Car Forums  

Go Back   Car Forums > Technical Discussions > Repairs & Maintenance
FAQ Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-22-2008, 06:31 AM   #1
bobsyourman
CF Newbie
 
Join Date: Apr 2008
Posts: 5
455 spun rod bearing? I think?

Well i have this 455 that was told it had a spun rod bearing or 2! Was wondering what i can do to repair this? I am an amatuer to rebuilding motors but do know my way around the inside of a motor. Correct me if im wrong,but i am thinking i can disassemble the rods from the crank, get the crank ground and replace the old bearings with a different size to fit the new crank diamiter. Was thinking i could hone the cyilindr walls and put in new rings while i was at it but replace with the old rods and pistons. I realize im making it sound fairly simple to do , but thats what i can do with what i got. Or am i totally off the mark here? All input would be valued as i need this back in my boat asap for summer.
Thanks,Bob
bobsyourman is offline   Reply With Quote
Old 04-22-2008, 10:50 PM   #2
newyorker
MXman
 
newyorker's Avatar
 
Join Date: Nov 2005
Location: Philly
Posts: 5,291
Quote:
Originally Posted by bobsyourman
Well i have this 455 that was told it had a spun rod bearing or 2! Was wondering what i can do to repair this? I am an amatuer to rebuilding motors but do know my way around the inside of a motor. Correct me if im wrong,but i am thinking i can disassemble the rods from the crank, get the crank ground and replace the old bearings with a different size to fit the new crank diamiter. Was thinking i could hone the cyilindr walls and put in new rings while i was at it but replace with the old rods and pistons. I realize im making it sound fairly simple to do , but thats what i can do with what i got. Or am i totally off the mark here? All input would be valued as i need this back in my boat asap for summer.
Thanks,Bob
IIRC, you replace rod bearings by dropping the oil pan and getting to them that way, otherwise im not sure...if you want to replace pistons and rods, thats gotta be done from the top of the engine, so prepare to lift the heads as well. You are looking at a lot of time and money for a full build, bearings, not so much.
newyorker is offline   Reply With Quote
Old 04-23-2008, 12:19 AM   #3
bobsyourman
CF Newbie
 
Join Date: Apr 2008
Posts: 5
Yes i realize that but lets say that the crank was reground before this happend. Wouldnt i use a different size bearing on the crank.Or once i got the oil pan off would i be able to tell if infact the crank was ground wrong or ground to much for the bearings that were used in there? Im not sure about how or why you would have a crank ground other than for balancing purposes? I guess this sounds stupid(as i am a novice in this aspect of engine rebuilding) but is it comon to have a crank reground at the points where the connecting rods attach to it with the bearings. And if so would i mic it and get bearings to fit the crank size or just put stock size bearings in it? I am assuming i would see something amis if infact the crank was ground and the stock bearings had a mi-nute gap because of this? Or am i an idiot and am i way off the mark here? lol !
Thanks,Bob
bobsyourman is offline   Reply With Quote
Old 04-23-2008, 12:24 AM   #4
newyorker
MXman
 
newyorker's Avatar
 
Join Date: Nov 2005
Location: Philly
Posts: 5,291
Quote:
Originally Posted by bobsyourman
Yes i realize that but lets say that the crank was reground before this happend. Wouldnt i use a different size bearing on the crank.Or once i got the oil pan off would i be able to tell if infact the crank was ground wrong or ground to much for the bearings that were used in there? Im not sure about how or why you would have a crank ground other than for balancing purposes? I guess this sounds stupid(as i am a novice in this aspect of engine rebuilding) but is it comon to have a crank reground at the points where the connecting rods attach to it with the bearings. And if so would i mic it and get bearings to fit the crank size or just put stock size bearings in it? I am assuming i would see something amis if infact the crank was ground and the stock bearings had a mi-nute gap because of this? Or am i an idiot and am i way off the mark here? lol !
Thanks,Bob
Not too sure on that one. You could take the bearings off and just see what size they are and go from there...never taken a motor apart, wait for Giant or Dodger to come and shed light on this.
newyorker is offline   Reply With Quote
Old 04-23-2008, 02:33 AM   #5
thefonz
CF Addict
 
Join Date: Nov 2004
Posts: 250
Quote:
Originally Posted by bobsyourman
Yes i realize that but lets say that the crank was reground before this happend. Wouldnt i use a different size bearing on the crank.Or once i got the oil pan off would i be able to tell if infact the crank was ground wrong or ground to much for the bearings that were used in there? Im not sure about how or why you would have a crank ground other than for balancing purposes? I guess this sounds stupid(as i am a novice in this aspect of engine rebuilding) but is it comon to have a crank reground at the points where the connecting rods attach to it with the bearings. And if so would i mic it and get bearings to fit the crank size or just put stock size bearings in it? I am assuming i would see something amis if infact the crank was ground and the stock bearings had a mi-nute gap because of this? Or am i an idiot and am i way off the mark here? lol !
Thanks,Bob

If you have to ask these questions, I highly doubt you would be able to tell anything. If you have the crankshaft turned, the machine shop can sell you the right size bearings
thefonz is offline   Reply With Quote
Old 04-23-2008, 03:11 AM   #6
bobsyourman
CF Newbie
 
Join Date: Apr 2008
Posts: 5
So because i dont know about turning a crank and crank bearing sizes you are saying you dont think i can do it? You would be surprised what i have accomplished with a little guidance its not rocket science man ? Trying not to offend the few good mechanics im sure are in here,any monkey can turn a wrench! Monkey !I just need to be pointed in the right direction! If i need to take out the crank and take it to a machine shop then just say so with out the smart ass remarks.
With that being said anyone else want there 2 cents worth for a man with a few questions about this.I would appreciate it.
Thanks.
bobsyourman is offline   Reply With Quote
Old 04-23-2008, 04:01 AM   #7
adamc44
CF Freak
 
adamc44's Avatar
 
Join Date: Jul 2005
Location: west portsmouth ohio
Posts: 775
you can pull the crank and get it checked out by a machine shop. they will set it up and get you the correct bearings in a rebuild kit. you can reuse your rods, but may be better off getting new pistons since youll have it apart already. cylinders might need bored out too. if your going to tear it down that far anyways, might as well have it hot tanked, new cam, lifters
__________________
AMERICA: LOVE IT OR LEAVE IT

http://www.myspace.com/adamc44

adamc44 is offline   Reply With Quote
Old 04-23-2008, 04:26 AM   #8
thefonz
CF Addict
 
Join Date: Nov 2004
Posts: 250
Quote:
Originally Posted by bobsyourman
So because i dont know about turning a crank and crank bearing sizes you are saying you dont think i can do it? You would be surprised what i have accomplished with a little guidance its not rocket science man ? Trying not to offend the few good mechanics im sure are in here,any monkey can turn a wrench! Monkey !I just need to be pointed in the right direction! If i need to take out the crank and take it to a machine shop then just say so with out the smart ass remarks.
With that being said anyone else want there 2 cents worth for a man with a few questions about this.I would appreciate it.
Thanks.

I didn't say you couldn't do it. Don't be such a hot head. I doubt you will be able to tell, (with the lack of knowledge in this) or that you will be able to see if the crankshaft needs turnning. It's not like looking at a brake rotor that is scored all to hell. I'm trying to guide you in the right direction. Pull the crank or anything else you want and r&r. But take the crankshaft to a machine shop. If you decide to do this project on your own, don't be so quick to talk junk to someone trying to help you.
Don't forget to mark the connecting rods and bearing caps so they go back in the same place and same order. It may not be rocket science, but it is more than turning a few bolts and just swaping things out.
Cheers and good luck with your project.
thefonz is offline   Reply With Quote
Old 04-23-2008, 05:09 AM   #9
bobsyourman
CF Newbie
 
Join Date: Apr 2008
Posts: 5
Thank You !!
bobsyourman is offline   Reply With Quote
Old 04-24-2008, 09:25 AM   #10
bobsyourman
CF Newbie
 
Join Date: Apr 2008
Posts: 5
Question Ok New Hope!!!

Ok, For starters i would like to apologize to thefonz! I guess i took your first post as a kind of negative response toward my problem!
And i shouldn't have. I thank you for taking the time to respond to my issues and leave your thoughts. That is why im hear in the first place and sometimes if you dont hear what your expecting from someone,it can be takin the wrong way. And i think im guilty of that,im sorry.
BUT WAIT THERES MORE !!!!!!!

I pulled the pan and---
There is a metal type of guard (or plate)that bolts right under the oil pick-up screen. Well above if the motors right side up.Now as i look at it i see that 2 points of connection is supposed to bolt
down under the nearest main crank journal bolts and the other single bolt,witch is actually a duel purpose bolt(holding down the oil pump and then another nut goes on top to hold down this plate). Well only the duel purpose bolt was bolting this plate down and the front 2 someone attempted to tack weld it to the main journal bolt heads!(it didnt hold) !!!!!
So this plate, im sure was rattling around in there making a ton of noise as it scraped along when the crank was rotating around with the engine running!
Dont you think ???????????????(what i really need is a good Oldsmobile guy that can attest to this plate)
But i did see a slight (very slight) gap in the center main crank bearing and not in any others, But the gap was the same on both sides? It looks like you could put a hair in between there but not much else?
What do you guys think? Should i bolt the plate down properly and put it back together?(not very expensive)
Or pull the crank anyway and have it checked?(possibly very expensive)

WEIRD HUH??
Thanks.
bobsyourman is offline   Reply With Quote
Old 05-11-2008, 02:05 AM   #11
mrblaackk
CF Newbie
 
Join Date: May 2008
Posts: 3
My opinion, if the cranks been turned

It's been reduced in size. You would have to compensate for what has been taken off. Maybe, if you're brave have spun area machined again and use an oversized race. To compensate for missing metal only for the brave of heart
mrblaackk is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Forum Jump



All times are GMT +1. The time now is 08:25 AM.

Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2002 - 2011 Car Forums. All rights reserved.