Common rail vs mechanical injection

[Cow pi]

Thanks for all the replies. It sounds like it's pretty much a wash on the injection system. Simplicity vs power and fuel economy.

The tractors I was looking at are all tier 3, so the DEF, DPF garbage isn't a factor.
The Case Maxxum pro has CR and was tier 3 until 2013 or so, and there are a few later Value series with CR as well.

I was looking at the 120HP range Massey Ferguson/ Challenger too. They started using CR around 2007 or 2008, so there are quite a few years of them in tier 3.

 

[rScotty]

Thanks for all the replies. It sounds like it's pretty much a wash on the injection system. Simplicity vs power and fuel economy.

The tractors I was looking at are all tier 3, so the DEF, DPF garbage isn't a factor.
The Case Maxxum pro has CR and was tier 3 until 2013 or so, and there are a few later Value series with CR as well.

I was looking at the 120HP range Massey Ferguson/ Challenger too. They started using CR around 2007 or 2008, so there are quite a few years of them in tier 3.

Can you give me a reference to Tier 3 standards? What years & HP did Tier 3 apply? I am familiar with the Tier 4 Interim that was used from 2007 to the end of 2012....but not familiar with Tier 3 at all. Maybe it's a different engine size.

Anyway, you might want to look at engines with the Tier 4 Interim as well. It turns out that our M59 is a Tier 4 Interim from 2008. They didn't have DEF or DPF and used mechanical indirect injection. Some had EGR assemblies.

I like the softer sound & simplicity of the older indirect injected diesels, but they do make a lot more smoke and soot.
rScotty

 

[Hay Dude]

Thanks for all the replies. It sounds like it's pretty much a wash on the injection system. Simplicity vs power and fuel economy.

The tractors I was looking at are all tier 3, so the DEF, DPF garbage isn't a factor.
The Case Maxxum pro has CR and was tier 3 until 2013 or so, and there are a few later Value series with CR as well.

I was looking at the 120HP range Massey Ferguson/ Challenger too. They started using CR around 2007 or 2008, so there are quite a few years of them in tier 3.

You might be able to get one of the AGCOs (Massey, Challenger, AGCOs) with a CVT. I have a 7495 and love it.

 

[Boss 302]

You can also view it this way:
Mechanical is easy to troubleshoot, generally very dependable trouble free
Common rail = computer driven, trouble codes, downtime is usually greater

 

[rScotty]

Can you give me a reference to Tier 3 standards? What years & HP did Tier 3 apply? I am familiar with the Tier 4 Interim that was used from 2007 to the end of 2012....but not familiar with Tier 3 at all. Maybe it's a different engine size.

Anyway, you might want to look at engines with the Tier 4 Interim as well. It turns out that our M59 is a Tier 4 Interim from 2008. They didn't have DEF or DPF and used mechanical indirect injection. Some had EGR assemblies.

I like the softer sound & simplicity of the older indirect injected diesels, but they do make a lot more smoke and soot.
rScotty

Never mind, I figured it out. Or at least partly, the emissions regs are complicated and full of special case exemptions.

Basically engines over 75 hp had until 2012 to get 25% of their engines to meet to meet the Tier 4 emission requirements. Then in 2015 all engines 75 hp had to meet Tier IV requirements - unless they fit some of the many pages of loopholes...including something called "banked compliance credits". Tier 4 Interim for our Kubota M59 uses one of those "loopholes" for pre-existing engines.

So until sometime between 2012 to the end of 2014, it looks like most diesel engines could be Tier 3 - just as you said. The emission restrictions didn't amount to anything on those engines and so they could use mechanical injection with an indirect injection head configuration.
Most of the reduction in emissions during this time was due to changes in diesel fuel, not to diesel engines.

After 2015, ALL diesel engines had to meet the present Tier 4 standards (unless they meet pages and pages of exceptions and alternatives). Most manufacturers met Tier 4 requirements by changing to direct injection engines having computer control, plus some sort of emission reduction system.

BTW, a footnote in the regs says the goal is that by 2030 when all diesel engines are Tier 4, 12,000 premature deaths per year will be prevented by the reduction in diesel emissions.

https://dieselnet.com/standards/us/nonroad.php

rScotty

 

[Fielding]

Still don't understand the maintenance argument electronic vs mechanical. Only diesel issues I have ever had have been the old mechanical ones. The mechanical pumps run really rough on a good day too.

We sell off our fleet trucks at 600,000km none have had engine issues since cummins went electronic.
No Turbo issues either.

The tractors on the farm are the same story, the new stuff is great.

at 2200’ asl Turbo is a wonderful thing to have.

Don't overthink it, just drive them.

 

[Boss 302]

Yup, I love my new powerstroke diesel with all of the things that can and will eventually fail it has awesome power. I also was very fond my old 7.3 mechanical injection truck that was as simple as it gets and without a doubt one of the most reliable engines ever put under a hood.

 

[Haasman]

From my limited experience with direct injection, it is great. All the positives but the fuel pumps are quite expensive to replace. The common fuel rail has to be pressurized at high PSI in order to properly atomize the fuel across the injectors.

We had a German car that also had DI, its pressure was 1600 PSI. A pump that reach those levels doesn't come cheap.

Haasman

 

[Boss 302]

Reminds me of all the horror stories with the Bosch fuel pump used on the new Ford powerstrokes, when they fail due to (mostly water in fuel) it isn't covered under warranty and comes with a price tag of around 10k. OUCH!

 

[RoostersGarage]

I've noticed that properly running mechanic pump diesel starts a whole lot quicker than a common rail. My grandpa's 1974 John Deere 830 with it's German-made diesel starts within 1 second regardless of temperature - I don't know what they did to make it work so well but I just keep it supplied with clean fuel. Also my buddies 12v Cummins starts quicker than either one of our 6.7 Cummins. I don't know for sure, but it seems the sensors need to see a couple rotations to be sure of the speed where the mechanical just works no matter the speed.