i am a young kid just trying to learn the basics of a diesel i have acouple of questions.
why is it that you can recive so much more gain on power by doing a few simple mods on a diesel and on a gaser it takes alot more to gain the same amount of power.

why do diesels last so much longer in the long run with much less problems

and why at stock power do they produce so much more torque than a gaser

 

I am an olde pharte and just learning myself ...

One reason diesels last a long time is because they run at lower rpm's then gassers ... Less friction ...

Also diesel fuel ittself is a thicker fuel ... Hence it tends to help in the lubrication of the engine a lot better than the thinner gasoline ...

Also, and the techies here can explain why, diesel fuel packs more power in it when compared to gasoline gallon for gallon ...

 

Turbocharging!!! Most people that dont know engines think fuel makes power, the truth is its easy to add fuel, its harder to get more air, turbocharging does wonders in this department making an engine act bigger than it is. Also gasoline engines suffer from detonation under high load (this is also known as knock or pinging) and is uncontrolled spontaineous combustion of the fuel, in short this isnt good and destroys gas engines. A diesel engine operates by by knocking at a controlled injection event. In short gasoline is limited by the octane of the fuel, diesel isnt.

Low RPM = longevity

Turbocharging!!!

 

It also stands to reason that do to the nature of how diesels run that they are built a lot more stoutly than their gasoline counterparts. They are just plain beefer! Hence, it would stand to reason that beefier parts should last longer.

 

Turbocharging doesn't necessarily mean more torque than a gasoline motor. Diesels have a significantly longer stroke than a gas motor, which creates more torque. Diesels last longer than gasoline motors usually, because they are built to withstand high combustion pressures, and as such usually have cast iron bottoms and cast iron heads. The Duramax has aluminum heads, but a lot of large commercial diesels have cast iron heads. They also turn fewer rpms. Gas motors are more picky when it comes to adding power as you have to pay close attention to spark timing, you can't just add a crap load of fuel. Diesels really just need air and fuel to run, well and electricity with newer computer controlled trucks.

 

Compression ignition engines (diesels) by nature are constructed stouter than their gas counterparts, and along with the higher compression ratio often comes extra piston rings. Also, most diesels will never see the far side of 3,000 RPM, thus they aren't subject to quite the same wear as a gasoline engine. That in a nutshell explains why they have the potential to last longer. I say potential, because without proper maintenance it's all for naught.
Secondly, diesel fuel itself is a long chain hydrocarbon resembling oil more so than gasoline, thus it offers more BTU's and power per molecular unit burned. That's why fuel oil is used for home heating.
Diesels respond well to modifications for one primary reason, they're volumetrically efficient. Think about it: no carburetor, no spacer plate, no intake manifold to be modified. Same goes for the camshaft, unlike their benzine burning cousins.
Having said that, mods come at the cost of a shorter lifespan. Why is that so? Put simply, more fuel means more thermal stress (heat), and in an engine that doesn't have a large enough cooling system that means a shorter life. That's one reason why turbo diesels are after cooled, the other is that cooler air is more dense than hot air, thus more power via more oxygen. That's why gauges are popular mods. You can't keep her alive if you don't know whats going on inside.

 

all of these guys have done a good job answering your questions. if you wanna take things a bit further, and learn more, the best way is reading these forums. Also, experience. You really can't beat experience. I worked for a construction company for about a year during and after HS. I worked with an ASE master tech who previously worked at a very reputable shop in the area. I learned more from him than I could ever imagine. More than I learned in 3 years of HS auto-tech classes.



-brian

 

One thing you can do for yourself. Is do a web search "diesel engines" you'll get lots of good info. I use MetaCrawler Web Search Home Page for my search engine.