"Blown" Ford 351

That crank is dead bro, The snout likely didnt break the crank likely broke a bit back and what you see is the runout at the snout.... even if the snout is the only thing broken it is part of the crank so the crank is broke. You would not want to spend any money fixing that crank. Perhaps the block as well... but no good either way.

If the block is cracked as well, then I'm gonna be really sad. Then I'll do the next thing.

Keno posted a picture on June 28th showing the rear main seal on the crankshaft.
The wick lines or Helix are shown on the crankshaft.
If your new crankshaft does not have a helix it can turn in either direction.
I bet a replacement Scat or Eagle crankshaft would not have a Helix on the seal surface and those are usually available for less than $250.
You can also have a std rotation crankshaft polished to take off the helix as long as they don't take too much off you should be good. Wish you kept the old crank that came with your block.

William, you have a Private Message...

A straight crank will spin straight even without the #5 bearing in the engine.
What made your crankshaft wobble or was it just a loose harmonic balancer?

A bad crankshaft bearing journal can be welded up and ground smooth again.
Welding and grinding would add an extra $150 to the crank repair, Estimate but cranks are out there and availabe so replacement is probably the best option.

The Tangs are only on the bearing for install proper location. They do not hold the bearings in place. Proper crush of the bearing holds it in place.
Crush is the amount of clamping force on the bearing when your properly torque the bearing cap in place. Some new engines do not use tangs on the bearings any longer.
The stock engine is approximately 3.5" stroke on the 351W. I would have to look it up to see if it is actually 3.485 or 3.510 does not matter, 3.5 is what you want for a stock replacement.
The 3.75 and longer strokes are all for upgraded engines with more cubic inches created by the longer stroke.
These are options you can choose but to go that route with alonger stroke you will need to add a lot of money. New Pistons, Maybe Connecting Rods, Balancing and maybe clearance work inside your block so this long stroke could work.

mine measure 2.4 without the bearing. inside diameter of the rod end.

You might do some reading and see if you assembled the bearing caps correctly. They have one correct way but can bolt on wrong if you do not know the orientation for each cap.
Same for the rods, they usually have one side that faces the other rod and one side that faces the crank throw. Something is wrong.
Do you have a picture of your crankshaft snout?

That crank is a nearly 3' long piece of machined cast steel. It will not twirl ever. It will rotate straight unless it is broken. It can't bend without breaking. You mentioned it rings like a bell so the part you are working with is not cracked.
That is why I asked for a picture. I am thinking you have an inch or 2 missing off the end of the crank now. I could be wrong. It may be inside your harmonic balancer at this point.

I'm telling you it was twirling. I could be losing my mind, but it was twirling.

Duane, no offense taken. I agree. Just put the crank back on the bearings which are in the engine as it sits upside down outside. Spun it and it wobbles a bit. Like it's bent. There is a ton of clearance at the front bearing prolly because the crank is worn down so much. Also the #5 bearings appear to have shrunk. They don't fit the block anymore. Not just worn down but overall smaller. I'm done for now. Found a short block at 1200 bucks delivered. That would be the best next step prolly. I'm beat.

The missing material in the damaged bearing has now gone through the entire engine and may have damaged other engine bearings or your piston rings depending on how long you ran it after the failure.
At this point your thoughts for a new short block may be exactly the easy way to enjoy this boat again.
Without going back and reading each post I don't remember are your heads in good shape? No reason to put old heads on a nice new short block.

Mourning Wood made a very gracious offer to drive here to my house and help with the engine. Then I tore it down and found all the damage. I declined his offer in order not to waste his time. I'm light years away from a step by step rebuild at this point. In fact a rebuild is not being considered at this point. I'm thinking new engine if I want this boat. I'm grateful to Mourning Wood.

After completely giving up last year on the boat I just wrapped the good bits up and stuck them under my house. Offered the boat for free to everyone I know so I could use the space in the driveway for my car, No one bit, Sunday I walked down to the ramps at the lake and saw everybody putting their boats in and that did it. I'm back in the game. Going to buy a short block and dig in AGAIN.

63 Skier wrote: You really need to, once you sort through the problem, start the boat on the trailer for these test runs.  If it was on the trailer and you didn't have cooling water coming out the pipes you'd know to shut down immediately and figure it out.  $20 in parts at the hardware store and you've got a safe way to feed it water on the trailer.