how are ''big rig diesels'' so durable?
 

I was on the cummins web site and they have motors that have 10 to 15,000 mile service intervals one motor you put 1 million miles on it before any major overhauling.Iam pretty sure I read this right but you never know.How can they do this why can't they do this with autos? Will my barely broken in compared to these trucks 240d with 323,000 make the million mile club? I know its not fair to compare A 20 year old motor with A brand new state of the art one,so any body out there thinking of dropping A big ol cummings in there benz you would finally have all the power you need.:D :D btw what is the avarage amount of miles on A big rig?

Much of the wear in internal combustion engines comes from the start up... where the parts in the engine have not heated up and expanded to the size they will be in the work mode..
I expect the number of ( cold) starts per mile of usage of a passenger car to a truck ( where in many instances they don't even shut them down at night due to running the ac for the driver and or the freight ) is much much higher....
Then factor in huge filters, many times better record keeping and maintenance... and overdesigning of the work surfaces and bearings in the first place.... and they are going to average lasting longer...

Re: how are ''big rig diesels'' so durable?
 

A big part of this comes from the fact that USA-spawned, over-the-road truck engines are, generally speaking, long-stroke engines. They simply do not turn the high RPMs that a smaller, automobile-style engine will spin. They also carry huge amounts of lube oil. Both of these features go a long way towards extending the life of any engine.

Good question; how high is up?

For reference, the mid-1960's model, 220 Cummins Freightliner my Dad drove back in the 1970-'71 was already clocking 1,000,000+ miles.

I have kicked around the thought of dropping one of those Cummins engine/tranny out of a Dodge pickup into the W123. I have not found a used Cummins engine that was within my price range:(.

The answers thus far are valid ones, but to REALLY understand why this is, stop by your local Cummins shop and ask to see one that is torn apart.

Once you look at the parts I think it will clear up a lot.

This is no mistake, it is common for these engines to go a million miles between overhauls. Also they take about 12 GALLONS of oil at change time. The filter is HUGE.

If you ever want a real thrill, try to get a chance to stand in the dyno room with one of these big Cummins when they load it down at full throttle. It is an experience that is totally impossible to describe. The only other thing I've ever done that compares is throwing a live hand grenade. Both of them SHAKE the ground and shake it SERIOUSLY.

Have a great day,

Neither have I, which is why there isn't a 6BT Cummins in my pickup right now.

I don't think a 123's suspension could handle a 6BT...they weigh in at over 1000lbs; even if it were done on a 1/2 ton pickup, some front suspension modifications would be in order.

A 4BT 4 cylinder, OTOH...just as reliable and BOMBable :D but might fit in better for space as well as weight.

On the other other hand, I would think that an OM616/617 is about as reliable as a 6BT Cummins...I was under the impression that 500K and up was routine for a properly maintained 616/617...this was one of the deciding factors for me getting one. :)

Now thats funny! :)
By the time you design or swap in a front suspension that can handle the weight of a 6cyl cummins, make room for a tougher trans, drive line and then come up w/a steering system that would make it remotely user friendly on the street w/o serious understeer in corners, then swap out the puny MB rear axle/suspension to handle the cummins torque...you'll see the used cummins motor was the cheap part. You'd be bucks ahead and have a safer to drive rig if you just bought a Dodge truck w/cummins and have the frame/drive line sectioned/shortened and drop a 123 body on it.

Guys, I wish to heck I had taken a foto of the Cummins turbodiesel in a International Scout I saw last summer. The "thing" passed by as I was working on my 300TD, and I instantly stood up to see where the diesel was, but it looked so stock I couldn't figure what I was hearing. The driver parked nearby. When I approached him about the sound, he popped the hood and showed me. It was a big TDI Cummins, shoehorned in to say the least. He had a big intercooler in front of the radiator, too. He said the thing would burn rubber in third gear with little stock tires, and I believe it lacked a limited slip differential.
Yaahooey! I want one in a 300D! :p
Dieseldiehard
1971 220 (gas) 4-spd manual 104041
1979 300TD w/ ’85 turbo engine 289560
1983 300D 237490
1985 300TD 206150
1975 300D (looking for an engine)

I always beleived it's better to let the car idle ( higher ) when you run to the store on short term than to turn it off and back on again. I do lot's of higher idling in winter time.

I work for steel factory here in edmonton canada as a carrier operator ( big caterpillar ) ladle carrier it has 6 inline engine and that thing never shuts down except for oil service. I run it 10h/d 4 days a week on my shift never had a problem with the engine since they bought the thing 20 years-ago

As nice as the Cummins probably are, they are so darn loud! Who wants to listen to that mechanical noise all day long?

Now, isn't MB planning to drop the Cummins engine from the Dodge lineup in the future with their own CDI engines? I have heard rumors about the CDI's being unreliable, but none about the Cummins being anything BUT reliable.

Still, I do not care for headaches(not in pricing, i mean real sound induced headaches). I haven't heard the new Cummins before, it is supposed to be quieter.

BTW, it is not uncommon in South America to see old W123 taxi's with more than a million miles on them in good working order. No rebuilds or anything. As was said before, the most wear in an engine occurs when it is cold.

Big diesel engines are seriously overbuilt by automotive standards. They have, as noted, huge oil reserviors -- dry sump systems, I think -- and usually have a bypass filter system better than the one on the Benz. It's easy to engineer something to last that long, but no one is going to buy it for automotive use, it's serious overkill. Most cars die from body rot, not engine damage, and very few people actually run a car like an over-the-road truck!

Peter

Would one of those devices that circulate the motor oil before starting extend the mileage enough to make it worth the cost of installation?

At one time you could get an IH Scout with a Nissan 6 cylinder diesel engine, I had a 63 with their 4 cly. gas it was a good engine but had lots of drive line problems..........
William Rogers........

I drive busses for my school as a student job.. I got a free CDL out of it and get to pilot big diesels every day.. it is wonderful for me. Anyways, most of our busses are equipped with 5.9 Cummins, in both 12 and 24 valve versions. We also have a couple of bussed with 8.2 Detroits as well as a Cat (can't remember the model, but it is 360 HP), and 2 Sprinters.. a Dodge and a Freightliner.
Being ran 18 hours a day is hard on the engines, and actually, I have yet to see one die outright. We had one that had a tear in the inlet hose after the air cleaner, and months of driving through construction destroyed its rings until it let loose with one of them with me one night on the road, and it burned half of its oil capacity getting back to campus. Other than that and one of our 8.2s throwing a rod, we have never had a single one fail, and our mileage ranges from 12,000 on the Cat (It's in a 2003 Blue Bird Excel 102) to over 1,000,000 on a 1978 Blue Bird All American.
~D.J.~

I ran a little tug for the paper mill here. It had a 343 Cat. I changed lub oil and filters every 125 hours, 8 gallons of Delo 400. The engine was rated at about 400 HP if I remember right. Now that seems like allot of lub oil changed at short intervals compared to automotive diesels. Also It was not turned up over 1800 RPMs.