Engine/Transmission (1998.5 - 2002) Burned up my engine today

[RustyJC]

Personally, I'd rather run one cylinder 0. 020" over than throw in a dry sleeve (which impedes heat transfer) and run it standard.



JM2CW



Rusty

 

[dresslered]

I agree to stay away from sleeving, but I think that I would go all even (20 over) since we are dealing with such high compressions.

 

[John Berger]

Reading this thread has been very informative and also makes me very happy that I stuck with my decision on 275's. I rarely see EGT's over 1050, even pulling that long 6 percenter on the newly completed I-26 in North Carolina. In fact that's where I got the 1050 reading, last August. With the stock exhaust system, I probably would have got it up to 1250 or so. The 4 inch exhaust was one of the better upgrades that I did. I almost purchased DD2's last year, but now I know I'm sticking with what I got. Good luck with the rebuild Cliff. Sorry you have to do it in the first place. That #6 piston has seen better days, hasn't it?

 

[Cliffman]

After pulling the engine apart last night we had a chance to look at the rod and main bearings. After 147k miles the down stroke side of the rod bearings is worn down to the brass and the up stroke side looks almost new. Main bearings also look almost new. Been running Amsoil for 130k Miles. Not sure what to make of this. I know the down stroke is where the most wear is applied but having it down to the brass worries me.

 

[RustyJC]

Originally posted by dresslered

I agree to stay away from sleeving, but I think that I would go all even (20 over) since we are dealing with such high compressions.

David,



I would, too, if I'm spending your money!



Rusty

 

[Gary - K7GLD]

"After 147k miles the down stroke side of the rod bearings is worn down to the brass and the up stroke side looks almost new. Main bearings also look almost new. Been running Amsoil for 130k Miles. Not sure what to make of this. "



Yeah, that IS interesting at those relatively low miles, isn't it...



Wonder what they'd look like at the 400,000 miles the engine is supposed to be good for...

 

[jrandol]

Heck, just bore and stroke it out!! I got the feeling the big power guys are doing more of this than they care to tell us.

 

[RustyJC]

Originally posted by Cliffman

After pulling the engine apart last night we had a chance to look at the rod and main bearings. After 147k miles the down stroke side of the rod bearings is worn down to the brass and the up stroke side looks almost new. Main bearings also look almost new. Been running Amsoil for 130k Miles. Not sure what to make of this. I know the down stroke is where the most wear is applied but having it down to the brass worries me.

Your "upstroke side" and "downstroke side" description is confusing. Assuming you're talking about wear in the area from 10:00 to 2:00 or thereabouts, I offer the following:



On a micro-babbitted trimetal bearing, the babbitt overlay is only 0. 0005" to 0. 001" thick. It's there primarily to provide conformability and embeddability during break-in. The reason that the bronze intermediate layer is present is that it is the primary bearing material in the trimetal bearing. The steel back (the third layer of a trimetal bearing) is there to provide strength and dimensional stability.



If there's no scoring, peeling or other abnormal damage (i. e. , if the exposed bronze area looks smooth and normal), and if the crank journal shows no damage, I wouldn't consider what you're seeing to be anything alarming. The "plastic" soft babbitt has been extruded from the high load area of the bearing by the high peak firing pressures, and the stronger bronze layer is carrying the load, as it's designed to do and can do for many hundreds of thousands of miles.



Having said the above, I would be careful to avoid low RPM/high "throttle" opening operation (i. e. , "lugging") as much as possible as this is where loads in that area of the rod bearings are the highest.



Rusty

 

[John_P]

Cliffman:



Sorry to hear about your truck!



I wanted to let you know that Scheid Diesel is rebuilding my

96' 12 valve engine right now. That truck has a little over

230,000 hard miles on it!! You can look at my "signature"

to see what "mods" I have. Like you, I tow heavy in the

mountains of the east coast, (10,000 lbs. +). I also have

over fifty (50) drag race "launches" on it and I can't count

the number of times I have looked up to see the pyrometer

over 1300 degrees!!! FYI, my truck didn't quit, but

I was beginning to get a good amount of "blow-by" and was

starting to use some oil too.



Anyway, when they tore my engine down, I was pleasantly

surprised at how good the inside of the engine looked

considering how hard I ran it! You could still see that

distinctive "crosshatching" on cylinders 1,2,3 and 4.

However, cylinder #5 and #6 looked pretty well worn

to me, but Scheid and the machine shop said they were

not worn enough to have to bore to . 20 over. Honing should

take care of it! The pistons in holes #5 and #6 were

cracked at the very top, right on the edge of the little

"hole"; #5 being worse than #6. The wear on my bearings

were opposite of yours. The #5 upper rod bearing had the

worst wear with the wear almost being through to the

copper. The bottom rod bearing was also worn, but not

as bad as the top. All of the main bearings seemed to have

"equal" wear with #6 looking a little worse.



Good luck with your rebuild!! Just wanted to share what

I saw in my 12 valve with you!



---------

John_P

 

[Cliffman]

Great post Rusty! Thanks

 

[ThrottleJockey]

Cliffman, PLEASE!!! Listen to this BEFORE you make your final call!!



That rod bearing condition you described is from ADVANCED TIMING!!



TRUST ME!!! I would not steer you wrong, you are my TDR brother! I have over 600,000 diesel miles under my belt, I have an ETH and a modified Kenworth Cummins BC 3. They are now both set up the same way! They sound and feel almost exactly alike! The KW's parts are simply mathematically bigger.



If it wasn't for the Amsoil, you wouldn't be doing a rebuild. You'd be shopping for a Ford.

Bore ALL the cylinders and use a new set of overbore pistons. If you use Cummins pistons, fine but at LEAST put a 20 over headgasket on it TO LOWER your compression. You will still have enough meat in the block for 2 more rebuilds AND 1 rebuild with sleeves!



The most effecient way to cool off a diesel is to put it in a hull and throw hundreds of gallons of seawater at it, the second best way is BOOST! Your number six cylinder melted because a whole bunch of things came together and created a runaway heat situation in your last cylinder, ask yourself why the rest didn't grow so much to score the wall.



Put the turbo boost to your new engine and don't tow with ANY products that advance timing.



Brian

 

[RustyJC]

You might want to read the following trimetal bearing publication from Clevite. Note the reference on page 2 to normal wear of the overlay layer and exposure of the copper-lead (aka bronze) intermediate layer.



And, yes, advancing timing will lead to higher peak firing pressures which will lead to higher rod bearing wear in the 10:00 to 2:00 areas. Exposure of the copper-lead intermediate layer is not, however, in and of itself necessarily a sign of impending doom. Rather, it will eventually happen over the normal life of a trimetal bearing as the soft overlay layer wears away.



Rusty

 

[Gary - K7GLD]

Wonder if an exhaust brake was installed - they can also affect the bearing wear patterns as compression braking is used...



As to any inferences that Amsoil "saved the day"... Well... .

 

[Cliffman]

Gary - KJ6Q



Yes, I have, and I use my e-break quite a bit. My last set of front pads lasted me 60k at least.





ThrottleJockey



Please be more specific as to why you would have me replace all the pistons.

 

[Cliffman]

Originally posted by RustyJC

Your "upstroke side" and "downstroke side" description is confusing. Assuming you're talking about wear in the area from 10:00 to 2:00 or thereabouts, I offer the following:

Well let me clear that up Rusty, what I mean by the "upstroke side" and the "down stroke" side is that I'm trying to reference which rod bearing is worn. The down stroke would the top bearing where it connects to the crank. Sorry for the confusion.

 

[RustyJC]

OK, sounds like we're both talking about the top shell. Just wanted to be sure.



Rusty

 

[ThrottleJockey]

Cliffman



Balance. Heck, Cummins wants you to put the flywheel and vibration damper back to the original orientation. Balance is a huge deal.









Gary,



You ain't never gonna find a better lubrication combo than Amsoil synthetic and 20% Lucas Oil Stabilizer! Nothing else even comes close!



I wish I hadn't recycled all my rods and mains and stock pistons, I would'a sent you some. ALL except number six mains were in perfect condition and that was AFTER ALL the oil was pushed out of the engine and pressurized COOLANT was shoved into the oil passages.

I thought I was gonna need a reman longblock or at least a new crank!



Nope



Brian



P. S. Got the same combo in my wife's 94 Grand Cherokee 4. 0. 100,000 miles and 10 years old, that engine is in perfect running order. The dealership mechanics cant figure out why this thing ain't dead!

 

[Cliffman]

Injectors

Okay men, here's another little tid-bit for all you diesel junkies to chew on. We sent the injectors back DD to have them checked out just to rule out the possibility of #6 injector over fueling and causing the melt down. A few days later I received all new injectors in the mail. No questions asked. I called and asked what was wrong with my original set and they said that ALL THE INJECTORS WERE BAD . Said that none of them would "pop off". Keep in mind that the truck was running even after the melt down. Hell, we even started it up and drove it up onto the car hauler to get it to my shop. All I can say is those are some "bad ass" injectors.

 

[Diesel Freak]

wow... so they all were dribbling?

 

[dresslered]

Sounds like you discovered the problem at least. I find it amazing that the truck didn't perform poorly, however?