Balancer fit

what would cause a balancer to weld itself onto the crank ??? fit was .0005" press. used never-sieze, and installed with a tool.
on a previous build, the balancer welded itself onto the crank, that fit was .001 press. actually hadda cut that one off.
the engine is a 4-1/2" stroke, is there too much goin on here ?

Vibration / harmonics

Balance wasn't right ! Been there done that ! overbalance to 52% now
Frank

other thing I thot about is the keyway dimension vs key. maybe it's too big and letting things rattle around ... i'll have the shop recheck the balance.
thankx, eh.

Had the same problem! Frank can you elaborate?

damper would weld on the the converter snout would weld in the back of the crank ! 52% over balance fixed it
Frank

Micro welding because of vibration

JACKAZZFLATZ wrote:what would cause a balancer to weld itself onto the crank ??? fit was .0005" press. used never-sieze, and installed with a tool.
on a previous build, the balancer welded itself onto the crank, that fit was .001 press. actually hadda cut that one off.
the engine is a 4-1/2" stroke, is there too much goin on here ?

detonation, just by chance was the dampener bolt kinda loose instead of tq'ed ?

dampner bolt was torqued to 115 #ft. BakerEng will overbalance @ 52%. thankx for the help youse guys.

we spin our 600 inch to 9300 and the 712 gets shifted at 88-9000
Frank

well, the 52% didn't work. found out this afternoon. welded again. good thing I have a puller from hell, needed it.

Usually it is because the damper is not tuned correctly to diminish the frequencies involved.

Changing the balance factor can change those frequencies ... or to light of a 3rd from the front counter weight; (shows up as upper bearing stress on 2nd & 4th main bearings; center counterweights usually cure that kind of problem), or the rubber durometer or whatever damping factor within the damper is not correct or the weight of the outer ring is not heavy enough or some of all of the above.

Sorry in advance if I missed it somewhere but what brand of balancer?

My balancer (FMS) was also super tight on my 4.5 stroke Scat crank. And I literally can’t get the crank sprocket off. Motor only had 1000 miles and 20 passes

My cloyes crank gear was super tight on my Lunati 4.5” crank, just get out the propane torch and heat it up a little bit. With some heat mine slid off very easily.

damper is from Innovators West. Short crank nose.

Have you called Chris?

no, I haven't. i'll put that on the reassembly list, thankx, eh.

I was reading this thread the other day and thinking about this problem. I wonder if it might be metallurgical in some cases?

I just finished up a freshening on an engine for my monster truck customer. That engine has a Sonny Bryant 4.500 stroke forged crank with a "boss" snout and a double keyway setup. I used a neutral balanced small block Ford crank hub and I fitted it with .0005 interference. I always install it using some anti seize compound and then torque the ARP crank bolt tight using an impact wrench. This particular engine has been used for more than 15 years and it has seen TONS of run time. The crank snout always looks great there are a few very minor discolored areas on the snout itself but I've never seen any galling what so ever. These cranks are nitrided are far as I know but I don't think that the hub is anything special and the surface is honed inside from when I fitted it originally. Wouldn't you think that the tortional vibration would be pretty high on even a mild blown alcohol engine like this one? It gets turned to about 7200-7500rpm max most of the time.

At the shop I have a big Chevy engine that was also built about 15 years ago for a mud racer and had never been apart. No where near the run time or power output as the monster truck but that balancer was very difficult to remove when I tore down the engine. It had places where it had welded itself to the crank snout. That engine has a 4.250 stroke Eagle forged crank with center counter weights and the balancer was a Powerbond SFI piece. I know it was also fitted with .0005 interference when I originally assembled the engine. Fortunately the crank snout was easy to polish and it will work again.

DaveMcLain wrote:I was reading this thread the other day and thinking about this problem.  I wonder if it might be metallurgical in some cases?  

I just finished up a freshening on an engine for my monster truck customer.  That engine has a Sonny Bryant 4.500 stroke forged crank with a "boss" snout and a double keyway setup.  I used a neutral balanced small block Ford crank hub and I fitted it with .0005 interference.  I always install it using some anti seize compound and then torque the ARP crank bolt tight using an impact wrench.  This particular engine has been used for more than 15 years and it has seen TONS of run time.  The crank snout always looks great there are a few very minor discolored areas on the snout itself but I've never seen any galling what so ever.   These cranks are nitrided are far as I know but I don't think that the hub is anything special and the surface is honed inside from when I fitted it originally.  Wouldn't you think that the tortional vibration would be pretty high on even a mild blown alcohol engine like this one?  It gets turned to about 7200-7500rpm max most of the time.

At the shop I have a big Chevy engine that was also built about 15 years ago for a mud racer and had never been apart.  No where near the run time or power output as the monster truck but that balancer was very difficult to remove when I tore down the engine.  It had places where it had welded itself to the crank snout.  That engine has a 4.250 stroke Eagle forged crank with center counter weights and the balancer was a Powerbond SFI piece.  I know it was also fitted with .0005 interference when I originally assembled the engine.   Fortunately the crank snout was easy to polish and it will work again.  

Perhaps the Eagle crank does not have the same quality heat treatment as the Bryant crank??
I know that when Eagle products first started coming to market in the early 90's....a very lot of it was absolute crap!! Cranks that were out of round on the journals, and sometimes one main journal would a little too big, and the next one would be small.
I worked in a well known race engine shop here in So. Cal back then, and we were rejecting a lot of that early Eagle stuff.
I know the quality has improved over the years, but it is possible that a few parts and pieces still get out the door that is not of high of a standard than the rest.

BBFTorino wrote:

DaveMcLain wrote:I was reading this thread the other day and thinking about this problem.  I wonder if it might be metallurgical in some cases?  

I just finished up a freshening on an engine for my monster truck customer.  That engine has a Sonny Bryant 4.500 stroke forged crank with a "boss" snout and a double keyway setup.  I used a neutral balanced small block Ford crank hub and I fitted it with .0005 interference.  I always install it using some anti seize compound and then torque the ARP crank bolt tight using an impact wrench.  This particular engine has been used for more than 15 years and it has seen TONS of run time.  The crank snout always looks great there are a few very minor discolored areas on the snout itself but I've never seen any galling what so ever.   These cranks are nitrided are far as I know but I don't think that the hub is anything special and the surface is honed inside from when I fitted it originally.  Wouldn't you think that the tortional vibration would be pretty high on even a mild blown alcohol engine like this one?  It gets turned to about 7200-7500rpm max most of the time.

At the shop I have a big Chevy engine that was also built about 15 years ago for a mud racer and had never been apart.  No where near the run time or power output as the monster truck but that balancer was very difficult to remove when I tore down the engine.  It had places where it had welded itself to the crank snout.  That engine has a 4.250 stroke Eagle forged crank with center counter weights and the balancer was a Powerbond SFI piece.  I know it was also fitted with .0005 interference when I originally assembled the engine.   Fortunately the crank snout was easy to polish and it will work again.  

Perhaps the Eagle crank does not have the same quality heat treatment as the Bryant crank??
I know that when Eagle products first started coming to market in the early 90's....a very lot of it was absolute crap!! Cranks that were out of round on the journals, and sometimes one main journal would a little too big, and the next one would be small.
I worked in a well known race engine shop here in So. Cal back then, and we were rejecting a lot of that early Eagle stuff.
I know the quality has improved over the years, but it is possible that a few parts and pieces still get out the door that is not of high of a standard than the rest.

This Eagle crank was really nice size wise and the bearings all look absolutely great but I do wonder about the heat treating/surface hardness on the snout itself.  I think that Eagle cranks are induction hardened on the journals and not nitrided but I'm not sure.  Nothing in the engine shows any signs of distress from torsional vibration.  The timing set looks like it hasn't even been run.  I wonder if the original poster has a crank that's similar in his big Ford?

I have a circle track customer's engine that's coming in for freshening and it also has an Eagle forged crank with an ATI damper. It is a 500 horsepower application with a crank that has the counter weights cut way down with a light bob weight. That crank has about six seasons of racing on it and it's been two years since I've had it apart. I'll see what it looks like. That crank was fine on the sizes of the journals but the snout was undersized. I had to get an under sized hub and hone it to fit.