repeated rod bearing failure

Discussion in 'PSI Superchargers Tech Questions' started by PROMOD63, Aug 15, 2020.

  1. PROMOD63

    PROMOD63 Member

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    ok so after 12 years of running the same combo with zero problems last year at wichita we kicked out the 1 and 2 rod when i took it apart i seen what i perceived as a dry start condition that had seized the bearings to the crank, spun them in the rod and eventually broke the rods. send crank back to winberg,got a new set of grp rods, brad fixed the block and we put in pistons i took oil pump apart it looked great so i cleaned and reused it ( wet sum running 16 quarts of brad penn nitro 70 with two lucas oil stabalizer just like the last 12 years ) we took back out and it ran great but had a tranny leak so i was freshing the engine with 4 passes on it just to be safe , when i got to the # 2 rod the bearing was black like lack of oil and it had spun about half way around. it tore the rod up but the crank looks good a little metal on it and a couple of scratches, the rest of the bearings upper and lower i could put in a box and sell them as new. anyone have any ideas? this had to have been in the shut down due to the minimal amount of damage,or could the mag be missfiring on that hole ? thanks in advance
     
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  2. TOL

    TOL Active Member

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    Top half or bottom half? Chase all the oil passages?
     
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  3. Mike Canter

    Mike Canter Top Dragster
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    If you have a crank trigger make double sure that the crank trigger cable is nowhere near the coil wire or a plug wire. Don’t bundle it in with other wires. High voltage spark can be picked up by the crank trigger cable and randomly fire the mag. This can destroy rods and bearings.
     
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  4. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    How is the oil pressure in shutdown? I have seen a lack of oil cause the exact problem you describe.
     
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  5. jay70cuda

    jay70cuda Well-Known Member

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    I've seen lack of oil psi in the shut down do this. Hell I did it 3 times before I bought a moroso dry sump tank. I never ran Lucas oil before last season and gave it a try. My bearings looked like shit. Weak oil psi at best. Changed the oil to different brand and all my problems went away. Not saying anything bad about Lucas but I had a sponsored guy tell me the only reason he runs it because it's free. He has to dump it every night because it breaks down too quickly.
     
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  6. PROMOD63

    PROMOD63 Member

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    ok so i think i found it, the car has always has had a issue with the oil pressure dropping off around 2.0 but never caused a issue so i never really addressed it bearings always looked good. This little monster reared its head when we went over to wichita and raced their track is much longer than the one i run at normaly so i wasnt as concerned about a quick shut down, this must have been the straw that broke the camels back because this never happened at the local track. so now i got to fix the problem of the car pumping the oil to the top which is what i am pretty sure it does i have looked through old runs and it has been doing this for years. we run 16 qts brad penn nitro 70 with two lucas stabilizers sound like enough? also they tell me that the rocker stands ( stage 5 red stands ) should have oil restrictions in them or in the block if preferred but we dont have any ( but i havent replaced a rocker in 10 years also ) is these restrictors the answer ? more oil ? on just make sure to hit the kill switch at the stripe
     
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  7. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    Are you running the same suction line you have always run? Is it just a standard braided hose or is it reinforced? It could be collapsing.

    How old is the oil pump? Maybe it is losing clearance and going away.

    Restrictors will help, but if you had no problems for years without the restrictors, I would think the problem is somewhere else....
     
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