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-   -   whats ur thoughts on these rod/main bearings (http://www.hotrodders.com/forum/whats-ur-thoughts-these-rod-main-bearings-224513.html)

Project89 09-29-2012 08:43 PM

whats ur thoughts on these rod/main bearings
 
http://sphotos-a.xx.fbcdn.net/hphoto...30165075_n.jpg

http://sphotos-a.xx.fbcdn.net/hphoto...27125479_n.jpg

http://sphotos-a.xx.fbcdn.net/hphoto...83486772_n.jpg

http://sphotos-b.xx.fbcdn.net/hphoto...60716417_n.jpg

the worst main

http://sphotos-a.xx.fbcdn.net/hphoto...69160989_n.jpg

http://sphotos-b.xx.fbcdn.net/hphoto...37876135_n.jpg

and the main bearing from above pics

http://sphotos-b.xx.fbcdn.net/hphoto...27769977_n.jpg


this is my friends 3.1L v6 with a turbo about 120k on the engine and he managed to break the 2nd ringland on the number 6 pistons.

he just bought a house so he wants to get this back together as cheap as possible, as it would be a waste to spend the money on the 3.1 when he can build a 3.4L for the same money.which wont be till next year since he just bought a house.

so the plan is new ring set, 6 new hyper psitons and do a quick flexhone job to get the rings to seat.

my thoughts on the bearings are just to reuse the originals since they are worn in anyplace that needs clearance and they dont look bad.


what do u guys thing would u resuse them or would u slip new bearings in there even though the crank has some slight scoring from dirt passing threw.

the engine ran perfect, had great oil presure before it was torn down, it just had low compression in num 6 as the second ring was broke due to the cracked ringland

ap72 09-29-2012 09:08 PM

Quote:

Originally Posted by Project89 (Post 1594962)
http://sphotos-a.xx.fbcdn.net/hphoto...30165075_n.jpg

http://sphotos-a.xx.fbcdn.net/hphoto...27125479_n.jpg

http://sphotos-a.xx.fbcdn.net/hphoto...83486772_n.jpg

http://sphotos-b.xx.fbcdn.net/hphoto...60716417_n.jpg

the worst main

http://sphotos-a.xx.fbcdn.net/hphoto...69160989_n.jpg

http://sphotos-b.xx.fbcdn.net/hphoto...37876135_n.jpg

and the main bearing from above pics

http://sphotos-b.xx.fbcdn.net/hphoto...27769977_n.jpg


this is my friends 3.1L v6 with a turbo about 120k on the engine and he managed to break the 2nd ringland on the number 6 pistons.

he just bought a house so he wants to get this back together as cheap as possible, as it would be a waste to spend the money on the 3.1 when he can build a 3.4L for the same money.which wont be till next year since he just bought a house.

so the plan is new ring set, 6 new hyper psitons and do a quick flexhone job to get the rings to seat.

my thoughts on the bearings are just to reuse the originals since they are worn in anyplace that needs clearance and they dont look bad.


what do u guys thing would u resuse them or would u slip new bearings in there even though the crank has some slight scoring from dirt passing threw.

the engine ran perfect, had great oil presure before it was torn down, it just had low compression in num 6 as the second ring was broke due to the cracked ringland

polish the crank and replace the bearings. The additional cost isn't that much when you consider the total rebuild cost. Its best to do it right, just in case he needs to put that 3.4L off a little longer.

Project89 09-29-2012 10:07 PM

Quote:

Originally Posted by ap72 (Post 1594966)
polish the crank and replace the bearings. The additional cost isn't that much when you consider the total rebuild cost. Its best to do it right, just in case he needs to put that 3.4L off a little longer.

problem is finding a place that will polish the crank in his area.ill tell him to look around some more.

the big thing is if the engine ran fine before it came apart why would u change the bearings and not just reuse them, each rod got number punchedas to what cyl it came out of so they wouldnt get mixxed up and the bearing would go back in the same exact spot

or is my reasoning wrong on that point

BOBCRMAN@aol.com 09-30-2012 05:09 AM

Normal wear pattern, as stated, polish and replace bearings. Do it correctly the first time. Cost is much less in the long run.

Steel 09-30-2012 05:20 AM

There are many shops that you can ship the crank to that will do a fine job. The added cost of shipping is well worth the longevity of the engine let along the piece of mind knowing that it's done right.....

cobalt327 09-30-2012 05:27 AM

My opinion
 
Quote:

Originally Posted by Project89 (Post 1594962)
this is my friends 3.1L v6 with a turbo about 120k on the engine and he managed to break the 2nd ringland on the number 6 pistons.

he just bought a house so he wants to get this back together as cheap as possible, as it would be a waste to spend the money on the 3.1 when he can build a 3.4L for the same money.which wont be till next year since he just bought a house.

so the plan is new ring set, 6 new hyper psitons and do a quick flexhone job to get the rings to seat.

my thoughts on the bearings are just to reuse the originals since they are worn in anyplace that needs clearance and they dont look bad.


what do u guys thing would u resuse them or would u slip new bearings in there even though the crank has some slight scoring from dirt passing threw.

the engine ran perfect, had great oil presure before it was torn down, it just had low compression in num 6 as the second ring was broke due to the cracked ringland

The right way and the cheap way don't always coincide. Rarely, actually. If this engine is not a keeper, reuse the bearings and crank as is. Unless the engine is coming all the way apart and thoroughly cleaned, the new bearings on a polished crank will look the same as it does now in a thousand miles anyway.

ap72 09-30-2012 08:28 AM

If you're hard pressed you can polish your crank yourself with some super fine sand paper (400, 600, then 1000). You need to be very careful and try to do it as evenly as possible. I've done it this way with no ill effects BUT others have tried it and had problems. When possible I send my crank out to be polished for $50.

cdminter59 09-30-2012 08:39 AM

Rod bearings/ main bearings
 
Why at these prices would you not want to replace the bearings. King Engine Bearings MB4080SI - King SI-Series Main Bearings - Overview - SummitRacing.com King Engine Bearings CR605SI - King SI-Series Rod Bearings - Overview - SummitRacing.com You have the motor apart clean it up good with a degreaser. You will have new pistons and rings, do it the right way and replace the bearings too.

Project89 09-30-2012 02:48 PM

Quote:

Originally Posted by cobalt327 (Post 1594992)
The right way and the cheap way don't always coincide. Rarely, actually. If this engine is not a keeper, reuse the bearings and crank as is. Unless the engine is coming all the way apart and thoroughly cleaned, the new bearings on a polished crank will look the same as it does now in a thousand miles anyway.

thats kinda my thoughts on the whole deal, i mean if he didnt break a piston.(mostly caused by the way over tight top ring gap) this engine would have ran another 100k

the engine is comming all the way apart so he can hone the cyls and clean the block but its not getting hot tanked or anything, he will be doing it in his garage.

this engine is more of an an experiment for him as he is very new to turbos and tunning the fuel injection system, thats the reason for doing it cheap as possible.

when he first started he wanted to pull the original engine and build a 3.4 with better parts but i talked him out of it cause i new he would hurt the engine eventually

without having to touch the crank or bearings this is the cost so far

speedpro pistion and moly ring set 102$'s
flex hone 30 bucks
+ whatever the machine shop wants install the new pistons on the rods
gasket set 50 bucks

so without the additional 200 bucks or so to have the crank done its damn cheap, and is perfect for hm incase he blows up up again, once he knows the thing isnt going to detonate or blow up again then he can step upto a good built 3.4L engine

he just stepped up up from a t04b turbo to a gt3582 so were the t04b made 350ish hp @ 16/17 psi. The gt3582 is going to make that at around 9/10 psi,and at 16/17 psi it should be making 425hp . so there is a good chance hes going to hurt this engine again anyways

cobalt327 09-30-2012 09:47 PM

Quote:

Originally Posted by Project89 (Post 1595165)
thats kinda my thoughts on the whole deal, i mean if he didnt break a piston.(mostly caused by the way over tight top ring gap) this engine would have ran another 100k

the engine is comming all the way apart so he can hone the cyls and clean the block but its not getting hot tanked or anything, he will be doing it in his garage.

this engine is more of an an experiment for him as he is very new to turbos and tunning the fuel injection system, thats the reason for doing it cheap as possible.

when he first started he wanted to pull the original engine and build a 3.4 with better parts but i talked him out of it cause i new he would hurt the engine eventually

without having to touch the crank or bearings this is the cost so far

speedpro pistion and moly ring set 102$'s
flex hone 30 bucks
+ whatever the machine shop wants install the new pistons on the rods
gasket set 50 bucks

so without the additional 200 bucks or so to have the crank done its damn cheap, and is perfect for hm incase he blows up up again, once he knows the thing isnt going to detonate or blow up again then he can step upto a good built 3.4L engine

he just stepped up up from a t04b turbo to a gt3582 so were the t04b made 350ish hp @ 16/17 psi. The gt3582 is going to make that at around 9/10 psi,and at 16/17 psi it should be making 425hp . so there is a good chance hes going to hurt this engine again anyways

If the engine is coming all the way apart, I'd tend to side w/the "polish the crank and replace bearings" crowd. Mic the journals carefully to be sure there's no factory undersized sized journals involved so you're not tripped up by that and you should be OK as long as you're giving it a good cleaning. The added cost should be in the area of $100. If you choose to go this route be sure the crank is polished in the direction of rotation.

If that's still too much, I have polished (and removed storage surface rust) from my own cranks using a piece of leather strap wrapped around the journal to hold a piece of 600 grit wet or dry paper wetted w/solvent (like WD-40). Pulling on the ends of the strap in a back and forth motion will take the worst high spots off the crank journals and costs basically nothing but your time. Bearings can be had for well under $50.

Project89 09-30-2012 11:31 PM

Quote:

Originally Posted by cobalt327 (Post 1595258)
If the engine is coming all the way apart, I'd tend to side w/the "polish the crank and replace bearings" crowd. Mic the journals carefully to be sure there's no factory undersized sized journals involved so you're not tripped up by that and you should be OK as long as you're giving it a good cleaning. The added cost should be in the area of $100. If you choose to go this route be sure the crank is polished in the direction of rotation.

If that's still too much, I have polished (and removed storage surface rust) from my own cranks using a piece of leather strap wrapped around the journal to hold a piece of 600 grit wet or dry paper wetted w/solvent (like WD-40). Pulling on the ends of the strap in a back and forth motion will take the worst high spots off the crank journals and costs basically nothing but your time. Bearings can be had for well under $50.

thanks he has the tools to mic the journals and bores and everything is well within spec.

if he does go the polishing / ne wbearing route i have told hime he needs to spend money and go with king engine bearings


my old shop trusted these bearings in everything form top alky engines to dialy drivers even down to our shops bobcat and forklift. i personally use king and nothing else

if he goes with the polish i told him to get them .002 undersized for some high rpm use

my motor which has been bulletproof is .002 under on rods, and i belive the same on mains , along with a modified oil pump and it lives happpily at 8,000+ rpms

Choctaw Bob 09-30-2012 11:59 PM

If the money really is that short, you can always scrape the journals with a penny. That will show you how rough the crank really is. If it passes the test, clean it thoroughly, reuse the crank and bearings with the understanding that it won't be bullet proof, but I've seen a lot worse run for a very long time.

Project89 10-01-2012 12:13 AM

Quote:

Originally Posted by Choctaw Bob (Post 1595283)
If the money really is that short, you can always scrape the journals with a penny. That will show you how rough the crank really is. If it passes the test, clean it thoroughly, reuse the crank and bearings with the understanding that it won't be bullet proof, but I've seen a lot worse run for a very long time.

already done, no copper bits got left on the journals

Choctaw Bob 10-01-2012 12:21 AM

Well then, you guys have to estimate the risk and either try it or bite the bullet and fix it right.


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