Why do Diesels last longer than IC's?

[Buck]

Why do Diesels last longer than IC\'s?

What is the basic reason Diesel's last longer than Internal Combustion engines?

Thanks,
Buck

 

[Buck]

Re: Why do Diesels last longer than IC\'s?

I should have said "Why do Diesel's las longer than gasoline based engines". /w3tcompact/icons/blush.gif I guess they are both internal combustion.

 

[jdkid]

Re: Why do Diesels last longer than IC\'s?

Hi ya
i'd say speed RPM have the most to do with that if ya think about it the blocks are much the same only the heads/inlet for fuel is diffrent .i think someone worked out a set of rings (in good running order clean air oil changes etc etc)would go 300,000 KM (1 mile=1.6 Km)before being worn out so working on that a motor doing 4-5000 RPM vs 1800 what should in thoury last longer.
catch ya
JD Kid

 

[MChalkley]

Re: Why do Diesels last longer than IC\'s?

A major factor is that diesels burn oil, while gasoline engines burn a solvent.

RPMs are a factor, too, as was mentioned.

Diesels are also built a lot stronger because they have to be to withstand the combustion and heat stresses. Remember two glaring examples of diesels that didn't last as long as typical gasoline engines? Both were products of GM engineering, one was a truck engine (they called it the Toro-flow - everybody who ever owned one called it a Trouble Flow), the other one was used in a lot of cars during the 80's "energy crisis". Neither was worth a plug nickel because they were converted gasoline engines and they weren't designed to handle the additional stresses.

 

[Bird]

Re: Why do Diesels last longer than IC\'s?

Mark, I'd be the first to admit that GM erred with that gasoline converted to diesel engine, but my brother bought a used one and only put another 30k or so on it before trading again, but no trouble with it. And my wife's brother (up in your area - lives out around Manasas and works in DC) bought a new one that they put over 100k on with no problems. It seems that the buyers who knew anything about diesels and used the proper oil and filters and changed them when they were suppposed to actually had very little trouble with them. Now of course I wouldn't expect them to hold up for 300k like a "real" diesel engine.

 

[bgott]

Re: Why do Diesels last longer than IC\'s?

Another problem with them was finding people qualified to work on them. Auto shops didn't want to touch them because they were a diesel. Truck shops wouldn't touch them because they were in a car. Nobody wanted to pick up the shop manual and read up on them.

 

[jdkid]

Re: Why do Diesels last longer than IC\'s?

HI YA
yep true they are built stronger ,i don't know if the oil/solvent realy comes into it that much as both should burn clean the only thing is a diesel add the fuel at the top of the stroke where a carbed motor fills the pot full lenght of stroke ya could say the gas/air mix could wash the walls making the rings run on a poor lubed suface i don't know if it would make a big efect but it might .
catch ya
JD Kid

 

[MChalkley]

Re: Why do Diesels last longer than IC\'s?

Bird - They seemed to have highly variable life-spans, too. I know a guy right now who has one with a little over 200k on it and has never had any trouble. When I lived in FL in the early 80's, my boss bought a Cadillac with the diesel in it, and went through 1 rebuild and 2 new engines (not counting the one in the car when he bought it), all before the car had 50k on it - and I know for a fact that the car got meticulous maintenance after the first engine was rebuilt, because the dealer insisted on doing it. When they put the last diesel in, they begged him to let them covert it to a gas engine, but he refused. In the end, he got a lawyer and they gave him his money back - all of it - and he bought a Mercedes. So different people got very different results, but overall a very small percentage of them lasted as long as a typical 350 gas engine did.

My father had a Trouble-Flow diesel when he had a trucking company while I was a kid. He got about 350k out of it, but it took several heads and more than a dozen head gaskets to do it (he says it was 17, I don't remember, but I know "more than a dozen" is safe). I think that truck is essentially where my prejudice against GM stems from - I can remember changing head gaskets in that thing in the middle of the night, in freezing cold, in blazing heat, you name it. I'm still holding a grudge. /w3tcompact/icons/smile.gif

 

[RobS]

Re: Why do Diesels last longer than IC\'s?

I'd chalk it up to basic design. Neither is inherently more durable. Most diesels are in applications where the customer expects longevity so the manufacturers design in the necessary robustness. A gasoline (spark ignition or SI) engine COULD be made to last longer but most are in cars and light trucks with a 100k mile design bogie. Look at the old SI farm tractor engines. They seemingly last forever.

On the other hand, a diesel (compression ignition or CI) engine can be designed for lower life as well. Take the infamous GM V8s already mentioned in this thread.

If diesels become more mainstream in this country for personal use vehicles, you can be sure they will be "cost reduced" to the point where they will only last around 100k miles like their gasoline counterparts /w3tcompact/icons/smile.gif

 

[HalseyGreen]

Re: Why do Diesels last longer than IC\'s?

Back in then late 70's and early 80's I spent a considerable time towing an Airstream around this country, came across quite a few very knowledgeable people on diesels. They were putting all kinds of diesels in their Suburbans and Pickups, Detroit 4-53's, duetz air cooled, even a couple of small Cats . What was shared with me on numerous occasions was that the GM 350 diesel was a great engine, if its "power stroke" was balanced, a compression test would disclose a variance between cylinders. At an Airstream Rally in New Jersey in 1985, they had a GM Diesel engineer as a guess presenter, he confirmed to the group the above problem with the 350 diesels. It appeared that most were not balanced, thus they beat themselves apart.