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another flat cam

Discussion in 'The Hokey Ass Message Board' started by LOWLYDE, Jun 6, 2011.

  1. Da Tinman
    Joined: Dec 29, 2005
    Posts: 4,226

    Da Tinman
    Member


    NO, tried it 3 times, never made it more than a couple months without having a death klank in the bottom end. 2x it was a rod, 1x it was a main.

    thankfully they were just universal donors and werent anything special.
     
  2. Heres a little experiment for you. After you remove the old flat cam, sweep a little spot in the garage nice and clean. Now take a angle grinder 4 1/2" or 7" doesn't matter. Use say a 40 grit flap wheel and have a seat and purposely grind down a good remaining lobe off the cam. Now sweep the grindings up into a pile, and ask yourself, " would I put this into the oil in a good running engine? " I'm not trying to be a smart ass, actually trying to make a good point for anyone reading this. Yes the filter will catch some of the metal, but some will go right through the oil pump first, { alone this is a problem }, and then into the main bearings and then into the rod bearings and finally all through the cam and bearings and valve train.
     
  3. mickeyc
    Joined: Jul 8, 2008
    Posts: 867

    mickeyc
    Member

    Point taken...
     
  4. donkeyfarm
    Joined: Mar 30, 2010
    Posts: 134

    donkeyfarm
    Member

    I called Crane after my cam went flat. The tech said 1 out of every 200 tappet cams will go back due to lack of additives in new oils. I run Shell Rotella 15-40 because thats what our tractors and trucks run.
     
  5. Thanks for understanding mickeyc, I was really trying to make a point. Yes there are people that get away with not tearing down after smoking a cam, my advice is consider yourself lucky and ahead of the game, and tear it down and fix it right. In the long run, it will always be cheaper.
     
  6. Novadude55
    Joined: Nov 10, 2009
    Posts: 2,352

    Novadude55
    Member
    from CA

    I've seen bent pushrods, and or noisy rockers that you cant quiet down no matter how tight you adjust them
     
  7. Novadude55
    Joined: Nov 10, 2009
    Posts: 2,352

    Novadude55
    Member
    from CA

    Yes, 350, chevy truck, had just bought it, guy said it had a problem and he couldnt figure it out,, so got it running and after bending two pushrods, and another rocker that wouldnt tighten, I tore it down, confirmed flat lobes, and since it was a ranch truck, not a daily driver, I installed a stock cam I already had, bought new lifters, put it back together, used assembly lube on cam and lifters, adjusted the valves, changed the oil and filter, did the 15-20 min startup at 2000 rpm, still runs great. maybe i shoulda tore it down, but i didnt.
     
  8. bob myers
    Joined: May 24, 2007
    Posts: 302

    bob myers
    Member

    Here`s my story: built sbc 383, flat tappet comp cam. Broke it in properly, switched to mobil 1 at 1500 miles drove it 16,000 miles over 8 years and lost a cam lobe.
    Last year pulled the offending cam and lifters, broke it again,switched to dino oil with a comp cams zinc additive......runs great again, good oil pressure, 25lbs idle, 50 lbs down the rod when warmed. Point is, you might get lucky too.
     
  9. TMoney
    Joined: Dec 27, 2006
    Posts: 804

    TMoney
    Member

    Backfiring out of the carb means an exhaust valve isn't opening... i.e. flat lobe. When you pull the cam make sure sure the cam bearings are good as well.
     
  10. LOWLYDE
    Joined: May 3, 2008
    Posts: 121

    LOWLYDE
    Member

    thanks for all the info, Im going to try my luck just doing a cam swap, its an OT truck (not a daily driver) I already have a cam and lifters so what the hell ill give it a shot, Its a throw away 350 anyways, if it wipes out o-well. I would never chance it with a rare or expensive block but i paid 500 dollars for a complete 83 chevy 4x4 (Rolled) that i parted out and made money on, I will forsure try it!...Thanks guys!!
     
  11. chop32
    Joined: Oct 13, 2002
    Posts: 1,077

    chop32
    Member

    Chances are that you may have already hurt the engine.
    I lost an exhaust lobe on a solid lifter cam in my 427. Lobe was round, lifter was dished.
    I didnt see any sign of metal when I changed the oil, so I swapped cams, not even thinking about where all that metal went.
    Broke in new cam with no problems and drove the car around for about a week until I jumped on it and heard the bottom end start to rattle.
    Wiped out all the rod bearings and scored the crank!
    Since its a throw away engine, go for it, you might get lucky!
    If it were something you cared about, Id say tear it down and check/clean everything.
     

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