Please explain this difference between diesel and gasoline engines

[pmsmechanic]

spark plugs, timed distributor, upper cams, carburetor or throttle-body, engine sensors for air mixture, PCV system, etc.

https://www.caranddriver.com/research/a31515330/diesel-vs-gasoline

Diesel engines also have fewer components than gas engines, which means your car has fewer potential parts that could malfunction.

I don't see anything about "early engines" in bmaverick's original statement.

 

[DieselBound]

I could care less if you call BS. I'm into vintage diesels only. The modern diesels are crap.

My diesel injection pump is super small, compact and easy to work on. Then after the mid-80 came the crappy Tier-1 emission junk. Yeah, those pumps are over complicated, lots of parts and involve timing. Nope, not wanting those problems.

I've got a plethora of diesels, all are, according to your timeline, modern "crap." Good on you for being into "vintage diesels only," but bashing anything that you aren't "into" just solicits a counter response.

I've NEVER had to touch ANY of the injection pumps (other than a slight adjustment known as "the hammer mod" to my ALH engines). Three generations of pumps.

I live out in the country and a generator for emergency use is essential. I don't take gambles on equipment here. What's the power plant used in my generator? Of course it's a diesel! It's a 1994 Kubota. According to you this puts it in the "crap" column. I'll wager any amount of money that I can walk out at any time and that generator fires right up (assuming I keep the battery maintained). If I'm not at home then I expect it to do the same for my wife.

I have a 94 Dodge 12v Cummins. Again, according to your classification window it's "crap."

Other than replacing a temperature sensor in the generator I've not touched anything on its engine or the engine in the truck. But you claim that everything past 1990 is "crap."

My 2006 Kubota tractor is "modern" according to your book. I bought it used (abused with 750 hrs) and now have about 1,300 hrs on it. I've not touched a single thing on the engine (only prescribed maintenance, the most "complicated" being valve adjustment), not even replaced a glow plug!

I was quite hesitant to buy my 2016 Kioti with the common rail and DPF setup (no DEF, thankfully). I decided to buy it because I didn't want another piece of older equipment to worry about: buying used stuff one ALWAYS encounters issues; my generator required work on the electrical output side, nothing that I was familiar with but being out in the country I've come to learn about everything I have. I had a ton of work to do when I got this tractor and it performed as well as, if not better, than I'd hoped. It now has 1,100 hrs and I haven't had a lick of engine issues, zero, nada. The risk paid off. Will it last until the end of time? No. Will it last to the end of MY time? Most likely.

I've had MANY MKIV VW TDIs (ALH engines), computer controlled injection pumps, and have had ZERO issues with any of the engines or computers (and I've racked up hundreds of thousands of miles with these). Everyone was predicting the end of the world when the computers were introduced: 22 years and closing in on 250k miles on our last and current TDI and it's going strong (even with performance modifications). OK, I forgot that I had to replace a couple of MAFs (some tuners can tune such that MAFs are not required) but they're cheap and take maybe 10 minutes to replace. There's also injectors but ALL diesels will require injector work/refreshing at some point. This is my personal experience, others have had bettor or worse outcomes and this can be said about pretty much anything.

I've now got two "modern" Mercedes diesel-powered cars, circa 2005. They're what allowed me to learn about common rail diesels: I'm an old dog that learned new tricks. These have the venerable CP3 high pressure fuel pumps which can last nearly as long as older, lower pressure mechanical ones. The bigger concern with these vehicles isn't the engines (om648, an engine I'll put up against most any other- it's a 6 cyl in-line which is of the same family of the 5 cyl om647s found in older, workhorse Sprinter vans), it's the rest of the car (CAN bus and all the electronic gadgets). I can find many examples of these cars/engines pushing over 500k miles: one guy found that after 400k miles the stretch on the timing chain (and gear wear) was still within spec! (<- modern diesel "overhead cam" stuff; no pushrods to bend!)

The VW TDIs were notorious for EGR and intake clogging. Much of this, however, was the result of mis-using such a tool. Short trips are not good on newer diesels: I'd note that in older diesels there was the "wet-stacking" concern which is kind of along the same lines. My om648s also only had EGRs but while they could add to coke'd up intakes it was a LOT less so than with the ALHs: and mostly the stupid intake swirlflaps (om648). Coking is happening with direct injection gasoline engines as well and is also likely due more to short-tripping but as I don't wade in gasoline territory (except a trimmer and riding lawn mower) I don't have my own experience with this. I CAN say, however, that with my VWs that after I cleaned out the results of "mis-use" and used these "tools" as they were intended that I have had ZERO issues: EGR held very clean after 100k miles on one car that I checked closely on- if OK at 100k miles then for all practical purposes I'd never have to touch the EGR/intake again.

As most of my experience has been with diesels in on-road vehicles I feel that they can speak to the reliability of a "modern" diesel. My last, and current, TDI is 22 years old and closing in on 250k miles. It still returns roughly 50mpg tanks. And it's got a LOT more power than any similary-sized "vintage" diesel: I've tweaked the power on it. If this isn't long enough or representative of enough serivce life then I don't know what one could be asking for. BUT this isn't the end of the story with this car and won't be for a LONG time.

The tools I've selected have been and continue to work really well for me. I'm not aiming to get into the Guiness Book of Records.

It's all about risk assessment! MY rationale for choosing diesel? 1) I can store it in bulk w/o the fear of a big explosion AND it can store for far longer than gasoline; 2) As noted, it's more energy-dense and therefore, depending on pricing, a better value; 3) For my road vehicles I can go a LOT further with a tank of diesel (racked up over 800 miles with one tank of fuel in my previous TDI- about 16 gallons, a bit less); 4) Diesel is the backbone of doing work and thus is going to exist for a lot longer than gasoline (yes, "they" are trying to kill* diesel but there's really no alternative for the shipping/trucking industry, not like there is for the automotive world). This is MY rationale, MY decision-making based on MY understanding of the risks for ME. Given that I'm older I would prefer to spend my time using equipment rather than working on it (I accept doing all necessary maintenance). I am not buying equipment to pass along to someone else, to a museum.

* But Mazda (new 3.3L diesel in 2023) and Scania (Swedish truck manufacturer keeps coming out with newer diesels- current ones don't need/use DEF or DPFs) didn't get get the memo. These companies are keeping diesels alive and I thank them for that.

End of my "2 cents worth," er, a, "5 cents worth"... Have work to do!

 

[Bentrim]

I admit I have not read all the posts. Here is my quarter. Danged inflation, used to be two cents!
Haveing worked on gas and diesel engines, no not the modern computer controlled but the older stuff.
The gas engine has many ways to get the fuel in the cylinder, carburetor, the old "sloppy mixer" it is a poor way to maintain even distribution to multicylinder engines and at all speeds. TBI or port injection injects fuel into the air stream before it enters the cylinder, Now they are using direct injection where the gasoline is injected in the cylinder just like a diesel. All most all types of fuel injection needs a computer to control the system, that is except the mechanical injection used in the 50's on Chevrolets.
The older diesels used a rotary or inline injection pump with one injection per combustion cycle. There are at least two types of fuel injection used. 1. Direct injection where the fuel is injected in a combustion bowl designed in the piston head. Easier cold starting but noisy (diesel knock)
2. Indirect injection the fuel is injected into a "power cell" (sorry forgot the name for it) they injectied the fuel into a cell that then the expanding, burning fuel traveled into the cylinder. They usually used a flat top piston. Harder to start in cold weather but quieter. Usually equiped with a starting aid or glow plugs.
Newer diesels are called common rail, were the "common rail" is presurized to a very high pressure and the injection is computer controlled and can have many, and varried length of injections per cycle.
Since they are computer controlled they are easier to start cold, and are quieter. Also are better pollution controlled.
Not familiar with but in the Army the trucks were equiped with multifuel engines.
Also check out the statified charge engine.
In the years I worked at a farmachinery dealer we sold and serviced Nuffield tractors. The first diesel I saw that used a throttle plate in the manifold. They used a BMC diesel.
The only other diesel was a detroit with an emergency shut off on the blower. It was driver activated by the driver in case of engine run away.
With a diesel be aware if excess oil enter in intake air you will have no throttle control and the engine will run away. The only way to shut it off is restrict the air entering the engine.
Guess thats my quarters worth.

 

[DarkBlack]

This is not hard to figure out even though it could have been more plainly stated. Most newer engines have overhead cams that are in the head vs the old style where the camshaft was in the block.

? Overhead camshafts are not a requirement for a gasoline engine.
Early pre-1980 , that I was responding to…gasoline engines were predominantly push rod.
There’s diesel engines with OHC

Where’s the overhead cams and high parts count on a gasoline 1968 chevy 350? A 1985 Briggs and Stratton single cylinder gasoline engine? More parts and more complicated than a diesel?

Then there’s 2 stroke gasoline engines with far less parts than a diesel, but that’s another subject

 

[DarkBlack]

I don't see anything about "early engines" in bmaverick's original statement.

Try again

 

[Bentrim]

Diesel was interested in using coal dust[32] or vegetable oil as fuel, and in fact, his engine was run on peanut oil.[33] Although these fuels were not better replacements, in 2008 the rise in fuel prices coupled with concerns about remaining petroleum reserves, led to the more widespread use of vegetable oil and biodiesel. Rudolf Diesel - Wikipedia
As for camshafts whether overheard or pushrod Navistar formerly IH was working on a cam shaftless engine where the valves were activated by electric solenoids, guess it didn't work out as I have not heard anything about it for years.
As for the number of parts Minneapolis Moline used a cross valve engine that is supposed to have the fewest parts of a gasoline engine. Long rocker arms activated by the cam opened and closed the valves. And it was the only engine you could work on that you did not have to crawl underneath to work on, they used a side cover.

 

[pmsmechanic]

Try again

View attachment 3504688

I was referring to post #150. It's pretty hard to see something that isn't there.

 

[pmsmechanic]

? Overhead camshafts are not a requirement for a gasoline engine.
Early pre-1980 , that I was responding to…gasoline engines were predominantly push rod.
There’s diesel engines with OHC

Where’s the overhead cams and high parts count on a gasoline 1968 chevy 350? A 1985 Briggs and Stratton single cylinder gasoline engine? More parts and more complicated than a diesel?

Then there’s 2 stroke gasoline engines with far less parts than a diesel, but that’s another subject

You made my point exactly. Thank you.

 

[CalG]

Sleeve valve engines have no cam shafts.

 

[Grumpycat]

Sleeve valve engines have no cam shafts.

Yes, like that dastardly complex modern gasoline engine on my chainsaw.