Injection

[Beavis]

While shopping for tractors, one thing I've noticed is that some motors state that they have/are "direct injection" (John Deere) and others state "indirect injection" (Mahindra) Can you tell me what the difference is and what an owner/operator would notice?

THANKS

 

[ccsial]

While shopping for tractors, one thing I've noticed is that some motors state that they have/are "direct injection" (John Deere) and others state "indirect injection" (Mahindra) Can you tell me what the difference is and what an owner/operator would notice?

THANKS

The older diesels injected fuel into a pocket that ingited the fuel. This was called indirect injection. The newer injectors put fuel directly into the cylinders and this is called direct injection. I believe the direct injection is more efficient and also make the engine run a bit quieter.

I think the new injectors atomize the fuel better and don't need that hot pocket to ignite it.

Somer of the new diesel engines use electronic injectors and have multiple injections during one power stroke to make the engine smoother and quieter. I don't think tractors are using this technology yet.

I read about this a few years ago but I don't remember it all. I'm sure some real experts will post more on this though.

 

[Z-Michigan]

ccsial is correct. Direct injection is a more high-tech way of doing things and is slightly preferable. However, this is not a significant issue for diesel engines in the 50hp and under range. Some of the top tier makers, such as Kubota, still use indirect injection, and it works fine. I wouldn't consider this a decision point in your purchase, however I would look up the Nebraska tractor tests for the models you're interested in to see if one model is noticeably more efficient than others.

 

[Egon]

Indirect engines will usually have Glowplugs while direct injection engines must use some other form of preheat involving the air or fuel.

 

[john_bud]

The older diesels injected fuel into a pocket that ingited the fuel. This was called indirect injection. The newer injectors put fuel directly into the cylinders and this is called direct injection. I believe the direct injection is more efficient and also make the engine run a bit quieter.

.

Actually, the older / newer delineation is sort of bogus. (No offense!) My "older" tractor with indirect injection is a year 2000 Kubota L3410. My "Newer" tractor with direct injection is a 1963 Ford diesel. That's about as backward as it gets! The Kubota is smaller displacement, fewer cylinders but runs as smooth, much cleaner, more efficient and has more HP, but less low end torque.


There are two ways of doing things and some companies have made one way work well, and other companies have made other ways work well. The ability to brag about one way being better is all marketing driven. The real improvements are due to high pressure common rail injection systems that run at 20,000+ psi. New Kubota engines are using that now.

Bottom line is look at the PTO HP, the operator layout, fit to your body, cost, weight and dealer support. How the engine is screwed together is essentially insignificant.

Just my $0.02
jb

 

[Beavis]

THANKS for all the information.

 

[Z-Michigan]

Indirect engines will usually have Glowplugs while direct injection engines must use some other form of preheat involving the air or fuel.

To be precise - you can have glowplugs with direct injection; my Jeep Liberty CRD (diesel) has that exact combination, and it's a high pressure common rail design. OTOH my Cummins ISB (Dodge Ram) and my JD 5105 tractor both have manifold heaters. I know the ISB is also direct injection - I think the JD is too but I'm not certain.