Babbit Bearing Questions

A thought on adjusting babbit bearings by 'feel' or shim stock: Since you will be dealing with a worn engine, the crankshaft journals may be a thousandth or two out of round (maybe more!). If you happen to have the crank positioned so that you're setting the 'feel' on the worn spot on the crank, it will bind when the crank is rotated to the unworn part of the journal. So make rotating the crank part of the process on an on old, worn engine. Or mike the rod journals to know for sure. You will find the low spot, if any, is almost always in the same place-the point of highest cylinder pressure-maybe 15-20 deg. past TDC, if I remember.
Also, if you have .002" clearance on the good part of the crank, you may have .004" or .005" on the worn or "flat spot". Thus the chance for a knock.
 
Hi 40,

As you correctly state, when the journal is out of round, the rules of bearing adjustment are in a totally different court; and unless addressing same when found, it is just a matter of time for failure.

Ford also addressed this out of round in his Model T Manuals .... but by the time Model A's came out, appears that because to many mechanics, it was already "old hat", Babbitt bearing adjustments were not overly emphasized during the later Model A era.
 
H. L. Chauvin said:
There was no aluminum foil in the old days either ...... when millions upon millions of Babbitt bearings on steam and gasoline engines were correctly and successfully fitted by "feel".

No doubt Plastigage probably came out after humans lost their "feelings". LOL
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I have used 'roll-your-own' cigarette paper to check bearing clearance in my bad old smoking days.

If you must mess with the end caps, use method in post #10.
 
Hi Ian,

Ford also addressed filing the connecting rod end caps in the 1909-1927 Model T Manual in paragraphs 384 & 385 if anyone is interested in reading same, along with his photos in figures 232 & 233.

All of this was done at a time when carpenters were still capable of building perfect mortise and tendon wood window sashes to match existing sashes on the jobsite as opposed to having an all thumbs carpenter today installing a prefabricated aluminum window out of plumb.

If one goes to a wedding today, one does not know "who" signed the guest roster ..... judging from signatures, appears today's generation cannot feel the pen in their hands let alone feeling Babbitt bearing movement.

It is difficult for many to imagine today that fine precise watch springs and very intricate watch parts were once made by simple humans by shaping metal with non-electric hand tools.
 
Yes people today would not believe how I adjusted many bearings in my Dads garage. Still do it that way today. It is not with tin foil.
 
Hi George,

Most interesting, in looking back today, was when I watched my Uncle install a new head gasket on my Model A over 50 years ago and tighten the head bolts "without" a torque wrench in sight ....... where I never had the head gasket leak.

Neither he nor my Dad ever owned a torque wrench. If they were living today they would be 110 and 113 years old.

Also, ever notice in photos of Model T Ford assembly plants, the lack of torque wrenches ..... everything was "feel".

If a guy was all thumbs and could not chew gum and blink, after breaking a few head studs without a torque wrench, managers could slide him over to the inner tubes installation department where he could keep his job and work his way back up.
 
After having my engine rebuilt, it developed a new knock....Checked and rechecked to find the timing gear bearing and some teeth chewed off. Some real scared moments. All is A OK now.
 
Vermins' bone stock engine, built in '87 & has "maybe" 40 miles on it. In the rest of my lifetime I don't anticipate ever having to adjust the bearings, I run good oil & he has an air filter. If you'll be looking for a GOOD car, in a few years, keep me in mind.
Old Bill W.
 
BILL WILLIAMSON said:
Vermins' bone stock engine, built in '87 & has "maybe" 40 miles on it. In the rest of my lifetime I don't anticipate ever having to adjust the bearings, I run good oil & he has an air filter. If you'll be looking for a GOOD car, in a few years, keep me in mind.
Old Bill W.
Click to expand...

SAY WHAT:confused:
 
Just in case anyone is interested in learning various recommended methods for adjusting vintage Babbitt bearings, received this from a vintage car friend.

This recommended method is very similar to that recommended by Ford in his 1909-1927 Chapter V of his Model T manual and recommended by other car manufacturers of yesteryear:

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"I would think the issue here, however, is that to use plastigage for a bearing not freshly machined isn’t a good idea.

The slightest “out-of-roundness” can bring about a false reading.

The Trial & Error method, on the other hand, is foolproof in this case, and will work equally well with newly machine bearings. Specifically - - -

TRIAL & ERROR METHOD -- During reassembly, adjust connecting rod bearing running clearance to a value from 0.001 to 0.003 inch.

Adjustment is by use of shims in attaching connecting rods to the crankshaft.

Remove all the shims (one rod at a time) and measure the top and bottom stacks with a micrometer to ensure they are equal to start with.

The thin shims are 0.003 inch thick. Install connecting rod with shim stacks and torque.

If there is no binding or halting in crank rotation, remove 1 shim (top and bottom) and repeat until binding occurs.

If there is binding, add 1 shim (top and bottom) and repeat.

If it spins freely, you are good to go! NOTE: This trial and error series is much easier to perform “on the bench”, prior to installing the crankshaft and the rod & pistons units into the main case."
 
Even though the dealers had a lots of experience in adjusting by "feel", it all relied on the skill of the individual mechanic, who "maybe" should be workin' in the FLAT TIRE DEPT. or CLEANING THE OUTHOUSE.
Bill W.
 
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