Small Block & Big Block Chevy Specific - Problem 383 WTF!!

So a while back i decided to start my winter project... putting a 383 stroker into my project car. Before i stuck it in the car i took it to the machine shop to check all the clearances, rods, caps, other small things. Its a 350 block with a 400 crank in it... so any way i put it together every thing went smooth. Put it in the car and there is noise coming from the bottom end. Sounded like a rubbing type sound. Drain the oil and i get a lot of copper.

After i take it back out i found that the rear thrust bearing is completely wiped out. Take it back to the machine shop and all they can say it that the torque converter was pushing on the crank, or there was no end play. Now i checked that and there was about 6 thousands worth of play before i put it in the car. Also when i bolted the converter up there was about 1/4 inch between the fly wheel and torque converter which is normal.

So i get the block back put the new bearings in it and drop it in with no trans attached. Start it up let it run same noise drain the oil same shit comes out. I am at a loss for words as what it could be. Do i have a bad Block? Crank? i really don’t want to spend the time or the money to do this a thrid time. Any one have any ideas?? 383 :bigun2:

OK, is it on the front side of the trust bearing or rear? and is it on the top bearing or is it on the bearing thats on the cap that your rubbing on?? i had a problem once almost the same your having but the problem was that when i put the cap on it wasnt quite allinged with the upper bearing and it wore the bearing on the cap down untill it had the clearence it needed, when i put it back on the 2nd time i made sure it was nice and alinged before i finnaly torqued it down. if you had 6 grand of end play you shouldnt be having a problem, and i owuldnt think it would make much noise because of this you might have other problems have you checked the other bearings??

One question...Did you get the block clearenced for the larger stroke?

If not then that copper color you see is shavings from the side of the block from the crankshaft rubbing against the side wall.

OK, is it on the front side of the trust bearing or rear? and is it on the top bearing or is it on the bearing thats on the cap that your rubbing on?? i had a problem once almost the same your having but the problem was that when i put the cap on it wasnt quite allinged with the upper bearing and it wore the bearing on the cap down untill it had the clearence it needed, when i put it back on the 2nd time i made sure it was nice and alinged before i finnaly torqued it down. if you had 6 grand of end play you shouldnt be having a problem, and i owuldnt think it would make much noise because of this you might have other problems have you checked the other bearings??

It was on the rear thrust bearing. It was the whole bearing that was worn. From the machine shop told me, if i would have kept running the car i would have wiped out the crank. I guess when there is pressure on the thrust it starves the motor for oil, which is true in my case cuz it started to take out 7 & 8 rod bearings. As far as alignment i torqued every thing down and the crank spun fine so i dont get it.

One question...Did you get the block clearenced for the larger stroke?

If not then that copper color you see is shavings from the side of the block from the crankshaft rubbing against the side wall.

Yes the block was check for clearence and it was fine accodring to the machine shop.

So a while back i decided to start my winter project... putting a 383 stroker into my project car. Before i stuck it in the car i took it to the machine shop to check all the clearances, rods, caps, other small things. Its a 350 block with a 400 crank in it... so any way i put it together every thing went smooth. Put it in the car and there is noise coming from the bottom end. Sounded like a rubbing type sound. Drain the oil and i get a lot of copper.

After i take it back out i found that the rear thrust bearing is completely wiped out. Take it back to the machine shop and all they can say it that the torque converter was pushing on the crank, or there was no end play. Now i checked that and there was about 6 thousands worth of play before i put it in the car. Also when i bolted the converter up there was about 1/4 inch between the fly wheel and torque converter which is normal.

So i get the block back put the new bearings in it and drop it in with no trans attached. Start it up let it run same noise drain the oil same shit comes out. I am at a loss for words as what it could be. Do i have a bad Block? Crank? i really don’t want to spend the time or the money to do this a thrid time. Any one have any ideas?? 383 :bigun2:

Most of the time when this happens it's the transmission pushing forward on the crank. If you started the motor without the trans hooked up you have some other problem.

Did you have the block align honed? What where your main bearing clearances and how did you check them? The crank could be bent, also when you checked the crank thrust do you have .006 of free movement or do you have .006 clearance with pressure on the crank. If you want to give me a call I'd be happy to go over this with you. Maybe we can figure it out over the phone.

Harold
512-257-0222

Most of the time when this happens it's the transmission pushing forward on the crank. If you started the motor without the trans hooked up you have some other problem.

Did you have the block align honed? What where your main bearing clearances and how did you check them? The crank could be bent, also when you checked the crank thrust do you have .006 of free movement or do you have .006 clearance with pressure on the crank. If you want to give me a call I'd be happy to go over this with you. Maybe we can figure it out over the phone.

Harold
512-257-0222

Thanks for your time yesterday on the phone ill let you know when i get it apart what the verdict is, i dont think it is gonna be good.