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Anyone have any ideas why the case bushing would back out on my engine? Bushing backed out, went through the timing gear, jumped time and valves hit pistons. No loss in oil pressure. It's the factory bushing which was all within spec a few years ago when I replaced crank, which i Have about 7500 km on. Oil pump is good, rod bearings and all journals are still in good condition. Was never run low on oil. This is the first time I've heard of this, other than a poor install of the hot rods bushings.
This is the end for me. Full part out in progress unfortunately. The TRP Standard Bore was a blast for many Miles, and the 820 was an absolute monster.
 

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I never heard of that either, or even remember reading anything about that type of failure.
 

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I never heard of that either, or even remember reading anything about that type of failure.
Yeah, I really don't understand why it failed. I would love to hear anyone's speculation as to why this would happen.
The Crank and rods are still in perfect condition.
 

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Ok..just speculation. The bushing's surface and the crank's bearing surfaces look good but the thrust surface on the crank looks like it's been to war on more then one occasion. So..I speculate..the end play was under spec for the added heat that would be generated to the rods and crank from the added performance kit and when at full expansion it went to zero a time or two scaring the two surfaces thrust. Then.. the last time it did it, the primary was at or near full shift-out and under high power and RPMs and it partly seized on those two surfaces and partly spun the bushing. With that much thrust against it, it has no choice but to slide out as it spun. Then it caught the chain and the rest... is history.
 

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That sucks, man. Bad luck I guess. Definitely not a common thing with these engines.
 

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Ok..just speculation. The bushing's surface and the crank's bearing surfaces look good but the thrust surface on the crank looks like it's been to war on more then one occasion. So..I speculate..the end play was under spec for the added heat that would be generated to the rods and crank from the added performance kit and when at full expansion it went to zero a time or two scaring the two surfaces thrust. Then.. the last time it did it, the primary was at or near full shift-out and under high power and RPMs and it partly seized on those two surfaces and partly spun the bushing. With that much thrust against it, it has no choice but to slide out as it spun. Then it caught the chain and the rest... is history.
I'd buy that explanation.
 
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