A main crank bearing knock has very different symptoms. Cancelling cylinders while its running (pulling wires) will show a piston related problem by eliminating or changing the noise. Since that had no change that eliminated pistons, pins, skirts & rod bearings. Running without belts eliminated the front accessories. Running with torque converter unbolted eliminated the transmission. That only leaves the valve train , or something foreign or loose in there. Now, I've busted a few motor mounts in my time, that was always ***ociated with plenty of heavy foot abuse. You didn't tell us the motor mount part out at first. Once it took 3 weeks for a missed shift to show the effects. Think back what happend
I've found the failure mode on the nylon coated teeth is not due to the nylon, but the chain. The chain stretches, and being a flat link, the teeth don't all line up and begin to chew into the nylon, this causes it to start to crack, eventually the teeth break off and the soft aluminum is exposed. The crank sprocket will also have signs of the steel flat links gouging the teeth. Pulled timing sets out of <30K mile engines with visible slop in them. These flat link nylon coated cam sprocket timing sets are junk. A simple way to check the chain. Pop the distributor cap off. Rotate the crank to 0°. Rotate the crank backwards while watching the distributor rotor. When the rotor just starts to move, STOP Look at the balancer timing tab and note how many degrees it has moved. 0-5° OK >5° Chain stretch >10° Nylon coating gone.
[QUOTE="T'RANTULA";7892118]My friend bought a 86 chevy c10 and it had a clanging noise. We changed and checked everything and the noise wouldent stop. It drove my friend so nuts he started tearing the motor apart and when he pulled the head off there was 13 pennys in the number 6 cylinder! Cleaned the pennys out and no more noise. You would be surprised what things end up in an engine...[/QUOTE] how did this happen?
Kids with a pocket full of pennies walking thru daddy's garage when he ain't looking while he's doing a intake job. When dad gets done and starts it up he can't figure our what went wrong and then sell truck. Or maybe the guy was an ***hole and someone put them in there to get even. Or perhaps the same way stones always got inside someone's hub cap. I have found peanut ****er & jelly sandwiches in a VCR before. However you would think the pennies would jamb up or at least get stuck in the squish and jack something up.
This came out of motor that was running perfectly fine. There was no reason to suspect this. Here's a nylon coated gear. Note the crack at the keyway.
Go to the harmonic balancer and check crankshaft end play by using a pry bar behind balancer,a worn thrust brg. will cause crankshaft movement under load but will subside on coast.First make sure you remove the belt,go to flywheel and with pry bar pull crank to rear to take up any play,then go back to balancer and pull forward to see how much movement is in the crank..006-.010 will not be too much but anything over this could cause a problem.I have a lot of small block cranks in those years have excessive thrust wear.I know you said you took the belt off but I read into it you were checking crank up and down play not front to rear.If you checked front to rear I am sorry to have made a bad post.
Very common problem just as you describe it. I have changed several over the years cracked just like this.
Well a friend and I are going to tear into it. Hopefully next week. I'll post the results of the mystery noise.
Wish I were closer Fred. I'd help ya out. This bums me out to see one of my favorite HAMB cars down.....
Thanks for the offer. I'm just going to pull a "Steve Austin". I'll make it stronger and faster. Might take a while due to funds and time, but it'll get done.
Okay, here's the skinny. I don't have pics, but I found out what the noise was. Bad crank mains. One clyinder was dead. A friend who builds motors listened to it and broke me the news. It was an '84 SBC and just gave out. **** happens. Now the GOOD news. He had a few motors he had already built and I'm going with a 350SBC. Nice cam, fresh heads and ready to run. He gave a great price and I dropped it off today. Should have my T Bucket back Tuesday. So... STRONGER...FASTER... we have the technology! I'll probably upgrade the rearend this fall. Which brings up how addicting hot rods are. I've been chewing off fingernails not being able to drive my rod! Even though it's been raining the last week and I wouldn't have driven anyway.... I MISS MY DAMN HOTROD! I tried explaining this to friends at work (non car guys) and they'll never get it.
In between my last post and now, I had changed the oil, added Marvel Mystery Oil and adjusted the rockers. After running it for a while, I narrowed the sound down to either lifters or worse. It turned out to be my worse thought. You're right, knowing is some form of relief. I was going to have my bud rebuild it, but that didn't make sense over an upgrade.
Nothing worse that suffering Hot Rod Deprivation withdrawals but at least your headed for a full recovery. Enjoy your new found horse power.
I wanted a 350 in the beginning, but didn't have the money for it at the time. So, going this route was going to happen sooner or later.
Say your post in he Tbucketteers site and you said the engine swap will be done by Tuesday !!! WOW !!! Quick change over. But really, how long can it take with a roadster? Anything else gonna be changed? You know, like a tunnel ram or supercharger or something? Actually, with the single quad manifold and 600 cfm Edelbrock it should be dead perfect. Happy trails to you, John
I'm going back with my factory intake and single 4bbl. I wanted a Performer intake, but it's basicly the same thing, just lighter. The 305 was plenty. This is just well built and a fairly fresh build. The new engine is said to have just over 5,000 miles on it. So, it's well broken in. It shouldn't take them too long to swap it. The guy went to get the cam for it when I left.
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