3 cyl. vs 4 cyl.

[_RaT_]

I can agree to agree with this. I haven't priced the big 3 but if you see them close to the same price then I would call that a marketing thing.

Since I have a Ford I hear more about the PSD, last I looked the I-6 24v cummins was still a fairly plain engine, inline injection system, turbo, straight 6. It is JMHO that this engine is cheaper to build than the International PSD and the Isuzu Duramax. It is amazing what they get out of that engine with little changes over the years. I wish I had the 24v.

Rob

I think you are right Rob, on all accounts. I would prefer the Cummins diesel in any truck I bought. I am sure the price we see being displayed for the diesel option is probably a marketing thing. I was driving aound today in my anemic Ford IDI 7.3 non turbo wishing for a gas engine. Now thats bad...

 

[Farmwithjunk]

Regarding cost to build vs price, we don't know if Cummins can build their 6 cheaper than the GM V-8 or the Ford V-8. I don't have a problem if the can build it cheaper and still sell it at the same price. That's just the free market at work. What I do know is that we want all three companies to make a REASONABLE profit so they can stay in business, stand by existing products and improve them for the future with some of that reasonable profit plowed back into R & D.

IMO it would stand to reason that all things being equal (which they usually are not), it would be cheaper to build a 3 cylinder engine vs a 4 cylinder simply because of fewer parts to manufacture and less assembly time installing those fewer parts.

Bottom line is it's still academic.

I agree completely. Number of cylinders=cost to build is an interesting theory, but we all know theories and realities aren't one in the same. A great deal of the potential for profit depends on business managment. It's possible that Briggs & Stratton can make a better percentage per unit on a single cylinder lawn mower engine than any of our favorite diesel engine builder can do on a multi-cylinder tractor engine.

In the end, it doesn't make one I-ota of difference how much $$$$ they make. It's all about what WE PAY for their prduct

 

[lawn_king]

I had a kubota 3 in the past, i now have a 4, both are great engines, both have lots of power, either way both great deisels, as is my isuzu 4 and my international 8.

 

[RobJ]

Since you are quoteing me. The inherient bal of a multiplane crank and the reaction to power pulses are not the same thing. Single plane cranks are not as smooth as multiplane cranks. Some auto 4 cyl engine have counter rotating weights to help improve the smoothness of the engine in addition to the counterweighted crank.

If you like do a search on single plane cranks. Here are a couple excerpts from various sites.

From Jag on their new V8.
"Purpose designed four valve V8 racing engines use a single plane crankshaft (like an in-line four cylinder) to obtain evenly spaced firing impulses along each bank to allow for optimum exhaust tuning, the downside being that the engine shakes laterally because of unbalanced forces"

From Truth about Cars. This site is biased towards V8's
"In contrast, inline four cylinder engines are inherently unbalanced. Because of the geometry of the crankshaft and rods within the engine, fours shake in both the horizontal and vertical planes. There’s only one way to mitigate the effect: add unbalanced shafts to create counter-vibrations."

From United States Patent 4974449
"A new balancing procedure for dynamically balancing the crankshaft and reciprocating parts overcomes the vibration forces produced by the high moments of inertia inherent in reciprocating engines with a single plane crankshaft"

This isn't no big thing for me and not trying to raise a fuss. Just pointing out other factors to consider.

Good research! All the 4 cylinders diesels I rebuilt had crank counter weights and did not have counter rotating shafts. These cranks were balanced on rotating lathes, although the weights were drilled to balance them, I never saw one that needed some correction. Perhaps some of the points in the atricles relate more to a high revving gas engines. Our diesels including my Kubota keep the rpms at 3000 or less.

 

[RobJ]

And re-read MY post if you would, carefully too. You'll not see where I said it was 20% better because it was 20% more expensive. It WAS/IS a better tractor without a doubt. MUCH better engine performance. No comparison. What I was commenting on was the fact that with ONLY the change of engine configuration, there was a 20% price increase in one single model year. That would be economic suicide for any reason without a marked improvement in the tractor itself. The price increase was the direct result of increased production cost passed on to the end user. Instead of commiting suicide, they then produced what was the worlds best selling line of utility tractors of its day. When the price increase came down, the engine change was still brand new.

Popularity had NOTHING to do with the increase, seeing as to how no one knew what sort of tractor the Perkins powered Masseys would turn out to be.

In actuality, with the dramatic increase in fuel efficiency, longevity of the engine, and extremely good resale value of Massey's smaller utilities (those with Perkins diesels) I'd venture a subjective guess it was substancially MORE than a "20% better tractor", but that's just my opinion..... And that of several million others who bought new Masseys back then, over other popular brands.

Not sure where you're from, but Masseys of that era were far less expensive than most anything else on the market. I shopped them out with every major brand. John Deere 2020's sold for almost $1000 more. IH 454 was higher than that. To this day, Massey's strongest selling point is they're less expensive than competing brands.

And if "no one had them because of that", please explain why the 135 Massey was the worlds best selling tractor throughout it's production run. Why is Massey STILL the best selling brand of tractor worldwide, ESPECIALLY in underdeveloped (read empoverished) countries?

BECAUSE THEY AREN'T a "rich mans tractor". No idea on this earth where that comment came from. Certainly not from facts as they present themselves.

You're expressing opinions, where I'm merely commenting on facts backed up with solid sales numbers, (along with solid RE-sale numbers) and MILLIONS of happy owners worldwide.

Good post, thanks for taking the time FWJ. The tractors I grew around were no less than 95hp so the MF 135 while popular couldn't do much work in the cotton fields. I guess I would say the rich mans comment came from hanging around my Granddaddy. He was a JD man and others in central Mississippi farmers had Internationals. My BIL had a MF 1080 (90hp?), it was sort of a beater tractor with some bad hydraulics. I rebuilt the big 4 banger perkins on it once. The fuel system sucked (air that is). The low pressure fuel lines had these rubber grommets that always caused problems. In 4 years he had the pump rebuilt 3 times. He traded it in not running condition. I think it was in rough shape when he bought it. He replaced it with another 25-30yo tractor, a Ford 6000. On that one I think he paid a LOT of money for 4 new tires and a nice paint job. Are you following me here??

Since you have a mess of MF tractors...I promise I won't talk bad about them again!!

 

[whitetiger]

One very big facter that resulted in 3 cyclinder popularity with manufacture's is that a number of the parts are interchangable with the larger 6 cyclinder engines. Less different parts to make, test, design and stock.

 

[Farmwithjunk]

One very big facter that resulted in 3 cyclinder popularity with manufacture's is that a number of the parts are interchangable with the larger 6 cyclinder engines. Less different parts to make, test, design and stock.

My "beloved" little Perkins diesel 3-cylinders from the 135/150 and their 4 cylinder "big brother" in the bigger 165 shared almost every part EXCEPT the block, head, cam, crankshaft, exhaust manifold, and injector pump. Valve train parts, pistons, rods, rings, bearings, cylinder sleeves, oil pumps, ect were all the same part #'s. In that manner, production cost was lowered for BOTH engine models, as well as reduced inventory for dealers stocking parts for each. Both of those diesels were ALSO available as gas engines. They shared most of the same parts as their diesel counterparts. A quick look through parts manuals show the blocks,cranks, pistons, rings, bearings, ect to have the same part #'s. That "commonality" also helped to lessen the need for seperate "special tools" at the dealers. That mentality carried through the entire tractor. The MF 135 and it's bigger relatives were designed and built with simplicity of service as a theme. That's why they were as popular as they were with small farmers in lower income areas. The "average Joe" could do 90% of their own repairs. Try that on the latest crop of plastic/electronic/hydrostatic/computer controlled technological wonderdogs.

 

[john_bud]

My "beloved" little Perkins diesel 3-cylinders from the 135/150 and their 4 cylinder "big brother" in the bigger 165 shared almost every part EXCEPT the block, head, cam, crankshaft, exhaust manifold, and injector pump. Valve train parts, pistons, rods, rings, bearings, cylinder sleeves, oil pumps, ect were all the same part #'s. In that manner, production cost was lowered for BOTH engine models, as well as reduced inventory for dealers stocking parts for each. Both of those diesels were ALSO available as gas engines. They shared most of the same parts as their diesel counterparts. A quick look through parts manuals show the blocks,cranks, pistons, rings, bearings, ect to have the same part #'s. That "commonality" also helped to lessen the need for seperate "special tools" at the dealers. That mentality carried through the entire tractor. The MF 135 and it's bigger relatives were designed and built with simplicity of service as a theme. That's why they were as popular as they were with small farmers in lower income areas. The "average Joe" could do 90% of their own repairs. Try that on the latest crop of plastic/electronic/hydrostatic/computer controlled technological wonderdogs.

Actually, the new ones are much easier; just swap out a wrench for a code scanner, plug it in, read the code - buy the replacement part, plug it in and go. Just like the techs do. Labor costs are quite high now, so plug and play is in vogue.

Now if you want to actually tear it apart and (gasp!) FIX something, you may need to get that wrench back.

jb

 

[Soundguy]

I wasn't refering to the crank.. but rather the power pulses. The reason a 4 is smoother than a 2, which is smoother than a 1 is the number of power pulses.

If you have 100hp being generated by a 1 lung.. and 100 hp being generated by an 8cyl... the 8cyl is gonna sound smoother.

As for the crank.. it's either in ballance ( ballancers ).. or it ain't. if it aint'.. it won't last too long before shelling out..

Soundguy

This was the original quote...

Don't overlook the fact the 4 cyl has a single plane crank and the 3 cyl has a 3 plane crank. The 3 cyl will be more inheritly in bal. All else being equal, the 4 cyl will have more but less intense power pulses.


Maybe I did misunderstand, but I read it as the 4 cylinder crankshaft has 2 journals up and 2 down, the 3cyl has 3 journals spaced out. I just looked at one of my head gasket replacement pics and the 3 are spaced around the circle (so to speak, in my pictures I have one piston at the bottom, one in the middle and one at the top of the strokes). So in his statement the crank itself it sort of balanced out, and that makes perfect sense. I just don't think that has a lot to do with it, all cranks I've seen have counter weights anyway, otherwise the engine would shake itself apart. As someone mentioned, 2 is smoother than a single, 3 better than a 2 cyl and so on.

Rob

 

[Egon]

Anybody here knowledgeable in Rotational Dynamics ??