300 mile motor, ruined thrust bearings.

[baby6]

Title says it all. Started to develop a ticking noise after a couple hundred miles, oil pressure
Started to drop, ended up pulling the motor today and number 2 and 3 main bearings were completely wiped. Motor originally broke Crank between number 1 and 2 rod
Had the block completely gone over, didnt need a line hone, tanked it, new rings, cam, lifters etc.
Clearances were great (between .0015 and .002 across the board on mains) spun like butter.
What happened....? Broke the crank due to detonation over time.

 

[coach]

What convertor do you have?

 

[baby6]

3000 lockup 9" from ck performance.

 

[coach]

3000 lockup 9" from ck performance.

I've seen the 5 disc Vigilante cause similar issues. So much for that. Good luck finding your issue.

 

[bison]

Post pics of failures

 

[Nick Micale]

Title says it all. Started to develop a ticking noise after a couple hundred miles, oil pressure started to drop, ended up pulling the motor today and number 2 and 3 main bearings were completely fried. Thrust was down to copper on both sides overlaying the cap. Motor originally broke Crank between number 1 and 2 rod
Had the block completely gone over, didnt need a line hone, tanked it, new rings, cam, lifters etc.......

How in the hell did a block that had just broke a crank NOT need a line hone?

We would NEVER build any engine, even just a freshen with just new rings and bearings, and not do a line hone?

Only 2 ways a thrust is trashed, converter pushing on the crank or BAD machine work. If you used the same trans/converter, that shop owes you big time.

I had a similar thrust bearing situation a couple years ago and the shop said all the tolerances were perfect, but that machinist, if he was really a machinist, was either lying or stupid to protect his ass. When we checked the block crank bore, tolerance on the thrust was WAY too tight, and trashed the bearings in less than 100 miles.

Good luck on getting this taken care of properly, if you need help, let me know.

 

[The Radius Kid]

How in the hell did a block that had just broke a crank NOT need a line hone?

We would NEVER build any engine, even just a freshen with just new rings and bearings, and not do a line hone?

Only 2 ways a thrust is trashed, converter pushing on the crank or BAD machine work. If you used the same trans/converter, that shop owes you big time.

I had a similar thrust bearing situation a couple years ago and the shop said all the tolerances were perfect, but that machinist, if he was really a machinist, was either lying or stupid to protect his ass. When we checked the block crank bore, tolerance on the thrust was WAY too tight, and trashed the bearings in less than 100 miles.

Good luck on getting this taken care of properly, if you need help, let me know.

Easy big guy.
Stop making sense here.

 

[baby6]

Pics

 

[Paul Lohr]

If the block and main caps are reusable, it might be a good idea to have the alignment of the main bores checked. Not totally sure, but I think a machine shop can do this by taking a light cut with a line boring setup. Pretty sure I would have the block and main caps line bored before reassembling the motor.

 

[XXQUICK6XX]

I'd find another machine shop. Looks like it can be saved. I'd invest in a steel crank and caps while apart. But that is just me.

 

[bogies87]

Looks to me like improper machine work. While i agree with Nick on the causes of a thrust bearing failure, the thrust surfaces appear to be intact. Only 1/2 the bearing is trashed which indicates a improper line bore or bent crank.

 

[earlbrown]

Was that engine started with no oil pressure (then primed and restarted)? What do the rod bearings look like?

 

[750H.P.V6]

When I looked at these pics I came up with the same question that Earl just posed. It looks a lot like a motor I saw where they had changed the timing chain and never primed the motor prior to starting it. It ran dry for a while before the oil pump primed itself. By then the damage was done. The motor suffered a similar fate to yours within a couple of hundred miles.

Neal

 

[baby6]

We primed that motor for minutes, prior to installation.....rod bearings looked fine except for they had copper spots in them due to metal flowing through
The passages. Line hone or bent crank? Im not sure. It spun so nice...
My possible theory is I ran the motor a little too hard (some runs after break in), heated up the 5w30
To the point of no return and the 2 mains took the punishment.

 

[earlbrown]

If it tuned nice the crank couldn't have been that bent. Let's say the main clearance's were .002" (width of forearm hair). If the crank was bent more than .oo2 it wouldn't have spun freely.

I'm just amazed at how evenly worn the coppper colored bearings are. The reason I asked about the rod bearings was because I was curious if any of the bearing material made it's way to the rods. Were any of the rod bearings curled in enough to let them fall out of the rods and caps?

 

[baby6]

Nope. Rod bearings were all round. The only bearing that was egg shaped (see pic) was the other half to the thrust.

 

[haywire4130]

Where did you get the crank? Try this: borrow a dial indicator with a magnetic base (or buy a cheapie from harbor freight). Set the crank in the block on the bearings and check for runout on the snout (where the balancer goes). A few thousandths of runout will cause the crank to walk forward (just like being pushed by a bad converter) and will trash a thrust bearing quick!

 

[turbo nasty]

Were the plugs pulled on oil galleys and all cleaned out well prior to last rebuild?

 

[Grumpy]

Were the plugs pulled on oil galleys and all cleaned out well prior to last rebuild?

or was stuff magged ??? I think he just went threw some tranny stuff to.

 

[turbo nasty]

I agree seems as tho a few things contributed to its demise