Catastrophic engine failure

[mbryner]

Hello all,

As of yesterday, my JKson 6/1 is toast.   I let it run all night to charge batteries at our land/new house on Monday night.   Yesterday, the contractors said it wasn't running when they got there.  I was at work, but my wife was out there and she said she couldn't turn the crank and what little it moved sounded like terrible grinding.  After work, I raced out there and started taking things apart.   There was a little bit of thick "chocolate milk" goo around the head.   The reserve antifreeze tank is empty and looks like it boiled over because everything around it is wet.   The valves and head appear OK.   There is a little bit of "chocolate milk" and a some pieces of solid gunk in the coolant system.   The thermostat looks OK.  The piston is free in the cylinder, and the cylinder walls are not marred.   In the crankcase is where the really bad stuff is.   When I first opened it, there was a terrible burnt smell.   Small pieces of metal are scattered all over the crankcase (tiny pieces <1 mm in size).   The big end of the connecting rod is dry and burnt-looking.   One of the shims in the big end is hanging out.   The oil is still black (not chocolate-y) and the dipper is still contacting oil.   The sump oil is a little low but it could be worse.   Gears, tappets, etc. are grossly OK (didn't do detailed exam there yet).   It would appear that the big end bearing shells are destroyed and there's now hard metal against the crank journal.   

After looking at the Listeroid until about 8:30 pm and rigging up a backup pull-start generator for emergency power, I had to drive half the night to Portland, OR where I have meetings this morning.   After I get back home, I'll report more and post some pics.   Gotta get to that meeting...

     

Marcus

[JohnF]

Marcus;

It actually doesn't sound THAT bad.  Likely the big end bearings failed, the small pieces of metal you are seeing are probably babbit material.  If the crank is not badly scored it is recoverable.  Slight scoring on the crank can be polished out using emery cloth.  Check the crank for true, install new big end bearings and she should fire up.  These little buggers are tough as nails, I've seized pistons (more than once I'm ashamed to say) and when the engine cooled down it re-started with no problem.  You might want to check the piston rings as well - one could be cracked.  No water in the sump means the water rings are OK, so no need to removed the cylinder sleeve.

Do change the oil though before attempting a re-fire.

[mbryner]

Thanks for the reassurances.  About 350 hrs, regular red diesel.  Not running WMO yet.  (Texting from in seminar.....).  I have some extra shells but where do I get new ones?  The extra ones I have are a little marred.

I have an idea of what happened:  a few days ago my bridge rectifier died. When testing it I accidentally "locked" the ST head electrically while the engine was running.  It was only for a moment but the shock load/stop could have put severe strain on the shells and damaged them?

[mbryner]

How do I check crank for true?  Do I need to take out crank and micro-clean the TRB's?  I was going to wash out the crankcase with soap/water, regrease everything, etc.  How much scoring on the crank is too much?  I'll take pictures...

[Crofter]

You will have a better idea once you pull the cap off the rod. You will want to assess whether the shells turned in the rod. In checking for true use a chalk and block on the outer ends of crankshaft to give a rough check for bend in the middle. Journal should be not much more than half a thou out of round or taper. In cleaning up the surface, high spots of metal are more of an enemy to babbit than voids or slight furrows. It is much better if you can take the crank out if it needs much cleaning up as you can use a hard backing for the emery cloth so you can selectively remove only high spots. You can also fab a solid bracelet of wood or metal to hold the abrasive that will also do more to restore any out of roundness. Hope things look promising when you get the rod end apart.

[veggie]

You may have got lucky (best of a bad situation) and the big end bearing became the sacrificial piece.
A good inspection and clean-up is in order. Then you can assess the situation to see if the damage spread much further beyond the con rod shells. When you forward the pictures, we can get a better idea of the polishing required.
Good luck going forward,

veggie

[Tom Reed]

I've got a few spare sets of new spare bearing shells and I'm right off of 101 in Hopland on your trip back from OR. All I ask is that you replace them some time in the near future. I'd pull the head, cylinder and rod and give the fly wheels a spin and see how she sounds. Then put a dial indicator on the ends of crank shaft and see how much run out there is. Hopefully you bearing journal is ok and you can clean it up and get back into service. Did you plasitgauge the rod bearing before placing it into service? If so how did it measure?

[Chris]

Hope your big end journal is not too badly damaged. They can be cleaned up as mentioned above.
Remember these ain't no 5,000 rmp screamer. They will work quite well with a little slop for a long time. I think Central Maine may still have some shells at a very reasonable price. So you got to replace them once a year due to damaged journal. No big deal.
The shells can be changed with piston connecting rod in place. Just prop up the piston with a piece of wood, cut to fit. remove the bottom bearing ?? thing?? and tap out the top shell from the connecting rod. Check the journal and clean up (very carrfully) with flat file emory cloth etc

Clean her up. get the pieces out and I think you will be fine.

All the best
Chris

[mobile_bob]

were you using a hollow dipper and plain upper shell?

if not i would suggest upgrading to their use, and away from the original lister top oiling method.

i really don't believe the new manufacture shells have thick enough babbit lining to work well with the top oiling method
of the original lister design.

that and the fact that any crap that dislodges itself from the piston crown seems to find its way into one of the two hole and into the brg.

if it were me, i would also just take the time to tear it down completely, steam/pressure wash all the swarf from the crankcase, send out the crank for checking, staightening if needed, regrind or polish depending on what the damage is, and then reassemble to correct tolerances.

may as well do it right or you will likely get the opportunity to revisit the issue sooner than later.

unless you are luckier than i am

bob g

[Geno]

I'll second Bob's recommendation on the hollow dipper and solid upper shells as well as the rest if a careful inspection warrants it.

The hollow dipper and solid upper shells has made a big difference on my 6/1. I still ain't got the balls to run it all night, even if I'm 50 feet away in bed.

Thanks, Geno

[mbryner]

Thank you very much for all your insights.

The crankshaft looks pretty bad.   It's quite bent.  The ends of the crankshaft are bouncing up and down by about 1/4" when I spin it with the piston removed.   It took forever to get the connecting rod off the crank.   The bolts holding the lower end together were almost fused to the connecting rod and had to be pounded out.   One of the nuts was fused to the bolt and the bolt just sheared off.  (See pic.)    The crankshaft is heavily scarred.   I had a hard time getting the bearing shells out of their seats.  Some of the gouges on the lower shell were made by me bashing and prying the lower part of the connecting rod off.   Notice how burnt the lower end looks.

My father-in-law (who is a hobbyist auto restorer and pilot) told me tonight that in airplanes, if the engine stops abruptly because of propeller damage, they are required to do a complete engine rebuild because a quick stop can bend the crankshaft.   Then the slight bend causes a chain reaction: the bearings to overheat and then self-destruct.  Could I have bent the crankshaft slightly with the generator abrupt stop?  Yes, maybe just some crud fell down from the piston crown, but isn't that unlikely after 350 hours?   I just want to avoid this again.  If the crankshaft can't be fixed by a machine shop, where do a get a new one?   Or, if it's this bad do I take it to a machine shop.  And shouldn't I get another connecting rod?  Course I need new bolts on the lower end, too.   Central Maine Diesel doesn't seem to have any of these parts.   I'm trying to avoid taking the piston out of the cylinder since the cylinder is not scored and rings are a PITA to replace.   To get the wrist pin out I'll have to at least slide the piston out past the lower ring, though.

No, I'm not running the hollow dipper mod.   I was just using the shells that came with the 'roid.

Here are the pictures.  Click to enlarge.  (Unfortunately they open a new window.  I haven't figured out the in-line enlargement trick yet.)




Connecting rod with shell removed.


Sheared bolt, also.


Should have taken a pic of the backside, too, showing how the shell tried to spin but mangled the hole where the dipper was holding it back.








The dents are from me having to use a chisel to get it off.

Thanks,

Marcus

P.S.  Yes Jens.  And where do you get the hollow dipper?

P.S.2 :  Tom, thank you very much for your offer, but I live in Grants Pass -- you are quite a bit south of us.

[Apogee]

Hi Marcus,

Bite the bullet and take the whole thing apart.  If you don't, you'll likely be forced to later.

You will want to have the rod checked to ensure it's not bent.  You can't do that with it together.  Also, since it got that hot, I'd be taking it to a machine shop to have the big end checked to ensure it's still round while they're checking straightness.

I'd be leaning towards replacing the crank.  They *might* be able to straighten it, but you will have labor charges and you won't know with 100% certainty that there's not a stress fracture someplace from either the initial hit or the straightening process.

You can order parts from:

http://www.diesel-electric.us/

or

http://www.stationaryengineparts.com/home.php (in the UK)

or you might consider trying direct from India:

Devang Rathod
Devprecisionengineers@yahoo.com

Good luck,

Steve

[mbryner]

Thanks Steve.    Look at the previous post.  The crank is quite bent.  I sent e-mails to diesel-electric.us and Central Maine Diesel already asking about crankshafts and con-rod's.

[JohnF]

Marcus;

I think I have everything you will need, please PM me when you get a chance.

[mobile_bob]

if you are concerned about a hollow dipper breaking off, then use one with the std oem shells with the upper holes
open.

the hollow dipper will force many times more oil into the brg than will make its way down into the holes anyway, and if it did break off
the original design would kick in and oil would come through from the top, either way you are covered.

i agree with others here, a complete teardown is in order, if you don't replace the liner at least have it honed and replace the rings.

and make very sure the under belly of the piston is clean, no crap hiding up in there somewhere, last thing one needs is something else coming out from under there.

if JohnF has all your parts, you sittin pretty in my opinion, much better to  buy them from a north american supplier than do the import thing  yourself and have to wait forever to get your stuff. then have it come in missing an important part or wrong part that is needed.

from what i can see in the pictures it does look like it ran low on oil? is this the case?

when you get done rebuilding the old girl you might consider a remote oil tank with balance tube to extend the capacity of the crankcase capacity, that would  buy you some piece of mind for longer unattended runs.

bob g