatigue failure and as the fatigue strength drops as the temperature goues up - that makes sense.
The reason I ask is, that the car have been standing for 20+ years and even though I have of course swapped oil a couple of times since I started driving it, I wonder if the other 3 will go soon or this bearing just was a little tighter than the others and when the lubrication was less due to the upward drive of the ramp to the bridge (several miles), this was the one to collapse.
I do not have in plan to do a complete overhaul as this winters project is my other T.
What do you think?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Garrison - Rice Minnesota on Saturday, October 31, 2015 - 03:29 pm:

Hi Michael. That looks pretty rough. Are you going to have to pull the crank to have it reground? It seems if the Babbitt went there's a pretty good chance the crank journal went too. Also if Babbitt was bad on one Rod, wouldn't you expect to inspect the Babbitt and clearances on the rest? Maybe you could get away replacing the bad rod and cap but as long as you've got that inspection pan off, why not at least look at the others?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Saturday, October 31, 2015 - 09:47 pm:

If its rod #1 you have an oiling problem, likely a stopped up oils line.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tony Bowker, Ramona, CA on Sunday, November 01, 2015 - 01:37 am:

I agree that the bearing did not melt, rather the babbitt broke up into dust. That is similar to the problem with babbitt in the rear axle. I suspect it is caused by the lack of oil over a long period of time, even if the item is not stressed. If this is the case, I would guess all seven bearings could suffer similar fates.....


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Sunday, November 01, 2015 - 01:53 am:

Plan is of course to inspect all bearings to the extent possible. I know that I cant get to the rear main bearing.
I hope not to have to reground the crank. As a matter of fact, I have another slightly later block (July 1. 1925). which have the bosses that match the hogshead, that are 26-27 type. If I have to go down that route, I'd rather make the later block.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Sunday, November 01, 2015 - 05:28 am:

Bearing #3 (OK) and #2 (failing) now disassembled:

and here the rod part of the bearing:

I will look on the surface of #3 (and the other bearings as they come of) under my microscope for cracks, but to my naked eye, #3 looks like an ordinary rod bearing with some wear.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Sunday, November 01, 2015 - 07:00 am:

Was it #1 that failed? Remember to blow the internal oil pipe clean with compressed air (can be reached from the inspection pan) - and I would have added an accessory external pipe too :-)

Pull all the rods, have the bad ones rebabbitted and compare weights - they should weigh about the same in both ends - and total, can be lots of work to get a set that's about the same without having to grind off all the strength from the heavy ones - best to have a few to choose from.

Have you miked around the crank journals? If any of them are oval you may have to regrind the crank, babbitt adjustments won't last.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Sunday, November 01, 2015 - 07:05 am:

It's possible someone used the wrong type of babbitt in the failed rod sometime back in the day? Lead babbitt is used in low speed applications but will break in car engines - Ford Babbitt didn't have any lead - except for the infamous rear axle thrust washers.

(Message edited by Roger K on November 01, 2015)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Sunday, November 01, 2015 - 10:23 am:

No Roger, it was #2.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Sunday, November 01, 2015 - 11:02 am:

That's close enough to the front to suspect not enough oil from the internal pipe..


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Eubanks, Powell, TN on Monday, November 02, 2015 - 08:13 am:

I had the same thing happen on a tour in NC. The babbit just blew up into small particles and it was not caused by lack of oil. I have very large external line as well as the std interior oil line. Replaced the rod and car is doing well after several miles of running. My opinion is that the babbit was bad.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Monday, November 02, 2015 - 10:53 am:

It is possible that if you had a very loose bearing, that the constant knocking could cause the babbit to crack. Usually it is caused by either very poor babbit or a poor job when pouring the babbit.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Monday, November 02, 2015 - 02:46 pm:

Engine ran smooth before. No knocking at all, but given that it have cast iron pistons, no dippers and hole for oil and no external oil line and I was driving 35 mph up of a 3 miles long ramp might have stressed the engine more than good.
There is a good chance the engine is relatively low milage engine and hence original Ford babbitt bearings in the rod. Which of course mean 90 years of age......
(Pistons is STD I think)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Monday, November 02, 2015 - 03:07 pm:

Dippers or extra oil holes in the rods are not needed given Dean Yoder's experiences driving thousands of miles all over the US at 55 mph with a trailer - without any x groove or other modifications of the rods. (but I think he has an accessory oil line :-) )

Who knows what was done in the 60's when your new pickup was rebuilt, or maybe some rods has been changed over the 40 years before that?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Monday, November 02, 2015 - 03:55 pm:

The guy that made it in '63 died last year, but I'm privileged to know a couple of guys that knew him as well and which may know what have happened to the car. The current engine was put in the car to replace what was in it (probably more true to look like a 1919) and it was supposed to be a good engine. I had 4 new 0.030 OS pistons on the shelf and they where way to big for the cylinders, so I believe them to be STD.
I will borrow some micrometer gauges and measure both journals and pistons, but would not be surprised if the are all standard.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Bender Tulsa Oklahoma on Monday, November 02, 2015 - 04:40 pm:

FYI. Babbitt will melt at 425 degrees apx. The engine never would have gotten that hot. The drag you felt was more than likely when the Babbitt gave way. Your Babbitt just gave up. One reason could be a bad tin job, but from the pictures I can't tell.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting, Clare, Iowa on Monday, November 02, 2015 - 10:12 pm:

Michael, could you take some pictures of the rest of the bearings?

Herm.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Monday, November 02, 2015 - 11:45 pm:

I will as soon as I get them off the car. And the journals as well.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Sunday, November 08, 2015 - 11:24 am:

Here is rod #1:

Picture taken after I drilled the new hole in the cab for better lubrication and for the dippers.
As you see - nothing but expectable wear.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Dewey, N. California on Sunday, November 08, 2015 - 12:49 pm:

Hmm, don't believe us when we say dippers & holes aren't necessary, eh?
expectable wear? Hmm, so far I see shiny spots in both rods, and the rest of the bearing surface looks a little dull and not smooth. Better check your crankshaft, it may at least need polishing. I would also, while they are out, have the rods checked for being straight & true; this is a very important step that, for some reason, many folks fail to do.
Of course, all of the above is just IMHO, and is probably only worth what you paid for it!!
:-)
OH, and I don't think the cast iron pistons have anything to do with the bearing failure nor "increased stress", but again IMHO only!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Saturday, November 21, 2015 - 03:03 am:

Just to finish this thread - I managed to find a rod that could be fitted and the car runs OK now and just in time to participate in the opening of the Hans Christian Andersen Christmas Market in the Coal Market Square in the old center of Copenhagen.
Now I know what is the project next year - the "triplet" engine from July 1st 1925 must be rebuild for this car. Anybody have a EE crank? :-)

(It's a buddy driving - Photo: Martin Arli)


Top of pagePrevious messageNext messageBottom of page Link to this message  By John T. Tannehill III, Hot Coffee, MS on Saturday, November 21, 2015 - 05:17 am:

Michael I enlarged the picture of the remaining babbitt and when you supersize it some of the larger chunks looks as if there was significant porosity in the Babbitt, Something I learned about reading some threads with Herms comments and then experiencing it when pouring Babbitt.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Eubanks, Powell, TN on Saturday, November 21, 2015 - 09:01 am:

I lost the babbit in one rod, replaced it with a 60 year old rod & babbit then lost the thrust sides of another rod this month. I am changing all four rods now. Satisfied it was a bad babbit job as the first one exploded like the pics above.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Saturday, November 21, 2015 - 11:34 am:

#1. The babbitt in the surviving rods shown in the photos is not a "Ford Factory" babbitt job. Note that the "radius" for the crank journal fillets is simply a 45 degree angle and NOT a radius as Ford would have done. Also, the oil groves at the parting surfaces of rod/cap are not "Ford". That being said, there should be nothing incorrect enough in the "radius" or "oil grooves" of those rods all by themselves to burn out those bearings.

#2. Your photo of the failed bearing is a "textbook" example of a "burned out" bearing. Bearings burn out for a variety of reasons. Lack of lubrication, too tight of a clearance, too loose of a clearance (either too tight or too loose will not allow a strong enough oil film to form). When a bearing burns out it typically melts and re-solidifies almost instantly. Many times you can even see a hairline of molten babbitt slung around the interior of the crankcase directly in line with the edges of the bearing surface of the rod.

#3. If you were going 35 MPH "up a ramp" for 3 miles before it happened, then you were "lugging" the engine at that point... Which is putting a MAXIMUM amount of stress on the internal engine parts. (If anything was far enough out of spec to fail that would be the time it would fail.)

#4. Sounds like the engine was out of service for 20 years then was put back into service with a couple oil changes... This engine was pretty much "an unknown quantity"... Anything that had been done to it, or whether it was or was not "properly" rebuilt at some point in the past sounds like it would be a matter of speculation at best. In other words, it would be relatively impossible to determine exactly why something failed unless you knew exactly what the surface finishes, dimensions, clearances, babbitt mix, etc would have been BEFORE the failure.

In regards to any used or rebuilt engine/transmission that does not have proper written records, documentation, or invoices stating exactly what has been done to it and WHO has done it, you really have to assume the worst case scenario. Your insurance against failures is pretty much to disassemble, clean, and inspect at the very least... pull the hogshead, pan, check all clearances & fits, make sure the entire assembly is SURGICALLY CLEAN inside, re-gasket and reassemble BEFORE USING.

I terms of what I see in your photos; It IS a burnt out rod bearing. Buy the Model T Ford Club of America books "The Engine" and "The Transmission". Pull your motor, put it on the stand, mic the bearings and if they meet specs in the book, order a set of rods, install & adjust them properly, check everything else inside the engine and trans (as described in the books).


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann, Blistrup, Denmark on Saturday, November 21, 2015 - 02:27 pm:

Thank you for your analysis.
As I state in my last post, I have a late 1925 block with bosses on the rear of the cylinders, which will fit with the >1925 transmission to a totally rebuild drivetrain for a lasting solution.
I have the books.


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