How does one pour rear main bearing caps?

dumb person

dumb person

Well-known member
While reading on the subject of pouring babbitt bearings i noticed that there was no reference to the ballcap, the '4th main'. While it was told of the importance of peining the hot metal into the block, there was no explanation of how it was done, at least not a visual one. So how would a 4th main ballcap be peined, if at all?
According to http://www.mtfca.com/discus/messages/257047/258499.html?1325990596 that thread, cleaning of the metal with a wire brush will not work, tinning is a secret and so is peening the metal. i figure peening is a word with different spelling in different nations.

i am curious to know how it is actually performed.
 
I've seen pictures of a KR Wilson babbitt peening tool for Model As. I imagine the Ts was similar. The tool looks like a mallet, with the handle and head made of steel. The head is cylindrical, and the diameter is the same as the rough poured babbit. There is a pattern on the head, like a cross hatch or striations. My guess is that you wait until the babbitt has "set" somewhat, and while it is still warm, you put the head of the tool in the cavity, and whack the handle a few times to make sure he babbit adheres to the block.
 
Would the peining be done to keep the cooling metal from shrinking away from the block? Wayno
 
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Yes that is why peening is done. The 4th main is just pored and bored to the size needed. It's pressed steel unlike the cast steel caps and cast iron block. Generally only the block is peened. The caps usually use a bonding paste that is melted onto the surface so the babbitt adheres to them.
 
You don't have to peen the fourth main bearing because the shell is steel and can be tinned, and thus the bearing bonded to the cap, same as the rods and caps, if it is done right. Only the iron blocks are peened.
 
Ben I have these reamers for main bearings .Ted
 

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So i see some surface rust upon the bearing surface where the old white metal is lifting away. What is a good recommended method of removing this rust? i also have no access to a prepared tinning paste. Would a soldering flux do? Or would a flux like hydrochloric zinc risk rust under the surface of the babbitt?
 
Funny...In the 1960's war movie.. "The Train" with Burt Lancaster..
He fixes locomotive drive rod bearing by pouring a babbit bearing..
 
In war you do what will keep you alive. I think it was a passage in the "Grapes Of Wrath" where a migrant was going to limp along after repairing a burnt out bearing with a section of bacon rind. I talked to a fellow at a old motor show/steam-up that said his running stationary engine had J-B Weld as the crank bearing and hadn't had trouble as of then. The motor was running on as we talked.

Maybe this rig has bacon bearings! It at least made it to the old grocery store.
 

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J Franklin said:
In war you do what will keep you alive. I think it was a passage in the "Grapes Of Wrath" where a migrant was going to limp along after repairing a burnt out bearing with a section of bacon rind. I talked to a fellow at a old motor show/steam-up that said his running stationary engine had J-B Weld as the crank bearing and hadn't had trouble as of then. The motor was running on as we talked.

Maybe this rig has bacon bearings! It at least made it to the old grocery store.
Click to expand...

Funny stuff!!!
When I first got my car the Timing gear broke and I had to replace it.
I had never done anything like that. And someone on the Board encouraged me and said...Farmers have been fixing these cars for years..During the depression., no one had money to take them to mechanics.
It was great encouragement!
 
http://viczannis.com/5915.html This is the book to get if you want to know about babbitt and Model A's best 29.00 I ever spent. Use a ball peen hammer hit every square inch of babbitt while it's hot. You can engrave a little pony into the ball if you want to leave little ponies across your bearings which will be all be removed by line boring and finishing. He describes the radius on the bearings as well as 45 off that ridge which will leave a groove reservoir of oil where caps mate. He describes hand turn crank with journals coated with prussian blue to find high spots he finishes with 1200 sandpaper to mirror finish. I had always heard bearings were a craft but it looked dead simple to me, (this worried me because I'm older), now I know what they are talking about.
 
hale1776 said:
http://viczannis.com/5915.html This is the book to get if you want to know about babbitt and Model A's best 29.00 I ever spent. Use a ball peen hammer hit every square inch of babbitt while it's hot. You can engrave a little pony into the ball if you want to leave little ponies across your bearings which will be all be removed by line boring and finishing. He describes the radius on the bearings as well as 45 off that ridge which will leave a groove reservoir of oil where caps mate. He describes hand turn crank with journals coated with prussian blue to find high spots he finishes with 1200 sandpaper to mirror finish. I had always heard bearings were a craft but it looked dead simple to me, (this worried me because I'm older), now I know what they are talking about.
Click to expand...

Fantastic... Sounds like a great book...As far as the Babbit goes this Can be applied to most early fords, right. I know the dimensions would be different, but the basic principles apply.
Did you actually do your own babbits?
 
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