sprocket2005
15+ Year Contributor
- 35
- 1
- Oct 29, 2007
-
Burgettstown,
Pennsylvania
Im having a bad problem and cannot get a reasonable explanation from anyone, my main bearings and crank keep tearing themselves to shreds very quickly after rebuild. (like within 1000 miles) I have had this happen 3 times in a row, and cannot figure out why. The story...
I got the car, when i bought it it had a 7 bolt motor in it and the guy i got it from agreed to have a 6 bolt swap done. I got the car from the garage that did the swap, drove it 70 - 80 miles and the main bearings were shred like nothing anyone has ever seen before. It looked like oil starvation, but i never lost oil pressure. Nobody could figure out what exactly had happened to cause this, it looked like someone drove it down the dragstrip with no oil in it. It was bad. The crank was destroyed, and the rod bearings were messed up too, but they werent as bad. Also, im not sure if it means anything or not, but the thrust bearing was the worst, by far the worst, but they were all bad, torn to hell and back. The oil pan had shreds of the main bearings all over it, but none of them came out in the oil, they looked like metal fish flakes. The only reason i even discovered the problem was because i wanted to replace the leaky oil pan gasket, the car ran fine and pulled strong. I just figured that the guy that built the motor before he dropped it in didnt know what he was doing. So, I went to slowboy racing and a guy that worked there had a motor for sale. A built motor. I bought the motor and the same damned thing happened. I got like 80 - 100 miles on the motor, pulled the oil pan and saw the same kind of "fish flakes" in the oil pan. I was speechless, how could this happen to me?? I just dont get it. A whole different motor, all different parts, and the same problem. The bearings were shredded, crank destroyed, and i felt like total crap. I took the block to my machine shop, had it cleaned profusely, and they rebuilt the motor for me. I picked up the motor from the shop as a rotating assembly already assembled in the block. They used all factory specs for clearances and everything else, so it should have been ready to roll. They also decked the head, replaced the valve guides and valves and assembled the head to the block. All i did was put the motor into the car, put 1000 miles on it and it began to make a knocking/ticking sound. It kinda sounded like a bad set of lifters so i put the revised lifters in it and it still made the same knocking/ticking noise. I wasnt sure what else it could have been making the sounds, the only thing i could think was that it was either a bad wristpin, or a rod bearing. I pulled oil pan, and no fish flakes!! I pulled the rod caps and the bearings had scratch marks, and the mains do too, just enough to feel by fingernail and there is also some kind of whiteish residue on the main bearings, the crank also was scratched, but the wristpins were fine, there was not any play at all to be felt. The valves are not sticking or anything, the rockers are good, and everything else checked out good. I dont know what to do about the ticking, it has gotten louder and it doesnt go away after 3000 rpms, like lifter tick sometimes does. Although i need to figure out what the ticking is, that is not my main concern. I need to know what is going on that my bearings are scratched up, they didnt spin this time, they didnt spin in the other motors either, but they are scratched enough that im gonna have to rebuild. The only thing i can think of is dirty oil, the only way for the scratches/scrapes to get in the bearings is for some kind of dirt or something getting in the oil then getting stuck in the bearings. I dont know how that could be because i literally changed the oil in the 3rd motor every 100 miles, and i would never ever reuse the filter so it got a new one each time too. Every time i changed the oil i either sent it to blackstone labs to be analyzed or screened it myself with a coffee filter to make sure there wasnt anything in the oil. When i sent out the oil to blackstone labs to be anaylzed, they said there was a high level of lead in the oil, which usually means bearing wear, and they also said that bearings dont break in like other engine parts do because they told me that the bearings dont actually touch the crank and there is a thin layer of oil between the bearings and crank that separates and lubricates them. So, the way i see it dirt has to be the problem. But, how would dirt be getting into my oil? Something is tearing the bearings and crank up and i can guarantee it wasnt a dirty assemble. The machine shop that did it is very reputable and i know people who have had other engines built there and never had a problem. Also, every time i changed the oil i would find a small amount of metal particles in the oil, but they were very tiny and so few that i didnt get too excited about it. Maybe im not thinking straight with my hypothesis about the dirt but im out of ideas. Also, if it matters i did NOT beat the living piss out of any of the three motors, yeah ive opened them up but wide open throttle isnt a bad thing for a motor as long as your reasonable about it, and although ive been accused many times by many people for me doing something wrong when driving it to cause my problems im not aware of any driving styles that can tear main bearings apart, because there arent any. Does anyone have any ideas? I cannot afford to keep doing this, financially or mentally.
I got the car, when i bought it it had a 7 bolt motor in it and the guy i got it from agreed to have a 6 bolt swap done. I got the car from the garage that did the swap, drove it 70 - 80 miles and the main bearings were shred like nothing anyone has ever seen before. It looked like oil starvation, but i never lost oil pressure. Nobody could figure out what exactly had happened to cause this, it looked like someone drove it down the dragstrip with no oil in it. It was bad. The crank was destroyed, and the rod bearings were messed up too, but they werent as bad. Also, im not sure if it means anything or not, but the thrust bearing was the worst, by far the worst, but they were all bad, torn to hell and back. The oil pan had shreds of the main bearings all over it, but none of them came out in the oil, they looked like metal fish flakes. The only reason i even discovered the problem was because i wanted to replace the leaky oil pan gasket, the car ran fine and pulled strong. I just figured that the guy that built the motor before he dropped it in didnt know what he was doing. So, I went to slowboy racing and a guy that worked there had a motor for sale. A built motor. I bought the motor and the same damned thing happened. I got like 80 - 100 miles on the motor, pulled the oil pan and saw the same kind of "fish flakes" in the oil pan. I was speechless, how could this happen to me?? I just dont get it. A whole different motor, all different parts, and the same problem. The bearings were shredded, crank destroyed, and i felt like total crap. I took the block to my machine shop, had it cleaned profusely, and they rebuilt the motor for me. I picked up the motor from the shop as a rotating assembly already assembled in the block. They used all factory specs for clearances and everything else, so it should have been ready to roll. They also decked the head, replaced the valve guides and valves and assembled the head to the block. All i did was put the motor into the car, put 1000 miles on it and it began to make a knocking/ticking sound. It kinda sounded like a bad set of lifters so i put the revised lifters in it and it still made the same knocking/ticking noise. I wasnt sure what else it could have been making the sounds, the only thing i could think was that it was either a bad wristpin, or a rod bearing. I pulled oil pan, and no fish flakes!! I pulled the rod caps and the bearings had scratch marks, and the mains do too, just enough to feel by fingernail and there is also some kind of whiteish residue on the main bearings, the crank also was scratched, but the wristpins were fine, there was not any play at all to be felt. The valves are not sticking or anything, the rockers are good, and everything else checked out good. I dont know what to do about the ticking, it has gotten louder and it doesnt go away after 3000 rpms, like lifter tick sometimes does. Although i need to figure out what the ticking is, that is not my main concern. I need to know what is going on that my bearings are scratched up, they didnt spin this time, they didnt spin in the other motors either, but they are scratched enough that im gonna have to rebuild. The only thing i can think of is dirty oil, the only way for the scratches/scrapes to get in the bearings is for some kind of dirt or something getting in the oil then getting stuck in the bearings. I dont know how that could be because i literally changed the oil in the 3rd motor every 100 miles, and i would never ever reuse the filter so it got a new one each time too. Every time i changed the oil i either sent it to blackstone labs to be analyzed or screened it myself with a coffee filter to make sure there wasnt anything in the oil. When i sent out the oil to blackstone labs to be anaylzed, they said there was a high level of lead in the oil, which usually means bearing wear, and they also said that bearings dont break in like other engine parts do because they told me that the bearings dont actually touch the crank and there is a thin layer of oil between the bearings and crank that separates and lubricates them. So, the way i see it dirt has to be the problem. But, how would dirt be getting into my oil? Something is tearing the bearings and crank up and i can guarantee it wasnt a dirty assemble. The machine shop that did it is very reputable and i know people who have had other engines built there and never had a problem. Also, every time i changed the oil i would find a small amount of metal particles in the oil, but they were very tiny and so few that i didnt get too excited about it. Maybe im not thinking straight with my hypothesis about the dirt but im out of ideas. Also, if it matters i did NOT beat the living piss out of any of the three motors, yeah ive opened them up but wide open throttle isnt a bad thing for a motor as long as your reasonable about it, and although ive been accused many times by many people for me doing something wrong when driving it to cause my problems im not aware of any driving styles that can tear main bearings apart, because there arent any. Does anyone have any ideas? I cannot afford to keep doing this, financially or mentally.
