Welding a crank..

[Steve V]

I have a nice std/std crank that has the thrust surface ate up. Can it be welded and then machined back down?

This was one of my experiments and lets say it didn't go too well. Lost #2,#3 main and cam bearings,killed the thrust. I oversized some bearing holes,reclocked some cam bearings with smaller holes. This was a daily driver till about 9 mons ago then it got maybe 500 miles put on it till now. Pulled the pan chasing an oil leak and I opened a can of worms.

Motor is gonna be a stockish build with 6157,ptc 2800,60's,slic...nothing crazy.

 

[Kip]

Simple answer yes.

Hope that helps,Kip

 

[BobbyBuick]

You can buy oversized thrust surface bearings and turn the thrust surface .040 max .you can also spray weld it but dont know how well that would hold under severe duty conditions .it would probably hold up in a street driven car

 

[750H.P.V6]

Simple answer yes.

Hope that helps,Kip

Kip,

Doing a weld repair on a cast crank is usually a bad idea. Personally I won't run a weld repaired forged crank either. Stock cranks aren't of great enough value to mess with it. Just get another one.

Neal

 

[charlief1]

Kip,

Doing a weld repair on a cast crank is usually a bad idea. Personally I won't run a weld repaired forged crank either. Stock cranks aren't of great enough value to mess with it. Just get another one.

Neal

I gotta agree with you. If it was a forged crank then sub-arc welding can repair it but you'll loose some strength. Not much but a little. Since the stock crank is cast you will weaken the crank and it could be used for an NA app but I wouldn't turn it that hard.

 

[Squid4life]

This is kinda apples to oranges, but before my current profession I worked at a machine shop that built a lot of SBC/SBF roundy round engines. They would have a crank welded every once in a while, but a reputable repair place that also repaired heads. You could see the blueing from the heat of the weld, and it usually didn't last too long afterwards. Like I said, apples to oranges as they run 12.5:1+ compression and lots of rpm, but, the general idea is the same for me. I am with Neal and Charlie. I would feel safer with an NA crank than a welded one, but that is just me. I would find another crank.

 

[Steve V]

Thanks for everyones input.

 

[Kip]

Kip,

Doing a weld repair on a cast crank is usually a bad idea. Personally I won't run a weld repaired forged crank either. Stock cranks aren't of great enough value to mess with it. Just get another one.

Neal

Neal, I never saw where it was stated it was a cast crank. Answering the question it still can be done.

Take care, Kip

 

[Chuck Leeper]

welded/forged cranks not holding up??????????????

Hmnn.. I wonder how strokers were made, B4 the advent of forged strokers.

 

[Steve V]

Neal, I never saw where it was stated it was a cast crank. Answering the question it still can be done.

Take care, Kip

It is a stock cast crank. std/std

 

[750H.P.V6]

welded/forged cranks not holding up??????????????

Hmnn.. I wonder how strokers were made, B4 the advent of forged strokers.

You just had to stir the pot huh Chuck? Actually you're right. I came from a VW background decades ago where welding / offset grinding to increase the stroke length was done on a regular basis.

Weld repairs on damaged cranks don't seem to fair as well. I've seen more than one weld repaired BMS crank break. I don't like to invite disaster (it seems to show up on its own) so I won't risk it.

Neal