Balance issues

-
Duster 72

Duster 72

Well-Known Member
Joined
Dec 24, 2019
Messages
73
Reaction score
72
Location
Thompson falls Montana
Ok guys big F!#cking issue and not exactly sure what happened. Had an engine assembled for me for the first time at the machine shop. (Didn't have time to do it myself) Broke motor in and it failed. Had rotating assembly balanced and it burned and spun 3 main bearings from torque converter side forward! Did the shop screw up or is this my doing? Cam bearings didn't fail it ran for 15 minutes?!!!$$$ super confused main bearings were bright blue and black. Insight please? Can I reuse the pistons and rods in another engine?
 
Did it lose oil pressure? What was the oil pressure? Were you breaking in the cam or idling it? Was it clean inside? Was the bearing clearance correct? Did they write down the bearing clearances when they assembled it? How do the rod bearings look? Measure clearances of the good bearings that are left.

sounds like the wrong size main bearings.

what engine is this?
 
were all the bearings installed properly, ie cam bearings lined up? all galley plugs installed? That's bad news.....
 
You gave no build details so we have to guess. I will guess big. Maybe it was an aftermarket crank with radiused journals and they failed to use properly clearanced bearings.
 
Its a 77 block 440 bored 30 over 10.1 compression cast crank they didn't supply any paper work besides build. Full engine break in. Factory crank they turned .10 bearings were right size just never seen before. Found cotter pins in oil pan they assembled 100% of motor minus carb
 
Duster 72 said:
Its a 77 block 440 bored 30 over 10.1 compression cast crank they didn't supply any paper work besides build. Full engine break in. Factory crank they turned .10 bearings were right size just never seen before. Found cotter pins in oil pan they assembled 100% of motor minus carb
Click to expand...
I guessed wrong.
Do you have any pictures? Is the tip broke off the intermediate shaft? If not, stick it in the oil pump and see if you can spin the pump.
Did you prime the oil system before startup? What was oil pressure during priming and while it was running?
Were the cotter pins you found damaged, like they got into something in the engine?
 
Bobzilla said:
I guessed wrong.
Do you have any pictures? Is the tip broke off the intermediate shaft? If not, stick it in the oil pump and see if you can spin the pump.
Did you prime the oil system before startup? What was oil pressure during priming and while it was running?
Were the cotter pins you found damaged, like they got into something in the engine?
Click to expand...
 
Unfortunately I don't have any pictures the motor sounded fine oil psi on mechanical gauge was 70. Motor died at about 15 minutes on its own pulled drain plug and nothing but strings and glitter mixed with oil came out. I tore the whole thing apart. Oil pump turns fine. The only parts of the cotter pins I could recognize were melted looking. But the size you would use on a pitman arm! And the filler they used on the crank appears to be falling out from balancing it
 
If the thrust is gone from the converter side that’s on you. That means you didn’t get the converter all the way into the transmission and it knocked the thrust out.

Don’t feel bad. I’ve seen it so many times I can’t count hem all any more.
 
Last edited:
I just love it when these members ask for help then never follow up. He has been on X number of times and can’t even stop in with an update of any kind good or bad. Kim
 
oldkimmer said:
I just love it when these members ask for help then never follow up. He has been on X number of times and can’t even stop in with an update of any kind good or bad. Kim
Click to expand...
He is probably in mourning at the same time kicking himself...
 
Duster 72 said:
Ha ha guys been busy. Not ignoring anyone motor is disassembled sitting at another machine shop.
Click to expand...
For anyone still following thread. Got motor back from shop they said that they installed the wrong size main bearings. The crank was garbage. Relined bored block fresh crank. Beginning the assembly process
 
Duster 72 said:
For anyone still following thread. Got motor back from shop they said that they installed the wrong size main bearings. The crank was garbage. Relined bored block fresh crank. Beginning the assembly process
Click to expand...
I had a shop put the wrong bearings into a 225. There was so much main clearance that the engine sounded like it had rocks in it. Ugh.
 
Dam, it sucks to have to use a different shop and pay everything out of pocket. Make sure u let them know they screwed up. Kim
 
Last edited:
oldkimmer said:
Glad to hear they stepped up to the plate and fixed it for u. Kim[/QUOTE
Thanks guys
Click to expand...

20220304_153139.jpg


20220304_153142.jpg


20220305_135359.jpg
 
I bought an Eagle cast stroker crank and when I put the first main cap on, I tried to turn the crank and it was locked up solid. Checked the cap, it wasnt even seated. Pulled the cap and looked at the bearings, found the crank was FORGED and had fillet radii onthe mains and the bearings were not compatible. Bad thing was the bearings didnt fit, good thing was they sent me a forged crank instead of a cast! :D
 
I'm glad you found the problem and are getting it fixed. I'm not that familiar with big blocks, cotter pins?
 
You must log in or register to reply here.
-

Back
Top