Crank Pulley Damaged - Rebuild or Diesel Swap?

[FJHokie]

Sadly, I have a damaged crank shaft and the harmonic stabilizer won't sit firmly, I have previously had it welded in place but it cracked in the recent old weather. So.....

I either have to pull the engine and get it rebuilt ($2.5k) or put in a Diesel (Cummins 4BT - $5-6k?).

What do you guys think?

Pros and Cons of Diesel and what are the typical costs?

 

[ad20k]

Just out of curiosity, how did the crank get damaged? Loose pulley nut lead to worn keyway?

 

[Trollhole]

If there is nothing else wrong with the motor take it to a different welder who knows what they are doing and have it welded again.

 

[FJHokie]

Yup, loose nut and wobble lead to damage.

The rest of the engine is perfectly fine; It was rebuilt 40k miles ago by the PO and I put a brand new OEM carb on it last year.

 

[SDFJ60JFK]

Find a good welder they will make it work again. To save yourself some dough take it apart down to the crank snout and replace the crank seal yourself. A good welder will be able to mate the two pieces.


Are you sure that you can repair the nut and do it correctly???


John

 

[torfab]

Budget 10k for a diesel swap, engine, trans, and adapters will run up the bill pretty fast. I would weld it properly if I was cash conscious

 

[Mark W]

You can braze a new key in place, filling the damaged portion of the crank and carefully grind/smooth it down. It can be down without removing the crank from the engine or the engine from thew rig. I have done it a few times.


Mark...

 

[FJHokie]

hmmm.....

I'm thinking of going the cheap route, if Mark W is right, i might be able to re-weld. However I hate spending money on temporary bandages; anyone else tried repairing a crankshaft while still in the engine and rig?

 

[Mark W]

It is not a temporary bandage. I have done this repair on 5 engines. A couple have over 50K on the repair since I did it. Considering how long it has been since I talked to the owners of these particular rigs, they might have twice that.

Do not weld it. Braze it. fill the damaged section of the crank around the original keyway. then use a dremal and small files to remove the excess and smooth it down. When you are done you will have an area where the crank is brass colored instead of silver. other than that it will look and it will perform as original.


Mark...

 

[FL cruiser]

I did the repair to a diesel. If it worked on a diesel, it should hold up very well on a 2F.


I cut an extra keyway cut in the balancer 180 deg from original. I got two pieces of key stock. one 1/4" with a 3/16" step. The other a 3/16" square. I got a dremel tool and cut a 1/4" groove where the original woodruff key was. The 1/4" part of the key will fit in the new crank slot, and the 3/16" step portion will go in the balancers original keyway.
I cut another 3/16" slot in the crank 180 deg away. the square 3/16" key lines up with the new slot in the balancer.

If you take the balancer to a machine shop and ask them to use a broach to press in a new keyway. The process only took them 15 min and only cost $20

Machine shops will have stepped key stock.

 

[mwalls54]

There is always this option and he is close.
https://forum.ih8mud.com/va-dc-md-c...f-block-rebuilt-less-than-1000-miles-ago.html

 

[FJHokie]

Before I do an engine swap I'd like to try to get my crank pulley repaired (brazed and re-key) b/c the engine is in great condition and rebuilt only 40k/5years ago by the PO.

I"m having a hard time finding a Welder/Fabricator/Mechanic that seems knowledgeable and trustworthy in the Northern VA / DC area... any suggestions?

The minute I mention "braze" they all get scared away and they want to rebuild the engine instead.

 

[torfab]

Have you tried to talk to a machinist or fabricator instead? Guys who are good at this stuff are hiding in unlikely places somtimes...

Hope that was helpful 8p|