Easier engine to work on diesel-gas

sandman2234 · Jan 14, 2006

Another thing that compares gas to diesel is the horsepower. What would seem to be equal, isn't .
A diesel tractor with equal horsepower will outwork it's gas counterpart any day of the week. I have a 13Hp diesel tractor that will outwork 20 to 25 hp gas all day long.
Doesn't make sense, since the rating of a horsepower is a constant, but maybe the torque rating is what gives it that little extra bit of working ability.
David from jax

Soundguy · Jan 15, 2006

( I have a 13Hp diesel tractor that will outwork 20 to 25 hp gas all day long.
)

I find that a tad hard to swallow.

While I would expect a 20hp diesel to have a bit more 'nads' than a 20hp gasser.. I'd expect them to both do about the same work.

Your example of a 13hp rated diesel outworking a 25hp rated gas.. all day.. just doesn't pan out.. unless you are talking about a 25hp lawnmower.. vs a SCUT 13hp diesel tractor... like a small yanmar 1100/1300 or small BX1500.. etc.. Then yes.. I'd believe you.. lawn mowr engines use some wildly imaginitave ways to arrive at 'marketed' hp.. vs tractor hp ratings being more or less 'real'..

It's a sad fact that my 26 hp gas 8n would outwork my 21hp yanmar 1700 for pulling, and mowing. A 5' rotary mower was just too much on the yanmar.. yest the gasser pulle dit.. and we are talking 5 hp difference.. and one of the tractors is 27 ys older than the other... that's a way different comparison than 13 vs 25 .. etc..

Soundguy

sandman2234 · Jan 18, 2006

We could argue this point all day, or I could put you in touch with the owner of the gas tractor, or we can both agree to disagee. Me telling you something you don't believe isn't going to make you a believer, so there really isn't a point to it.
Guess the same thing goes with diesel trucks. A 280 hp gas should pull the same loaded trailer up a mountain as a 280 hp diesel. As far as my 13Hp Ford 1100 4x4 is concerned, it is one hard working tractor.
David from jax

Soundguy · Jan 19, 2006

( or we can both agree to disagee. Me telling you something you don't believe isn't going to make you a believer, so there really isn't a point to it. )

Your'e right.. I'm not going to believe that a 13hp rated diesel tractor outworks a 25hp rated gas tractor 'any' day.. let alone all day.

This assumes both are real tractors.. I.E. one of them isn't a lawnmower.. and that both are refering to a bona-fide hp rating system, either engine, drawbar, or pto, and that both are in average or better 'shape'.

I think the weight issue would also be a concern... it takes weight to do work.. that is.. to get hp to the ground.. it takes enough weight to keep the tires from slipping.

You saying that 13hp tractor is heavy enough to pull the same weight and size disc harrow as the 25hp gas tractor?

Everything else aside.. lets show cards.. what are the makes and models if this 13hp diesel ( ford 1100? ).. and what about the gasser 25hp unit?

Soundguy

HGM · Jan 19, 2006

Could we be refering to ease? This isnt my debate, but I would like to add a little for thought..

A 26hp gas tractor can likely do the same work as its diesel equal(HP and weight wise). However it stands to reason that the gas unit would have to work harder and keep the RPM's up in order to perform the same work. The diesel is designed with more Tq providing easier access(so to speak) to the power.

I dont really dissagree with either one of you, rather I am somewhere in the middle....I would think that a 26hp diesel Ford or JD could easily outwork a 26HP 8n. They could probably do the same work, just not as easily with the 8n.... I look at a 310hp V10 F-350 vs a 325hp 6.0L for comparison in my mind. The diesel will maintain a greater speed than the gas burner under a load on a steep grade, but they are both capable..

Soundguy · Jan 19, 2006

Gotta look at 'rated' hp.. if we are talking pto hp.. then we are also talking about a set engine rpm making that rated hp.. thus 'ease' is harder to quantify.. since both engines will be running at throttle.

As my point was earlier.. My diesel 21/17 hp yanmar 1700 would lug pulling a 5' roatry mower in bush.. that is.. more throttle did not equal more rpm... Same with pulling a heavy pasture drag... Had more movement onthe throttle available.. but no more rpms = lugging. Sadly.. the 54 year old 8n ran the mower fine, and would throttle up to the 1800's under load even though pto rpm was 1500's... same with the drag.. in a similar speed.. /forums/images/graemlins/blush.gif

I'd expect similar hp gas and diesel engines to lend a bit more 'oomph' to the diesel. as you mentioned. A gas 26hp setting next to a diesel 26 hp.. I'd kind of expect the diesel to have a bit more 'reserve' so to speak.

The other issue is age and condition.. When you are compairing for instance.. a 54 year old '26' hp 8n to a modern 26 hp diesel.. you may in fact only have a 20-22-24 hp 8n due to lower compression.. etc.. if you rather compaired similar hp gas and diesel, and similar condition.. ratio of compressionloss.. I think you may find that for equal hp.. the gasser will set just a hair under the diesel for 'work ability.

Soundguy

HGM · Jan 19, 2006

I can agree to that... Sorry, I know you werent looking for my approval.. Just thought I'd add that Tq and powerband are as important as HP(if not more so)..

Soundguy · Jan 19, 2006

I wasn't looking for approval.. just facts.. I notice that no tractro info appeared...

Tq and hp as they relate tot he power band are going to have to be compaired in the context of reated rpm.. for instance.. pto hp has to be compaired with both tractors running at rated pto rpm.. etc IMHO.. pto rpm should be in the power band.. or the tractor manufacturer isn't doing their job correctly.

Given all that.. I'll ask again.. what 25hp gas tractor do you have that will run less of a pto load at rated rpm than a 13hp diesel tractor on that same load.. again.. asuming equal or similar condition of tractor.. I.E. same ratio of compression loss.. etc. ( In other words.. we can't compair a 99% worn out on-its-last-legs 60 year old gas tractor to a 25 year old 'in-spec' diesel, for a real comparison.. etc.

Soundguy

RobJ · Jan 19, 2006

If you are comparing an older 8N style gas motor to a cut type diesel then the gas is much easier to "work on". Remember this term "work on".

Bottom end we'll call it a wash, both have cranks, pistons, etc. Both should be put together to specs. The diesels will be heavier and more expensive in most cases. For an 8N new parts are still made everywhere.

Fuel system. This is where the gas is easier to work on. The diesel you must send the pump and injectors to a shop where they have the proper test equipment. Carbs you can toss in a kit or some some small bucks (compared to a new injection pump) put on a new carb. The carb is something you can actually work on.

Electrical, granted a diesel doesn't have a sparking system but it may have glow plugs that need to work. Price a glow plug? Points and condensor and spark plugs are pretty cheap and can be picked up at most any auto parts store. Again you can "work on" these. A properly set of points and plugs will last a very long time. How many have worn out a Briggs engine and never replaced the points? And I don't think I've ever replaced a "bad" coil.

Gas engines are usually a lot cleaner to work on. No black soot stained everywhere.

I use to work on diesels and gas engines. Even the small 1,2,4 cylinder Wisconson and Robin engines. A one cylinder is just as easy as a 2 or 4 cylinder. You have to get it correct for it to work. Most don't see much glamor in working on a 1 cylinder gas sewage pump so the time isn't spent on it like a mighty 8N tractor. /forums/images/graemlins/grin.gif There is more glory there.

I did end up buying a small diesel tractor. But if a gasser came along with the deal I got I might have considered it. I was tied more to the deal I got than what I got.

Rob

Farmwithjunk · Jan 20, 2006

I started to stay away from this topic altogether. I'm not sure there is even a real answer. But never known as one to keep my opinion to myself, here we go.

I've read the entire thread. I have a few comments on some particular "statements". I'm not going to address each one, but those who are involved know their side.

First off, Horsepower is Horsepower. 25 HP gas is the same as 25 HP diesel, is the same as 25 HP electric. Each has its particular "advantages", but power is power. I don't know of any cases where a simular powered gas engine and a diesel of the same size and HP have the same torque curve and such, but I know of a few cases where the gasser has a DEFINATE HP advantage over a diesel of the same exact size (cu. in. displacement) Diesels are more efficient, and USUALLY have better power characteristics (i.e. torque, "reserve power", ect) But that isn't carved in stone anywhere. The arguement over "25 HP vs. 12 HP" needs to be apples vs. apples. The tractors in question must be of the same weight, gearing, doing the same chore, operated by the same person to compare accurately. (And I've yet to see in all my days, an engine of half the horsepower outwork one twice its size under most any conditions)

Both require a certain amount of routine maint. over their lifespan. Diesels are less involved come tune-up time. But generally, fewer people know all that's involved with maintaining a diesel PROPERLY.

With gassers being more common (cars, trucks, ect), more people are familiar with the workings of a gas engine. The "average Joe" can learn the basics of gas engines. It takes just a tad bit more to learn the workings of a diesel. BUT....Once you learn how to work on diesels, they are infinately less complicated.

And I'd take a well maintained diesel over an equally well maintained gas engine any day of the week.

"easy" is such a relative term. Easy to who?