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For full features; Go to 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
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
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
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
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
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
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
adamc44
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
Thank You !!
bobsyourman
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
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:clap:
mrblaackk
