Rear Main Melted Help

[allen]

Hi guys this is a long story but I will try and make it short had this motor done about 6 months ago.
Went and pick it up had the engine builder short block it in other words he set the crank and pistons and set the clearness anyway finish the motor install it with less than 200 miles it delvloped a wicked oil leak.
Removed the motor torn down the pan and found this was not the crank i set him. It was modified and the oil slinger was turn down and a rope seal install. The rope seal rip apart,
Took the crank out and had the slinger turn off and install synders new rear main seal for the first 500 miles everthing was great untill now.
Oil started pouring out again fed up was going to found a stock crank and turn it to macth the pour, after taking the motor out this what i found the thrust melted at the rear that a hunk of the bearing rip the new seal
motor was not run hard and ran very very good any ideas what did the thrust in and could it be turning down the slinger all the way thanks allen

when post pictures tonight

 

[Mike V. Florida]

To improve upon the Ford design, some rebuilders remove the slinger and use a "moden" seal. Other rebuilders now sell a kit to repair the first ones improvement.

My car has this "modern improvement" and leaks like a seive. Once my sons car is done I will have the time and space to tear into the engine and install the repair kit.

Will have to wait to see your pictures of your melted thrust. It had to have been caused by lack of lubrication but I would have thought that it would also have made a hell of a racket.

 

[BrianBurkert]

I HAD the modern improvement on my car. No good. Henry's way has worked for years.

 

[ivoryjohn]

See the post from 29ford roadster melting babbit part IIand his comments. I went to search for " rear main babbit melted" and got 29ford roadsters original post several months ago.

Seems he too replaced the transmission shaft along the way an the shaft was too long putting pressure on the rear main and causing in excess of .40 thrust and a melted rear main.

I'm not real sure about the fix they suggest.

Keep me posted and stay calm. This will all work out.

Your buddy, John

 

[Duffy1]

Folks ;

I have posted this before . When I bought my 31 sw with "B" engine ( 1,000 miles on rebuild ) it developed a severe rear main leak right after I got it home . Pulled the engine found a chevy rope seal had been put in between the slinger and the rear main seal . Also a plug had been put in behind the cam shaft . So what happened ? The rope seal had come apart and pieces of the seal had pulled the rear main oil passages . The cam had moved up against the plug and spun it tearing up the gasket . I removed all these "MODIFICATIONS " and put the engine back together like Henry had designed and had "ZERO " leaks . I am just glad the rebuilder left the slinger on the crankshaft . So if it does not leak as designed by Henry ,why do folks keep making these modifications ?

 

[columbiA]

The33"B" engine in my 30 coupe has never been totally rebuilt.I rebored it to .020" & replaced the timing gears,valves and lifters but its still running the original babbitt and after 13,000 miles it doesnt lose oil between 1,000 mile changes.If the brgs are fitted properly,the original slinger works just fine.

 

[dumb person]

So if it does not leak as designed by Henry ,why do folks keep making these modifications ?

Folks like to tinker i guess...

 

[James Rogers]

I have done engines both ways. Some done with the modern seal at the customer request, none by my choice except one insert engine that is my own. I prefer the original way with babbitt and the slinger but do it like the customer wants. I just don't warranty the ones modified at the customer request. I don't care for the seal mod. There are some engines that have to be modified for the modern seal because the slinger is cut for the rope seal which, is no longer available. Feld Pro has discontinued the manufacture of this seal and has a neoprene seal as it's replacement that won't work in the modified Model A.

 

[allen]

I havent put a picture on the fordbarn in a while has this changed, I used to hit insert picutre and download from there. keeps asking for a url. long time ago I used photo shop or something like that do I need to re sign up with them, trying to post the rear main cap

 

[allen]

more pictures

 

[BrianBurkert]

My limited experience with rear main leaks on new engines is oil somehow getting through between the edge of the shim and the crank. If the shims are crooked and aren't square up against the crank, they can leave a passage for excess oil to get by.

 

[allen]

My limited experience with rear main leaks on new engines is oil somehow getting through between the edge of the shim and the crank. If the shims are crooked and aren't square up against the crank, they can leave a passage for excess oil to get by.

thanks for the reply brian, if you look close you can see the melted bearing over the return hole so yes this will pour, need to know how the thrust melted

 

[Kurt in NJ]

Lack of oil groove from oil supply hole limited oil in the bearing, not enough oil to make it's way to rear thrust ----is that a blob of brass on the corner on the block??

 

[allen]

Lack of oil groove from oil supply hole limited oil in the bearing, not enough oil to make it's way to rear thrust ----is that a blob of brass on the corner on the block??

thanks Kurt I think your looking at the shims in the corner, wondering if the new seal crushed over the oil hole i see no sign of this because the seal still has its shape, no doubt it got hot, when Assembly this nothing was tight if fact i thought it might have been too loose, did not check the clearness because it had less than 500 miles since the builder built it

 

[Marco Tahtaras]

The point Kurt was making is that your babbitt lacks the typical oil groove or passage which disburses the oil across the bearing. All you have are the wells along the parting line in the block which in my opinion is insufficient to circulate the oil in a non-pressure system.

 

[Kohnke Rebabbitting]

Hi guys this is a long story but I will try and make it short had this motor done about 6 months ago.
Went and pick it up had the engine builder short block it in other words he set the crank and pistons and set the clearness anyway finish the motor install it with less than 200 miles it delvloped a wicked oil leak.
Removed the motor torn down the pan and found this was not the crank i set him. It was modified and the oil slinger was turn down and a rope seal install. The rope seal rip apart,
Took the crank out and had the slinger turn off and install synders new rear main seal for the first 500 miles everthing was great untill now.
Oil started pouring out again fed up was going to found a stock crank and turn it to macth the pour, after taking the motor out this what i found the thrust melted at the rear that a hunk of the bearing rip the new seal
motor was not run hard and ran very very good any ideas what did the thrust in and could it be turning down the slinger all the way thanks allen

when post pictures tonight

Allen, it is clearly your Rebabbitter's, jobs fault, or more accurate to say , you never got a Babbitt Job. If you have him do it over, DO not expect a different out come!

1.== The Babbitt in the block is clearly, not peened! Look at the gap between babbitt, and the block, it should be tight!

2== No oil wells on the cap, and not correctly made on the Block.

3.==They have NO wiper, on spreader grooves in, cap, or block, to connect the oil wells, if they had any!

4.== Look at the Babbitt finish, and see the harmonic marks from the dull tool Align Bore Bit that was used. The marks in them selves, may, or may not hurt the running, is every thing else was right, BUT, when the cutter is dull, the Align is not cutting a perfect Aligned Bore!!! The dull bit is acting like a Sled Runner

5.==If you look at the rear Main cap, towards the back end, ahead of the melted thrust, you will see a different coloured, maybe a 3/8 size, round mark, to me it looks like there was a hole drilled under there, years ago, to try to fix an oil fix, which don't work, by the way!!! I am thinking the Babbitt guy put some babbitt puddy, in the hole, so he could get the cap poured, rather then fixing it right. Now with the puddy gone, the Babbitt is just hanging out there in mid air, with no backing, an will sooner, or later break up, and take the rear main, anyway!!!

6.== The last, and more important thing hear is, the Babbitt used here is lead Babbitt, NO GOOD!! You can tell by the color!!

I will show the Contrast, Good Luck Allen, Herm.

 

[George Miller]

Very poor Babbitt job, along with what Herm said the Babbitt was bored bigger than the crank. It is only hitting the crank in one small spot. Why not send it to Herm and get done right. That would be the last time you would ever need it done.

 

[Kohnke Rebabbitting]

Very poor Babbitt job, along with what Herm said the Babbitt was bored bigger than the crank. It is only hitting the crank in one small spot. Why not send it to Herm and get done right. That would be the last time you would ever need it done.

Dang, I missed that one George, you are right as Rain, the crank is riding low in the bearing, away from the part lines!!

 

[James Rogers]

Looks like the bore was several thou too big and the shims were removed to get the clearance. That let the top and bottom clearance correctly but the sides not. Only a small spot was within clearance at the crest of the bearing.

To be able to use a rope seal the slinger is not cut completely off but, is cut to the same height as the thrust ring. This leaves a ring to embed into the rope and create a dam to stop oil. It works sometimes and, sometimes not. When the ring is cut completely off the only seal that will work is the Burtz seal or the seal Ed Barnett sells through Snyders and others. The cork seal (which is the one you used) in my opinion is the best remedy to a slinger that is cut completely off.

Not having wells and the distribution grooves is exactly why your babbitt failed. Lack of oil is why the babbitt melted. Probably the only reason it lasted as long as it did, is because the cut was big enough it got some oil around the side of the crank but, that engine was doomed to failure from the beginning.

 

[columbiA]

I would rather build up an engine with good old babbitt than have one redone today.I have built up numerous angines that way & they have turned out well with no great expence.If old babbitt has stood up well,then it should be good for many more miles.I think a new babbitt job is a pig in a poke as far as Im concerned.I think the reason is because most of the old masters of babbitting have died off Also a good reason so many are going to inserts.A good babbitt job will last an amazingly long time.I see no reason for a rear seal as the slinger will work just fine