Broken Camshaft

Discussion in 'Engine Topic' started by Kjdavis93, Jul 30, 2012.

  1. Kjdavis93

    Kjdavis93 Veteran Member

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    I would like to know if anyone could tell me what they think was the cause. Fist off its a 350 .040 over. I sold the car last week an hour after he took possesion he called and told me the engine locked up.
    I installed the cam around 3 weeks ago. I used the comp cam additive, coated the cam with assembly lube. I ran the engine at just above 2000 rpm's for around 35 minutes. The car was running excellent.
    Today I went to the guy's house to evaluate what happened. He told me had the engine at 3000 rpm's and went to shift from 2nd gear into 3rd that the motor fluttered and died. Pulled the valve covers off and no push rods for the number 1 or number 2 cylinder. Removed the intake and it looks like a small bomb went off. Busted lifters missing lifters and the pushrods have slid down the lifter bores and were jammed up with the crank. I removed the timing chain cover and the front piece of the cam was able to be pulled out of the block by the cam gear. It busted in half after the fuel pump lobe and before the number 1 and to cylinders.
    I was just wondering if anyone knows what maybe caused this.
    Thanks
     
    Last edited: Jul 30, 2012
  2. muscl car

    muscl car Veteran Member Lifetime Gold Member

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    alot of things can cause a can to snap in half ,sounds like your issues started with cyls #1 & 2

    sound like a interference issue like valve spring binding from to much lift ,this can cause damage like you found .also a loose cam gear on the timing chain can do the same damage
     
  3. Kjdavis93

    Kjdavis93 Veteran Member

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    It has a comp cams locking plate still intact, and was a hydraulic flat tappet cam with a 482 grind, so could to much lift still be possibile?
     
    Last edited: Jul 30, 2012
  4. 71RS/SS396

    71RS/SS396 Veteran Member

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    I had that exact same thing happen in my youth when I missed a shift and over revved the engine, the water pump and the intake and carb were all that was salvageable from the engine. I'd be skeptical that he wasn't beating the crap out of the engine.
     
  5. Damon

    Damon Veteran Member

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    Cams usually break when a connecting rod comes apart and slams into it. You can do all sorts of valvetrain carnage from "flat stacking" springs and bending pushrods, lifters hopping out of their bores shortly thereafter, etc. But snapping a cam is usually a case of murder, not suicide.
     
  6. red78z

    red78z Veteran Member

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    Unless you cover the replacement or repair costs , hes gonna think ur a douche , but as stated above id be thinking that he was pounding on it when it let go, but how do you prove it? Also remember sales are final and buyer beware. Youre in a tough spot
     
  7. soco200p

    soco200p Veteran Member

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    I agree it sounds like the guy was beating the crap out of the car and over-revved it.
     
  8. hhott71

    hhott71 R.I.P 11/19/18 Lifetime Gold Member

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    Too much lift, coil bind etc would have happened during the break-in (well before) not hours of run time later.

    That had it 3,000 and tried to shift. He had it past 6500 and floated the valves, broke a rod etc.

    When I broke a rod I had a 3 pc camshaft, missing lifters etc. That's how it looks when an engine grenades inside.


    The car was sold AS IS, and he ABUSED IT!
     
  9. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    ^+1
    The evidence is indiciative of excessive RPM management.
    This would be the fault of the driver, not seller of the car or engine builder.
    (Unless you gave the guy a written warranty which covered excessive RPM abuse.)
     
  10. stroked383

    stroked383 Veteran Member Lifetime Gold Member

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    My vote is also that the new owner was probably "enjoying" his new purchase. We have all done it, that is why we built our cars. Dude was probably checking it out to see what it had, after all he just bought a 2nd gen with a 350. That's the 1st thing I did when I bought mine was get on it a bunch to see what I had gotten myself into. Its the luck of the draw, my opinion is that when you buy something like this, you take the good with the bad. If you break it you better know how to fix it or don't cry about it when it does break
     

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