Merc 4" Crank Damage

Looking at picking up a few 8BA's from a fellow HAMBER. Also a 4" MERC Crank with a little damage. Please see the pics below, not a deal breaker if it can't be repaired but we are both curious.

Fixable? or Yard art?

Thanks in advance.

 

hard to see , is that a crack in the first picture?

 

Was probably that way from the factory. Only one way to know for sure, have it balanced.

 

looks like a crack to me

 

I am guessing a crack = yard art.

 

This is standard I think it is where the sprue was attached. I have several just like this.
Freddy

 

I think that is simply where casting sprue was broken away...this was a delicate operation done by an experience machinist with a sledge hammer.
If worried, take that area down to shiny with a body grinder and examine surface, if real worried have it fluxed.

 

It's the way there made if I was better at this puter thing I'd post some pic's.

 

To translate...that is the bottom of the hole where melted Model T's and surplus Sherman tanks were poured into the hole. When the crank was pulled out, that site was a pillar of iron made so it was narrowest at that level and would so break right there. Someone then smacked the pillar with a hammer and sent it back to the foundry to be re-melted, and the carnk went off to be machined.

 

Well put, Bruce.

 

It looks like a parting plane in the casting. As long as it doesn't look it was caused by something broken internally (hammered to ****..), you should be okay.

Bob

 

Have it checked by a very qualified engine machinist.

A. Magnafluz inspection for cracks.
B. Check for straightness.
C. Inspect and mic all journals.

I have all the specs if you need them.

I agree with the sprue theory.

 

I have half a dozen Merc cranks and they all look like that. No worrys!

 

I'll be damned! I'm the current owner of the aforementioned crank (although rgrhoward and I have a deal in the works). The crank was sold to me as NOS, I didn't look it over real well, got it home, saw that, and relegated it to the 'deal with later' pile. Very interesting. Oh well, buy high, sell low I always say.

 

Yup, as stated, they all look that way.

 

Thanks for all the info guys. Learn something new everyday.

Only hope i can p*** on this knowledge someday.

 

Looks fine to me unless there is a crack in there that didnt com through in the pics. Run it!

 

If you're going to have it 'checked' or machined, have them shot peen it first. (then magna flux)

I've always shot-peened 4" cranks. Ak Millar and Ray Brock were staunch advocates...
I apprenticed in a Ford/Mercury shop.
(never seen excessive breakage in flathead cranks, but there were lots of 'Y' blocks that broke 'em...239, 272, 292, 312...)

 

Easiest thing is take it to your local reliable machine, or balancing shop. They'll give you the straight poop.

4TTRUK