3 cylinder vs 4 cylinder

[chriswheeler]

In my relatively short time owning and using tractors, I've owned 3 all in the 30 hp. range. a Yanmar 3000, a Deere 950, and the Deere 970. The first 2 were 3 cyl. and the one I current is a 4 cyl. All other things aside, starting on a cold morning goes to the 4 cyl starting in less than 1/2 revolution. The other 2 engines with 3 cyl. needed block heaters or pre-heaters under the same conditions. Running and operating goes to the 4 cyl. engine as well, smoother running as well. Nothing technical here, just real life. Every engine was a Yanmar and in comparable condition. I have less than 3000 hours total of seat time total with all 3. The 4 cyl happened as a consequence of trading up. Now,, if trading up, I would be looking for a 4 cyl. Some of the other members here have years of tractor operation here, not me. I'm still in the new operator class.
Chris

 

[zzvyb6]

I built a metal bracket from a cup holder to shake and stir the paint in new and used rattle cans. At low idle, my F935 3 cylinder does a great job of resurrecting paint that's been setting in my paint cabinet for a long time. When not shaking, I set the throttle up to the smoove setting.

 

[ruffdog]

Well, Not EVERY 120 degrees.
That would hold true if the engine was a two stroke.

True. The pistons come to TDC every 120 degrees but the power strokes are at every 240 degrees because they are 4 strokes. Three cyl engines have an issue with vibes because no 2 cyls are hitting TDC at the same time. You will have a engine that wants to rock end to end. Same with a parallel twin with a 180 degree crank. A twin with a 360 degree crank up and down but will not have the rocking motion. A 4 cyl is basically two twins with 180 degree cranks that balance each other out. A 3 cyl can be made to be somewhat smooth with the added cost of balance shafts and well designed motor mounts. My TC33D had a 3 cyl in it and I never thought it vibrated bad and it did not have a balance shaft. Was it smoother because the flywheel was heavier and it had large/heavy counterweights on the crank?

Here's The Problem With Three-Cylinder Engines

 

[RickB]

Few 3 cylinder Diesels have dynamic balancers. All but a few 4 cylinder Diesels do.

 

[BobG_in_VA]

We all remember the old adage, that "there's no replacement for cubic inches"....well, that's where the turbo charger (TB) comes in...a 3 cyl with TB may put out as much HP as a non TB 4 cly, and I'm pretty sure that 3 cly engines are "cheaper" for the manf. to build....I'd rather have a non TB 4 cyl putting out 60hp than a 3 cly putting out the same hp. For one thing, the 4 cly, with normal maintenance will most likely outlast the TB 3cly...also no cool down on the 4 cly. engine....just my 2 cents... BobG in VA

 

[Agvg]

We all remember the old adage, that "there's no replacement for cubic inches"....well, that's where the turbo charger (TB) comes in...a 3 cyl with TB may put out as much HP as a non TB 4 cly, and I'm pretty sure that 3 cly engines are "cheaper" for the manf. to build....I'd rather have a non TB 4 cyl putting out 60hp than a 3 cly putting out the same hp. For one thing, the 4 cly, with normal maintenance will most likely outlast the TB 3cly...also no cool down on the 4 cly. engine....just my 2 cents... BobG in VA

Diesel without turbo is a bad design, or any engine without turbo is a bad design if we are talking above lawnmowers

 

[Roadworthy]

I prefer my engines without turbos. I'd rather have more cubic inches to derive the power I want. I like simplicity and believe the turbo stresses the engine. I prefer the sound of a four cylinder engine but when push comes to shove for me three cylinders does the job just as well if the horsepower is there. I've always thought three cylinder engines were an oddity but they seem to be the norm in the small tractor world. I notice nobody brought up two cylinder engines though they have been used in tractors as well.

 

[RickB]

I've always thought three cylinder engines were an oddity

3 cylinder engines have dominated the utility tractor class since the mid 1960s.

 

[murphy1244]

And on the 7th day God introduces Perkins Diesels.

 

[Industrial Toys]

And on the eighth day he rested, for the Perkins gave him a splitting headache. They do me anyway.

I have a bunch of little Diesels that I am glad don't have a turbo. Just like I would never chip a p/u truck. Stock, slow and modest is right for me.

As far as 3 or 4 cylinders. I have a bunch of both, and can't really narrow down a characteristic that would apply to one or the other accross various brands. I know, part of me finds any odd number kind of weird. 3, 5, how about a 7? Never heard of that.