welded crankshafts

[1929]

I guess its been the norm for many years of welding the old crankshaft to counterbalance the engine, is it overkill to just go and buy a new scat crank instead? Can the welds be trusted in the rebuild? Did anyone ever hear of a problem with the weld?

[hardtimes]

Hey 1929,
You can still buy the last crank that Henry made, in 1932 , for his B engine. That crank is already with integral counterweights from the Ford factory. These cranks are FULL size and available and a commonly called a C crank. I would and have preferred this crank over the scat which has B sized mains, but A size rod journals. I think that unless you are going to run your engine at the salt flats at very high rpms, that Henry's C crank , even drilled correctly for full oil pressure, is as good as WE have it right now. I will add that I have a C drilled crank in my present B short block build, that used to live at Bonneville, until the rear flange was snapped off of the crank. The crank was welded with new flange and I'm pleased to be able to use it again. Those boys that run at the salt use these A/B engines harder than any of us guys will. Hope this helps you out in your thinking. Of course if you are set on A sized rod throws, you can have the full sized B throws cut down..lol

[gwhite]

Originally Posted by hardtimes

Hey 1929,
You can still buy the last crank that Henry made, in 1932 , for his B engine. That crank is already with integral counterweights from the Ford factory. These cranks are FULL size and available and a commonly called a C crank. I would and have preferred this crank over the scat which has B sized mains, but A size rod journals. I think that unless you are going to run your engine at the salt flats at very high rpms, that Henry's C crank , even drilled correctly for full oil pressure, is as good as WE have it right now. I will add that I have a C drilled crank in my present B short block build, that used to live at Bonneville, until the rear flange was snapped off of the crank. The crank was welded with new flange and I'm pleased to be able to use it again. Those boys that run at the salt use these A/B engines harder than any of us guys will. Hope this helps you out in your thinking. Of course if you are set on A sized rod throws, you can have the full sized B throws cut down..lol

SCAT makes a counterbalanced Model A crank with the correct 1.625" main journals; http://www.scatcrankshafts.com/produ...e/crankshafts/

[hardtimes]

You are correct regarding the scat A crank.
1929 did not mention whether he wanted an A or B crank. He wanted counterweights and my mind went right to model B/C cranks with integral counterweights, because that's what I use. I figured that maybe 1929 did not know of this counterweighted crank. That said, if you want a scat to install in a B block, then I stand on what I wrote regarding that crank having B size mains and A size rod throws.

[BRENT in 10-uh-C]

Originally Posted by gwhite

SCAT makes a counterbalanced Model A crank with the correct 1.625" main journals; http://www.scatcrankshafts.com/produ...e/crankshafts/

Originally Posted by hardtimes

You are correct regarding the scat A crank.
1929 did not mention whether he wanted an A or B crank. He wanted counterweights and my mind went right to model B/C cranks with integral counterweights, because that's what I use. I figured that maybe 1929 did not know of this counterweighted crank. That said, if you want a scat to install in a B block, then I stand on what I wrote regarding that crank having B size mains and A size rod throws.

You both likely already know this but it might be worth saying for those who don't, ....SCAT will machine a crankshaft to whatever specs you choose to order. The additional cost(s) are only proportional to the additional time it takes to make the changes.

[BRENT in 10-uh-C]

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Originally Posted by 1929

I guess its been the norm for many years of welding the old crankshaft to counterbalance the engine, is it overkill to just go and buy a new scat crank instead? Can the welds be trusted in the rebuild? Did anyone ever hear of a problem with the weld?

Whew... Lots of questions. Yes, there have been failures with welded cranks. Know the reputation of the one installing the weights. Dan Price makes sweat-on weights that are similar to the BB crank. The issue I see with those modifications is finding a crank that is not already been machined too far undersized where the effort in counter weighting is short lived. Is it overkill to move ahead with purchasing the SCAT crank? IMHO the answer is "No". The SCAT crankshaft is a very nice piece, and while it is not for everyone, the mass weight and modern technology really make a nice unit. I would have this chat with your (experienced) engine rebuilder to get his opinion too.

[Pete]

Originally Posted by 1929

I guess its been the norm for many years of welding the old crankshaft to counterbalance the engine, is it overkill to just go and buy a new scat crank instead? Can the welds be trusted in the rebuild? Did anyone ever hear of a problem with the weld?

1- Overkill, probably for a street engine.
2- The welds can be trusted if done by a qualified welder.
(Sometimes hard to find)
3- Yes.

Besides the counterweight welding, it is quite common to weld up the bearing journals and grind back to standard both with stock stroke and longer stroke for racing.

[Kohnke Rebabbitting]

Dan Price counter weights are NOT Swaged on, they are shrunk on, big difference.

[BRENT in 10-uh-C]

Originally Posted by Kohnke Rebabbitting

Dan Price counter weights are NOT Swaged on, they are shrunk on, big difference.

Yes, you are correct. I should have used the word Sweat instead. I will change that typo.

[1929]

So could the opinions be that maybe iam better off getting a new crank to be on the safer side? I do know it will cost another $1000 on a rebuild, and why not cause Iam sure this rebuild will outlast me.

[hardtimes]

Originally Posted by 1929

So could the opinions be that maybe iam better off getting a new crank to be on the safer side? I do know it will cost another $1000 on a rebuild, and why not cause Iam sure this rebuild will outlast me.

Hey 1929,
Yup, why not...it is your money, eh !
I'd appreciate knowing just where you get the 'new crank' for $1000, though ?
Last new scat that I saw ready to be installed from the bench , had a price tag of rounded up....$1600. That did not take into account fitment and/or bearings.

BTW..it is interesting news that scat will cut a crank to whatever specs needed. I'm thinking immediately of Tods 5 main block !
Just what information , other than rod/main size , will be needed ? Maybe five main journals, six crankshaft flange holes , two locating pins , all for B size block ?? Hardened surface, drilled..anything else Never ordered one.

[1929]

Originally Posted by hardtimes

Hey 1929,
Yup, why not...it is your money, eh !
I'd appreciate knowing just where you get the 'new crank' for $1000, though ?
Last new scat that I saw ready to be installed from the bench , had a price tag of rounded up....$1600. That did not take into account fitment and/or bearings.

BTW..it is interesting news that scat will cut a crank to whatever specs needed. I'm thinking immediately of Tods 5 main block !
Just what information , other than rod/main size , will be needed ? Maybe five main journals, six crankshaft flange holes , two locating pins , all for B size block ?? Hardened surface, drilled..anything else Never ordered one.

What I ment was $1000 for the crank if you take away the $500 for the labor on the old crank, instead of spending $500, spend another $1000 for a new one that's about $1500

[just plain bill]

Joe Gemsa was quoted as saying that he would get 3 hard races with a C crank and up to 10 races with a B with welded on weights. My source for this comment was lost when friend passed and little booklets disappeared.