MTFCA Forum

I have a 1914 engine that we are doing some repairs to. The crankshaft that was in the block is an EE shaft with some wear on the journals. I picked up a fresh ground shaft at .020 on the rods and mains. The shaft I replaced was also 20/20 but the rear journal was tapered so I went for the fresh ground shaft.

Here is the issue the EE shaft fit like it should in the bearings and had very acceptable end clearance's. The fresh ground shaft is .030 longer than the rear main web in the block. The shaft will not settle into the bearing saddles. The rear main shaft journal is .030 longer than the block web. This does not have anything to do with the thrust. The problem is the length of the rear main journal between the center main and the rear main journal. Both shafts are Ford script genuine parts.

Any thoughts??

frontyboy

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Made a mistake, correction, crankshaft journal is .030 shorter. NOT longer!!!! So the crankshaft will not fit into the rear main bearing journal. Crankshaft journal length is 3.097 and should be 3.125. This is a Ford script genuine shaft.

Has anyone had this issue before?

thnx
frontyboy

The bearings poured into the block must be ground to fit the crankshaft, or the crankshaft must be ground to fit the journals. Since the 3rd main adjusts the position of the crankshaft in the block, it is very possible that if you place in this position, all the rod journals would be off center too.
Have you measured the length of the crankshaft from the flange where the flywheel is bolted to the front of the shaft? They should be the same length. If so, it is the way the shaft has been ground. The EE shaft is made for the later engines, so if it fits in your car, the other one should fit too if it is ground correctly and the bearings are bored and faced correctly. I think you need to find a specialist who does bearings to fit it to the block.
Norm

How much shim will you have in the main bearing if you proceed down this path?
Perhaps install the crank in backwards (flange at the front) and see how everything fits.
If the fit is good and you will have some shims in each bearing, then probably worth proceeding.
If I was doing it I would set up my line boring equipment and trim the rear main to get a good location and clearance. Hopefully you have someone nearby that can do this job!

I don't think others are seeing your problem, first as you say, the length should be 3.125, 3-1/8". I can't see that crank ever coming out of a T block unless the bearing saddle had been shortened, I've seen them shortened before and babbitted to double the thrust area, which is one option for you, just shorten the block, or have the crank ground to lengthen the journal.

Best to have your revised problem of the cap being to long as opposed to being too short, it can be trimmed to fit your new crank.
Why the difference? Your old crank likely had a lot of wear & the grinder squared/cleaned it up. Motor was babbitted & machined to fit.
This is normal in a proper crank regrinding.

Everyone but Kerry needs to reread the entire thread and rethink/adjust their advice!

John, the way I read it, the cap is not the issue but crank to block.

Kerry wrote: ↑

Sat Feb 25, 2023 4:09 pm

John, the way I read it, the cap is not the issue but crank to block.

Now you got me thinking. Not a babbit expert, so I looked @ my 14 original motor currently scattered in the garage.
There is no Babbitt thrust surface in the block. The crank has about .030" play front to back.
All the thrust is in the cap which has only a few thousands movement.

Do current rebabbit jobs add thrust surface to the block?
That would be a reason the new crank couldnt be laid in the block since all Ford cranks started out the same length on the 3rd main.

To get a thrust surface on the rear main bearing in the block would require tinning the block. To do this, the whole block would need to be heated for the whitemetal to "take". In my experience, no T block has bearings tinned and poured in place. There are divots in the saddles into which the bearing material flows. These divots hold the bearing in place. The bearings should be peened once poured to seat then properly before being machined to size. The interface between bearing material and the cast iron block is mechanical, not a "soldered" joint.
If the cap is too wide to fit on the crankshaft journal, the thrust face can be machined back to fit. Clamp the cap and another donor onto a bar and turn back the needed one in a lathe. Or just have at it on an abrasive sheet on a face plate.

Hope this helps.
Allan from down under.

Abrasive material can embed in babbit and cause undue wear on the crankshaft. If you use abrasive to fit the babbit surface, it would be best to stop a few thousandths short of the final dimension and scrape the surface to a final fit.

You could clamp down, squared on a mill. Lathe would be best if you dont have the large facing tool rebabbiters use.
You could use a file also. Sandpaper would not be good due to loose abrasive bits embedding into the babbit.

Why on earth did anyone drift to the block having non-factory babbit and the block needs machining???

the man clearly stated that his crank shaft 3rd main is .030" narrower than stock:

Crankshaft journal length is 3.097 and should be 3.125. This is a Ford script genuine shaft.

he also stated that the engine was JUST torn down and a crank that was worn (but fit) was removed from the block. The block is not the issue.

I have never in my life seen a crankshaft made thusly, but it is one of only two facts to deal with: There was a 1914 engine that was going to receive some repairs and a crank that was previously in service was taken out of it, and secondly, another crank which is not dimensioned to FORD specs will not fit back into the previously serviceable block.

Perhaps I am alone in the universe with this opinion, but there is nothing to be gained by farting around with the block...the replacement crankshaft is wrong, being that it is .030" or so narrower at the 3rd main than the FORD drawing.

It's either not a FORD crank, or it was mis-manufactured and has never been in use since the day it was made.

Upshot: find another crank

Perhaps the out-of-spec crankshaft was spray welded, then ground to an odd size.

Well thats a possibility. A metal spray job has that look typically easily noticeable. At least everyone I have seen.
It has been thru a crank grinders hands. Perhaps a careful comparison of the 2 cranks side by side will show a built up flange.
If built up, it was built up a lot. not normal.

Its hard to believe a factory Ford crank so much narrower than normal/standard. I dont claim to know the factory spec, but the dimensions fit with my 14 motor.
OP claims both cranks to be Ford.
3.125 stock crank journal length sounds right. The 3.097 dimension for the block journal sounds right.
Is there some miscommunication in OP's terms?

Could the crank gone thru the manufacturing process & been so far from correct dimensionally, & used any way by a modification in the rear block & main cap machining? I assume the new crank came from another motor.

If I understand the problem as stated its a real head scratcher.

So my answer to the OP's question is no, never heard of such a situation.

Hi Dick,
Are you saying that the dimension from the rear of the #2 crank journal to the front of #3 crank journal is 0.030 longer than the space in the
block is? As in the rear half of the crank is to long for the block? I'm pretty sure I have a 20/20 crank unused in the box. If an other crank is
what you have to do.
Craig.

Further to some comments I will state that locally my T block babbit jobs have included the rear main thrust surface as part of the babbit in the block. No the block surface is not tinned, it is just held in place by the “pin holes “ in the block. They have stayed in place just fine!
I am not saying it’s “better “ just that it survives OK!
We have done LOTS of T blocks over the years.