Mallory Metal flying out of crankshaft
Just wondering if anyone else has had an externally balanced 4340 crank balanced to internal specs and have the heavy metal fly out of the crank on the 11th pass. The machinist, if you want to call him that welded the piece into one of the normal balance drill holes not sideways on the counterweight like I have seen. Anyway the piece (1.5" long by 1.0" dia.) came flying out at 6,500 RPM through the pan, the diaper caught it but all 8 quarts of oil also exited and the motor seized, and is a total loss (BBC 496). The hole in the pan is almost 2.5". The machinist told me he had done many of those, and said we must have done something wrong. I wonder what we did wrong except for going to this lying, cheating machinist who took about 7 months to bore and balance our motor to start with. Any opinions?
Rick |
Re: Mallory Metal flying out of crankshaft
Originally Posted by TRChassis
Just wondering if anyone else has had an externally balanced 4340 crank balanced to internal specs and have the heavy metal fly out of the crank on the 11th pass. The machinist, if you want to call him that welded the piece into one of the normal balance drill holes not sideways on the counterweight like I have seen. Anyway the piece (1.5" long by 1.0" dia.) came flying out at 6,500 RPM through the pan, the diaper caught it but all 8 quarts of oil also exited and the motor seized, and is a total loss (BBC 496). The hole in the pan is almost 2.5". The machinist told me he had done many of those, and said we must have done something wrong. I wonder what we did wrong except for going to this lying, cheating machinist who took about 7 months to bore and balance our motor to start with. Any opinions?
Rick Costs money to go to school !!!!! Here is the way we install mallory http://i7.photobucket.com/albums/y27...S/MikeM003.jpg |
Re: Mallory Metal flying out of crankshaft
Originally Posted by hink
Originally Posted by TRChassis
Just wondering if anyone else has had an externally balanced 4340 crank balanced to internal specs and have the heavy metal fly out of the crank on the 11th pass. The machinist, if you want to call him that welded the piece into one of the normal balance drill holes not sideways on the counterweight like I have seen. Anyway the piece (1.5" long by 1.0" dia.) came flying out at 6,500 RPM through the pan, the diaper caught it but all 8 quarts of oil also exited and the motor seized, and is a total loss (BBC 496). The hole in the pan is almost 2.5". The machinist told me he had done many of those, and said we must have done something wrong. I wonder what we did wrong except for going to this lying, cheating machinist who took about 7 months to bore and balance our motor to start with. Any opinions?
Rick Costs money to go to school !!!!! Here is the way we install mallory http://i7.photobucket.com/albums/y27...S/MikeM003.jpg |
I agree this guy shouldn't be balancing stuff like that but he is a pretty big liar with a bigger ego. If I knew how to post the pictures it would really show how bad of a job he did. He says it is not his fault and said our tune-up caused the problem. I am out quite a bit of money but I have learned my lesson, and will go to either Sunset racecraft or Ohio crankshaft. This worthless lying machinist over here took about 7 months and charged about as much as those shops I mentioned. We are in a part of the country where good machine work is hard to find. Thanks for your post.
Rick |
Originally Posted by TRChassis
I agree this guy shouldn't be balancing stuff like that but he is a pretty big liar with a bigger ego. If I knew how to post the pictures it would really show how bad of a job he did. He says it is not his fault and said our tune-up caused the problem. I am out quite a bit of money but I have learned my lesson, and will go to either Sunset racecraft or Ohio crankshaft. This worthless lying machinist over here took about 7 months and charged about as much as those shops I mentioned. We are in a part of the country where good machine work is hard to find. Thanks for your post.
Rick |
Originally Posted by hink
Originally Posted by TRChassis
I agree this guy shouldn't be balancing stuff like that but he is a pretty big liar with a bigger ego. If I knew how to post the pictures it would really show how bad of a job he did. He says it is not his fault and said our tune-up caused the problem. I am out quite a bit of money but I have learned my lesson, and will go to either Sunset racecraft or Ohio crankshaft. This worthless lying machinist over here took about 7 months and charged about as much as those shops I mentioned. We are in a part of the country where good machine work is hard to find. Thanks for your post.
Rick http://i7.photobucket.com/albums/y27.../Mauldin12.jpg |
Thanks Carl,
If it saves one person from getting the shaft on a deal like this it will be worth it. Rick |
Re: Mallory Metal flying out of crankshaft
Originally Posted by TRChassis
Just wondering if anyone else has had an externally balanced 4340 crank balanced to internal specs and have the heavy metal fly out of the crank on the 11th pass. The machinist, if you want to call him that welded the piece into one of the normal balance drill holes not sideways on the counterweight like I have seen. Anyway the piece (1.5" long by 1.0" dia.) came flying out at 6,500 RPM through the pan, the diaper caught it but all 8 quarts of oil also exited and the motor seized, and is a total loss (BBC 496). The hole in the pan is almost 2.5". The machinist told me he had done many of those, and said we must have done something wrong. I wonder what we did wrong except for going to this lying, cheating machinist who took about 7 months to bore and balance our motor to start with. Any opinions?
Rick |
It does look to me like he ground it off to the point that nothing except probably a piece of weld like tin foil was holding that part from coming out with all the centrifical force applied to it. Like I said the engine builder has an ego bigger than the moon so he will never admit he messed up but it is obvious he did. I have seen cranks balanced the way he did it but installed and welded properly as you said, he made a mistake but will not admit it. I made a mistake by taking it to him and should have gone out of town for sure. He was a friend but no more, money paid can be recovered but time + lost and track/race time lost can never be replaced.
Rick |
Re: Mallory Metal flying out of crankshaft
Originally Posted by zetagoat
Originally Posted by TRChassis
Just wondering if anyone else has had an externally balanced 4340 crank balanced to internal specs and have the heavy metal fly out of the crank on the 11th pass. The machinist, if you want to call him that welded the piece into one of the normal balance drill holes not sideways on the counterweight like I have seen. Anyway the piece (1.5" long by 1.0" dia.) came flying out at 6,500 RPM through the pan, the diaper caught it but all 8 quarts of oil also exited and the motor seized, and is a total loss (BBC 496). The hole in the pan is almost 2.5". The machinist told me he had done many of those, and said we must have done something wrong. I wonder what we did wrong except for going to this lying, cheating machinist who took about 7 months to bore and balance our motor to start with. Any opinions?
Rick I don't think you would ever press a wrist pin is with .004 press!!!! |
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