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377 scorpion borken crank

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Old 07-08-2009, 02:26 PM
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Default 377 scorpion borken crank

my buddys 377 scorpion with 65 hours broke the crank, is this a problem with these motors.

Last edited by rssteiny; 07-08-2009 at 02:53 PM.
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Old 07-08-2009, 02:38 PM
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Originally Posted by rssteiny
my buddys 322 scorpion with 65 hours broke the crank, is this a problem with these motors.
The 377 Scorpion is a fantastic motor with expensive parts. The crank is a Lunati piece. Not sure what caused the failure but I'd guess there might be a vibration issue. How's the prop look?
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Old 07-08-2009, 03:26 PM
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Check the harmonic balancer. Put on a fluid damper with the new crank.

That sucks! Hope he gets it back together quick.
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Old 07-08-2009, 04:32 PM
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I broke a crank once. It was when my 454 had cast internals. I had made a few mods and made about 400 HP, I thought is was too much HP for the cast crank. I think it was more likely a oiling issue. I am not sure if that relates to your buddies case. Merc Racing should have the oppropriate oiling system from the factory. That engine comes with all forged internals, should be very reliable.
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Old 07-08-2009, 08:20 PM
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rs,
Just curious where it broke ? Snout ? In the middle ? Etc Real unusual for a steel crank to actually break without something causing it.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md
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Old 07-08-2009, 09:52 PM
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Was he running a blower?
Incorrect setup of blower drive can break a crank.
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Old 07-09-2009, 01:52 AM
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Its also the same engine that showed 6" overfull on the dipstick. Its all related and will have to come apart and then try to figure out what caused what.
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Old 07-09-2009, 07:16 AM
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The 6" overfull was after it shut down i think he will find it broke the block and water poured in at the time it broke, did not get milky because the motor was not running and never mixed with the oil. no blower just stock motors, ill keep u posted when it gets tore down.

thanks guys
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