High horse power four cylinders can’t sustainably do the same job as a larger six pot of similar HP. Tell me I’m wrong

[Hazza6930]

If used as a replacement to a larger six cylinder tractor of around 160 HP with the same kit. Increased engine wear, brakes and transmission. Turbos blown? High service costs ? Overall will they take the wear and tear as well as a larger six ? I know a lot are buying these four pots to replace there old six but and just weighing them up. How will they be with some hours under the belt. Give me your thoughts

 

[Two Tone]

Multiples or 3 or 5 cylinder engines are far better and more efficient than any 4. For the simple reason that the engine fires more than once on every 1/2 crank rotation. In a (straight) 6 cylinder engine, the engine fires every 1/3 of the crank‘s rotation, being 50% more often than a 4 cylinder engine. Therefore they have more momentum and run more smoothly.

When Turbos first became popular, a turbo’d 4 cylinder could be superior to a non turbo’d 6 of the same HP.
Put a turbo on both and the 6 will always win when the total cc capacity of both engines is the same.

.

 

[Against_the_grain]

You are not wrong. The 150hp(ish) 4cyl engines are just gutless work harder and have no torque. Don't do it.

 

[DrDunc]

Today you're comparing 4 and 6 pot 160hp and looking to start an argument that the 4 pot is pish in comparison

Very few years ago the exact same pointless pontifications were being made about 120hp

Go figure

 

[Hazza6930]

Today you're comparing 4 and 6 pot 160hp and looking to start an argument that the 4 pot is pish in comparison

Very few years ago the exact same pointless pontifications were being made about 120hp

Go figure

I don’t see how it’s pointless ? It’s a valid point questioning reliability and engineering today not years ago. No drama just discussion

 

[Mur Huwcun]

The only thing limiting them really is their wheelbase! They won’t lift/carry so much and not so stable on a trailer.

 

[ollandroverman]

The only thing limiting them really is their wheelbase! They won’t lift/carry so much and not so stable on a trailer.

4 Cyl Valtra N174 weighed around the same and had same wheelbase as JD 6930 when i looked.

 

[J 1177]

Got both, little difference in performance. When the 6420s jd came out the same could be argued about them, turned out to be one of the best deeres ever made

 

[Farmer_Joe]

Got both, little difference in performance. When the 6420s jd came out the same could be argued about them, turned out to be one of the best deeres ever made

Ive had/driven both, 4 cylinder now gone, there were much of a muchness on flat but when you got lugging on a hill (especially with pto work going up hill) and the 6 cylinder would eat it alive, thats a 2007 mf 6 cylinder vs a 2012 4 cylinder jd both 125 bhp.

depends if you have really flat land you would prob be ok with 4.

 

[Mur Huwcun]

4 Cyl Valtra N174 weighed around the same and had same wheelbase as JD 6930 when i looked.

Most probably but how does it compare to the 6 cyl Valtra equivalent then.

 

[fendtfiasco]

In Massey Ferguson a 6715 is a four cylinder but in a 6480 chassis so its actually the same wheelbase as a six cylinder, power and torque might be higher up the rev range, however its a 4.4 litre engine the top Valtra 4 cylinders are larger capacity. Whereas a MF 398 WAS 3.860 LITRES.

If you compare it to cars a Ford Sierra Cosworth was 2 litres with 204 hp, a RS500 was 224 hp now a VW Golf R is 320hp and a Merc A Class AMG NOW 421 HP.
Better machining and materials and engine management etc pushes power up out of smaller engines.

 

[balerman]

The only thing limiting them really is their wheelbase! They won’t lift/carry so much and not so stable on a trailer.

The wheelbase is the same for 4 and 6 pot nowadays if you want from most brands. I wouldn’t mind betting the torque figures from a new 4 cyl 150hp tractor would be higher than a 150hp 6cyl from say 15 years ago,it’s just how it is now.

 

[Mur Huwcun]

The wheelbase is the same for 4 and 6 pot nowadays if you want from most brands. I wouldn’t mind betting the torque figures from a new 4 cyl 150hp tractor would be higher than a 150hp 6cyl from say 15 years ago,it’s just how it is now.

Unless they have a full chassis or a spacer they won’t be exactly same length though, the idea of the 4 cyl is to be compact with tighter turning circle and they will still have a little less weight up front. 9” difference between Fendt 516 and 716 for example.

 

[balerman]

Unless they have a full chassis or a spacer they won’t be exactly same length though, the idea of the 4 cyl is to be compact with tighter turning circle and they will still have a little less weight up front. 9” difference between Fendt 516 and 716 for example.

Case Maxxum and NH T6 do have a spacer so they are identical to the 6 cylinder.

 

[Farmer_Joe]

In Massey Ferguson a 6715 is a four cylinder but in a 6480 chassis so its actually the same wheelbase as a six cylinder, power and torque might be higher up the rev range, however its a 4.4 litre engine the top Valtra 4 cylinders are larger capacity. Whereas a MF 398 WAS 3.860 LITRES.

If you compare it to cars a Ford Sierra Cosworth was 2 litres with 204 hp, a RS500 was 224 hp now a VW Golf R is 320hp and a Merc A Class AMG NOW 421 HP.
Better machining and materials and engine management etc pushes power up out of smaller engines.

Ha ha I always remember cosworth being the dogs when you look back now there very average power wise amazing some of the powers available on 4 cylinder turbo cars still there not as fun as v6 /straight 6 and sound no where near as good, like tractors

 

[Rob Holmes]

Got an MF 6470 and 6480 here and pulling performance is very similar

 

[TripleSix]

There's no replacement for displacement.
There ain't no substitute for cubes.

 

[Phil P]

In Massey Ferguson a 6715 is a four cylinder but in a 6480 chassis so its actually the same wheelbase as a six cylinder, power and torque might be higher up the rev range, however its a 4.4 litre engine the top Valtra 4 cylinders are larger capacity. Whereas a MF 398 WAS 3.860 LITRES.

If you compare it to cars a Ford Sierra Cosworth was 2 litres with 204 hp, a RS500 was 224 hp now a VW Golf R is 320hp and a Merc A Class AMG NOW 421 HP.
Better machining and materials and engine management etc pushes power up out of smaller engines.

It’s not all about hp though, I had a 1L super bike that made 180bhp but I wouldn’t want to use that engine to drag a trailer, cultivator, drill etc. It’s getting the balance between hp and torque right that makes a good engine and in ag applications you want a lot of torque as that’s what does the work.

 

[Wellytrack]

Thank goodness the internet did not exist in the format it does now in 1994 or we could be delighting in discussing if a 95hp 4 Turbo can match a straight 6

People are reassured by the thrum of a nice steady even running six cylinder but that’s harking back to different times.

Unless 4’s or 6’s of equal make and claimed power are put on the Dyno it’s pointless comparing them as with modern tractors what is claimed is nothing like what is delivered.

A 150hp 4 can and will outperform a similar 6 cylinder. It’s also possible the 6 will beat the 4. Any Dyno results I’ve seen show stonking amounts of torque at 1200 rpm from modern 4’s.

 

[Cowabunga]

If used as a replacement to a larger six cylinder tractor of around 160 HP with the same kit. Increased engine wear, brakes and transmission. Turbos blown? High service costs ? Overall will they take the wear and tear as well as a larger six ? I know a lot are buying these four pots to replace there old six but and just weighing them up. How will they be with some hours under the belt. Give me your thoughts

You are wrong. The four will be more efficient, will have sharper response and recovery, will be just as reliable while being cheaper to run, maintain and repair. Engines tend to last longer than ever before, no matter how many cylinders. Some are not, but their six cylinders are equally as unreliable as their four cylinder engines. But at least the four only has four of every main moving part.
The torque and torque rise, and even the start-off torque of most four cylinder engines today at least equal that of the six cylinder version of the same horsepower from the same engine family.
Just look at how far car Diesel engine have advanced in recent years. The same goes for tractors. My 2.0 Volvo four cylinder engine was 20% more powerful and 30% more torque at similar low revs to my 4.2 litre turbo-intercooler Land Cruiser engine and uses literally half the fuel to go way faster with less noise as a bonus.