question about welding crank

[Six_Silver]

I was told by a Chevy friend that if you have a crank that has been cut, that you can have it welded back to std/std. He also told me that the crank then becomes stronger. I can have this done for $65.

Any advice on this situation? Does this process not apply to the turbo crank because of the rolled fillets or for any other reason?

 

[sixgun86gn]

I would not use the welded crank in a performance situation.I do however have a non turbo crank in my motor and it is fine.I see no problem with a .010/.010 NA crank because the rolled fillet thing really has no proof behind it.If you want to go cheap do it that way rather than welding the crank.Heat does funny things to metal.Otherwise buy another turbo crank if you don't feel comfortable with anything else.NA crank is $100 at the local rebuilders ready to drop in,a turbo crank is around $300 and needs machine work usually at that price.

 

[Six_Silver]

He is a very very knowledgable engine builder and was positive it would strengthen the crank as it has in other applications he has used.

I guess I can use my other std/std crank and have it cut .010/.010 to use instead.

Any one else?

 

[Nick Micale]

Originally posted by sixgun86gn
....................I do however have a non turbo crank in my motor and it is fine.I see no problem with a .010/.010 NA crank because the rolled fillet thing really has no proof behind it.............................../B]

You mean Buick could have used a 120 HP non-turbo crank in the turbo motors and saved all that extra $$$?

 

[bruce]

Originally posted by Six_Silver
I was told by a Chevy friend that if you have a crank that has been cut, that you can have it welded back to std/std. He also told me that the crank then becomes stronger. I can have this done for $65.
Any advice on this situation? Does this process not apply to the turbo crank because of the rolled fillets or for any other reason?

Crank welding is an art form.
It's all about the guy doing the work.
65 sounds awful cheap. And there are several ways of doing it, arc, vs Plasma. And as I recall it generally took hard chroming or nitriding afterwards to generate a really good crank. But, what limited association I had with welded cranks was for the old AA/FC cars, along time ago.
HTH

If you go this route, be sure to keep us posted on whatcha find.

 

[turbo buicks]

Originally posted by Nick Micale
You mean Buick could have used a 120 HP non-turbo crank in the turbo motors and saved all that extra $$$?

maybe so. what if they thought it gave it better strength but it turns out it doesnt. people also used to think the world was flat. i believe a buddy of mine's been running a non-turbo crank for some time now, no probs. (redregalT)

 

[Ormand]

Rolled Fillet

"You mean Buick could have used a 120 HP non-turbo crank in the turbo motors and saved all that extra $$$?"

They could have saved some money in initial cost, but spent big time on warranty. The rolled fillet has been PROVED to work, it increases the fatigue life of the crank by a substantial amount. GM and others have tested their parts for thousands of hours. Anybody who thinks the fillets don't work probably still believes that the world is flat... The rolled fillet is pure science/engineering, it is not some magic art, with no theory to explain it. Fatigue cracks will initiate only at a surface under tension, and the rolling process leaves a residual compressive stress, such that cracks will not initiate at the fillet area.

 

[turbo buicks]

Re: Rolled Fillet

Originally posted by Ormand
"You mean Buick could have used a 120 HP non-turbo crank in the turbo motors and saved all that extra $$$?"

They could have saved some money in initial cost, but spent big time on warranty. The rolled fillet has been PROVED to work, it increases the fatigue life of the crank by a substantial amount. GM and others have tested their parts for thousands of hours. Anybody who thinks the fillets don't work probably still believes that the world is flat... The rolled fillet is pure science/engineering, it is not some magic art, with no theory to explain it. Fatigue cracks will initiate only at a surface under tension, and the rolling process leaves a residual compressive stress, such that cracks will not initiate at the fillet area.

well ya if ya wanna get technical about it. haha

 

[sixgun86gn]

Science is based on THEORY.I will prove you wrong by running in the 10s on mine.11.69 in a full weight GN takes a good bit of power and that is only until I get some bigger injectors.I would say that is enough proof that the average turbo buick (11.xxs to stock) can use a NA crank without fear.Lets see who all has used a NA crank and ask them what they run.I know for a fact there are others faster than I am.

 

[Six_Silver]

FWIW,

This will not be a mid-11 second application. Mid 10's is more realistic.

 

[sixgun86gn]

Same with mine.I just need more pump and injector.Right now the car cuts out at the top end.I will say this though,on a chassis dyno my car put out over 400 hp and 470 torque on 16# of boost and 93 octane.I think the crank I have is plenty stout.If you want to go mid 10s,by all means buy a turbo crank or try your welding thing.I was just stating my opinion that a standard crank is just as strong and $300 to $350 for a stock crank is ridiculous just for some rolled fillets that are usually almost gone after grinding.I by no means want some one to short their combo,I was just saying I have done ok with a NA crank so far.I have seen plenty of stock SBC cranks handle 600hp and they don't have rolled fillets,same with ford motors.I WILL run deep in the 10s on this crank,just watch me.If it lets go,so be it I'll be the first to admit I was wrong.If it hangs on for a while I will be the first to say "I told you so" to all the guys wanting ridiculous prices for cranks.They want you to beleive you have to have it so you buy a turbo crank from them.

 

[Six_Silver]

Back to the original question....


Does anyone know if welding the stock (rolled fillet turbo) crank will be weakened?

Any machinists out there?

Thanks

 

[sixgun86gn]

My original turbo crank was badly gouged and I asked a machinist about it and he said it would weaken it.That is the reason for my original post and that is how I got the crank I have.I am sure there are plenty of machinists on this site that can help you.All I know is what I was told when I rebuilt my motor.Sorry about the other posts,I am no expert by far.....no dummy either.I would like to know for sure myself if this is a good method,sure could save me some $$$.Good luck.

 

[The Radius Kid]

Originally posted by Six_Silver
Back to the original question....


Does anyone know if welding the stock (rolled fillet turbo) crank will be weakened?

Any machinists out there?

Thanks

Yup,don't do it.I'd rather use an N/A crank than a welded T/R crank.

 

[Nick Micale]

Originally posted by Six_Silver
I was told by a Chevy friend that if you have a crank that has been cut, that you can have it welded back to std/std. He also told me that the crank then becomes stronger. I can have this done for $65. .......Any advice on this situation? ......

Here are a couple comments relative to your crank. Our local crank shop would charge about $200+ to have any welding done and do the other items required - turn/finish to correct finish dimensions, straighten as welding will deform it, polish journals and mag for proper weld and any other cracks.

Since we mainly do performance builds, we never go this route.
We also never use a non-turbo crank in a performance application as a couple have been destroyed, even one that was purchased new, as the owner thought it was correct.

As far as it being stronger, I will let someone more expert than me address that comment?

 

[c&cgn]

Originally posted by sixgun86gn
Same with mine.I just need more pump and injector.Right now the car cuts out at the top end.I will say this though,on a chassis dyno my car put out over 400 hp and 470 torque on 16# of boost and 93 octane.I think the crank I have is plenty stout.If you want to go mid 10s,by all means buy a turbo crank or try your welding thing.I was just stating my opinion that a standard crank is just as strong and $300 to $350 for a stock crank is ridiculous just for some rolled fillets that are usually almost gone after grinding.I by no means want some one to short their combo,I was just saying I have done ok with a NA crank so far.I have seen plenty of stock SBC cranks handle 600hp and they don't have rolled fillets,same with ford motors.I WILL run deep in the 10s on this crank,just watch me.If it lets go,so be it I'll be the first to admit I was wrong.If it hangs on for a while I will be the first to say "I told you so" to all the guys wanting ridiculous prices for cranks.They want you to beleive you have to have it so you buy a turbo crank from them.

With all the money you have to put into a car to run 10's, you're worried about $300 on the crank? Why not use and 84/85 block while you're at it? You might be able to save another $200

No such thing as a "budget" 10-second car. At least, not a consistent one.

 

[tminer]

Originally posted by sixgun86gn
Science is based on THEORY.I will prove you wrong by running in the 10s on mine.11.69 in a full weight GN takes a good bit of power and that is only until I get some bigger injectors.I would say that is enough proof that the average turbo buick (11.xxs to stock) can use a NA crank without fear.Lets see who all has used a NA crank and ask them what they run.I know for a fact there are others faster than I am.

There is a big difference between saying that a N/A crank can work OK vs rolled fillets do nothing to strengthen a crank.

And science is not based on theory. There is theoretical science, but that is a differ animal. Science takes a theory and proves it. Observation of real world performance is closer to theoretical science than hard science since it only tends to support a theory, not actually prove it.

Fact is that one will never know the true strength or durability of any given crank untill it has failed. Rolling the fillets just increases the odds. I am sure that there are n/a cranks that are stronger than some turbo cranks. But take that same n/a crank and roll the fillets and it will be even stronger.

Any crank is living on borrowed time in a performance application. Rolling the fillets will extend one's credit. The Buick Power Source manual says to replace even a turbo crank after 12 hours of competion use even if it mags OK. Cheap insurance even though it is a good piece and failures are quite rare!

Tom

 

[Mease Performance]

Re: Re: question about welding crank

Originally posted by Nick Micale
Here are a couple comments relative to your crank. Our local crank shop would charge about $200+ to have any welding done and do the other items required - turn/finish to correct finish dimensions, straighten as welding will deform it, polish journals and mag for proper weld and any other cracks.

Since we mainly do performance builds, we never go this route.
We also never use a non-turbo crank in a performance application as a couple have been destroyed, even one that was purchased new, as the owner thought it was correct.

As far as it being stronger, I will let someone more expert than me address that comment?

Whys everyone gotta pick on someone on this board LOL NICK you started it!!!!

We would NOT reccomend welding a RF turbo crank, when the process is done it WILL take strength away from the crank

Who said rolled fillets dont help?

NO FREE DOWNPIPE FOR YOU!!!!! J/K

in all seriousness, do you actually believe GM would do SOMETHING that cost them MORE in the long run?????

thats what I thought

Keep the turbo crank in the motor, YES an NA crank will work, and have seen many run them without problems, but in the same ":sense" they werent pressing 28psi and going 11.0

 

[sixgun86gn]

Originally posted by c&cgn
With all the money you have to put into a car to run 10's, you're worried about $300 on the crank? Why not use and 84/85 block while you're at it? You might be able to save another $200

No such thing as a "budget" 10-second car. At least, not a consistent one.

HAHAHAHA...this will really get you.I built that shortblock at a time when I really had no money to do it all the way.I was just stating that I have done OK with a NA crank and now would not buy a turbo crank for $300+ after seeing what mine has been through.To run in TSM a turbo crank is definitely required at the least at those power levels,but I don't want to race TSM just hit the 10s a time or 2 if I can.Oh BTW I have a TA block in the works,its getting a billet crank and all the good stuff.Times are good for me now and I am taking advantage of it.I really want to see what mine will take and I don't care if it spits out the bottom,if it doesnt oh well I tried.Hey,Nick are you done fabbing the poly motor mounts? I may be starting on that shortblock sooner than expected .
Patrick

 

[sixgun86gn]

Keith,I don't feel I am being picked on.I feel that I am being educated by those more knowledgable than me.I followed the advice of someone I respect and I now see that he didn't understand the science behind the crank difference.I am still new to the Buick world with only 3 years at most ownership.Thanks guys for making more sense of the subject for me.I did not mean to start an argument and hijack this thread though.Silver-six I am deeply sorry this happened on account of my statements.