What am i doing wrong, broken 2 crankshafts??

[johni]

Hi i have broken 2 crankshafts, is there a problem whit VMAX crankshafts, the first one was 1300 bigbore whit flatslide carbs, and the secont one was whit only flatslide carbs,
Is there made an extra strong crank for the VMAX?

 

[4gasem]

I believe there's an issue with them. Are you turning them down to clean them up during rebuild? Sean Morley know a HELL of a lot more.

Let's wait for him.

Chris

 

[one2dmax]

Describe Broken? Are you literally breaking them in two? We've only broken one ever and that was a repaired crank and it broke the end off where the flywheel hooks onto. Or by breaking are you spinning the bearings? If you are spinning bearings are you using the same block?

Sean

 

[johni]

They are both broken in two pieses, the first in the mittle, and the secont between rod and the sproket to the clutch:ummm:

 

[johni]

It was two bloks nr1 was a 1992 bigbore , and nr2 is a 1986 stock

 

[one2dmax]

Not sure what you are doing. I've beat the crap out of these things and not broken a crank (other then the noted end breaking off).

Sean

 

[johni]

when i am rebuilding the engine whit a new crank is there anything i can do too prewent it blowing up again ?
can the crank be made stronger ?

 

[4gasem]

Anyone try cryogenic treating?

 

[KJShover]

Anyone try cryogenic treating?

Every engine I've ever done, I've had the pistons,crank, and rods done.

I've even had a couple of the barrels on my rifles done.

http://www.300below.com/

 

[KJShover]

when i am rebuilding the engine whit a new crank is there anything i can do too prewent it blowing up again ?
can the crank be made stronger ?

You can spend a few thousand $ and send it to falicon. Are you using the same engine cases? or are you replacing them as well.

busting cranks isn't exactly the easiest thing to do, normally other parts will give first.

 

[johni]

The first time the hole engine blow up, the cases, crank,rods,pistons and both heads where blown to pieses, ( it happend whit 9500rpm ).:bang head:

 

[4gasem]

Every engine I've ever done, I've had the pistons,crank, and rods done.

I've even had a couple of the barrels on my rifles done.

http://www.300below.com/

LOL That's OUR customer in Decatur... We have a store there. Believe it or not they buy A LOT of liquid nitrogen from us...

 

[one2dmax]

Sounds like too many times over-revving and using stock rods. Stock Rods do not like much over 9K-9500K rpm even on thier best days. They will hold up to even 1500 power if rpm's not would out too much.

.0015-.0018 bearing clearance. Make sure there is some side to side clearance. Probably have thrust surface damage which is not a normally repairable thing. Get an overdrive oiling system like what we sell. Maybe some aftermarket rods (we sell Carrillo's).

Sean

 

[KJShover]

LOL That's OUR customer in Decatur... We have a store there. Believe it or not they buy A LOT of liquid nitrogen from us...

I didn't know you guys were into that. For some reason I was thinking you did something else. The next time I need some cryo work done, I'll send it your way. or are you just on the supply side of things?

 

[rhoke]

Ya i just believe he is in the supply, pretty sure. if not he will correct me. Roy

 

[4gasem]

We supply! We send them the liquid and they do the work. I know they've treated some of our concrete bits that our cryo techs use and they said they lasted a lot longer.

Chris