Anyone seriously considering the R2.8? (Cummins)

[JamesAndTheSahara]

I'm curious to see if anyone is seriously considering doing this. At the end of my build I have full intentions of doing something to my engine and considering all options. It seems like it would be a smart switch for fuel economy but a poor switch for power. I'd love to see someone do a build thread of one on here!

 

[VallenMaes]

 

[Chris]

Nope. Modern diesels are nothing like their old predecessors. The new diesels have so many electronics and emissions, that in my opinion, it defeats the whole puprose of owning a diesel. I would much rather spend the money on a nice LS swap, where parts come by the plenty and for cheaper too.

After riding in a diesel TJ with the top off, I would also never do a diesel swap just based on that. It’s so loud you can’t even hear yourself think. Just sitting at a stop light was mind numbing.

 

[VallenMaes]

Not sure if this is the same engine but here is this.

 

[glwood]

Not sure if this is the same engine but here is this.

?

 

[JP98]

@VallenMaes Thanks for posting that Dirt Everyday episode. That new Cummins was way quiet and looks like a great fuel saver. Dang it!!! Now I have to add it to the short list of motors to look at when my 4.0 goes south.

 

[Reece]

Nope. Modern diesels are nothing like their old predecessors. The new diesels have so many electronics and emissions, that in my opinion, it defeats the whole puprose of owning a diesel. I would much rather spend the money on a nice LS swap, where parts come by the plenty and for cheaper too.

After riding in a diesel TJ with the top off, I would also never do a diesel swap just based on that. It’s so loud you can’t even hear yourself think. Just sitting at a stop light was mind numbing.

Not to mention diesel fuel is now more expensive than gas by a fair margin. You can thank the epa and ulsd fuel requirements for that one. This fact alone takes a huge chunk out to the "better mileage" reason the get a diesel engine.

 

[JP98]

Not to mention diesel fuel is now more expensive than gas by a fair margin. You can thank the epa and ulsd fuel requirements for that one. This fact alone takes a huge chunk out to the "better mileage" reason the get a diesel engine.

Diesel is running about $0.05 more than regular in my area and often drops below the cost of regular. The math could work out for some areas. I would swap out my 4.0L just for fun but if I she goes out then maybe.

 

[Reece]

Diesel is running about $0.05 more than regular in my area and often drops below the cost of regular. The math could work out for some areas. I would swap out my 4.0L just for fun but if I she goes out then maybe.

I dont begrudge anyone wanting a diesel. Hell, I've been running a 5.9L cummins in my truck for the last ten years. Love the power and the sound. I have pretty much a straight 5"inch exhaust on it, I will admit however that when the rust finally takes that 5" system I will get something more tame.

I just do not like the new ones.

 

[JP98]

Did read an article that sad there was an adapter for the R2.8 to the AX15 and NV3550. If I could swap out motor only with a little wiring it may not be too costly of a swap.

 

[Chris]

Not to mention diesel fuel is now more expensive than gas by a fair margin. You can thank the epa and ulsd fuel requirements for that one. This fact alone takes a huge chunk out to the "better mileage" reason the get a diesel engine.

I agree. I'm not saying diesel isn't cool... It is. However, the only diesels I like are the old diesels (i.e. 4BT, 6BT, etc.) where they were much, much simpler, easier to work on, and no overrun with electronics and sensors like all the modern diesels.

In my area diesel is also usually either the same price or more expensive than standard gasoline.

I just don't really see an advantage to running diesel over gasoline, unless you like the "cool" factor.

There are areas where diesel fuel might be cheaper than gasoline, but I think it's negligible at best. Besides, you'd pay over 10k for this swap, and how long would it take you to offset that money in relation to the amount of money you'd save on your more fuel efficient engine?

Sorry, but the math simply doesn't add up.

I think this Cummins swap is cool, but it's nothing I'd consider. Still, I look forward to seeing others do it.

 

[JamesAndTheSahara]

Nope. Modern diesels are nothing like their old predecessors. The new diesels have so many electronics and emissions, that in my opinion, it defeats the whole puprose of owning a diesel. I would much rather spend the money on a nice LS swap, where parts come by the plenty and for cheaper too.

After riding in a diesel TJ with the top off, I would also never do a diesel swap just based on that. It’s so loud you can’t even hear yourself think. Just sitting at a stop light was mind numbing.

What diesel was swapped into the vehicle? Was it the engine noise or exhaust that was mind numing? I just can’t imagine a 4 cylinder diesel being that loud.

Not to mention diesel fuel is now more expensive than gas by a fair margin. You can thank the epa and ulsd fuel requirements for that one. This fact alone takes a huge chunk out to the "better mileage" reason the get a diesel engine.

Diesel is running about $0.05 more than regular in my area and often drops below the cost of regular. The math could work out for some areas. I would swap out my 4.0L just for fun but if I she goes out then maybe.

The price is pretty close here in Alabama.

20-30mpg & a well suited power-band with great power at low rpm’s would make for a great combo. The main concerns I have seen are directly around noise, cost, why wouldn’t you choose a supercharged 4.0, stroked 4.7, LS Swap, turboed 4.0, ect.

 

[JamesAndTheSahara]

I agree. I'm not saying diesel isn't cool... It is. However, the only diesels I like are the old diesels (i.e. 4BT, 6BT, etc.) where they were much, much simpler, easier to work on, and no overrun with electronics and sensors like all the modern diesels.

In my area diesel is also usually either the same price or more expensive than standard gasoline.

I just don't really see an advantage to running diesel over gasoline, unless you like the "cool" factor.

There are areas where diesel fuel might be cheaper than gasoline, but I think it's negligible at best. Besides, you'd pay over 10k for this swap, and how long would it take you to offset that money in relation to the amount of money you'd save on your more fuel efficient engine?

Sorry, but the math simply doesn't add up.

I think this Cummins swap is cool, but it's nothing I'd consider. Still, I look forward to seeing others do it.

A well known member of WF undergoing the swap has done the math and it would take 10-15 years of driving for the math to even out.

 

[JamesAndTheSahara]

Did read an article that sad there was an adapter for the R2.8 to the AX15 and NV3550. If I could swap out motor only with a little wiring it may not be too costly of a swap.

Yes its like $1500.00.

 

[Chris]

What diesel was swapped into the vehicle? Was it the engine noise or exhaust that was mind numing? I just can’t imagine a 4 cylinder diesel being that loud.

It was a 4BT from an older box truck. The newer diesels (like this one) are more quiet, but those older ones are insanely loud.

A well known member of WF undergoing the swap has done the math and it would take 10-15 years of driving for the math to even out.

Yep, that sounds about right. So the only point I am trying to get at there, is that if you're doing the swap to save money at the pump, it's not worth it unless you can wait 10-15 years for your ROI.

 

[JamesAndTheSahara]

It was a 4BT from an older box truck. The newer diesels (like this one) are more quiet, but those older ones are insanely loud.



Yep, that sounds about right. So the only point I am trying to get at there, is that if you're doing the swap to save money at the pump, it's not worth it unless you can wait 10-15 years for your ROI.

My main concern is not necessarily a ROI in terms of gas but I know my 4.0 will not last forever. What kind of life could I expect out of a newer diesel like the 2.8?

The whole issue with the new diesels is making them 50 state emission compliant, they have to have all the computer stuff. Its the world we live in and will need to adapt eventually. Why not learn it and get ahead of the curve? The EPA isn’t going anywhere longterm.

 

[Chris]

My main concern is not necessarily a ROI in terms of gas but I know my 4.0 will not last forever. What kind of life could I expect out of a newer diesel like the 2.8?

The whole issue with the new diesels is making them 50 state emission compliant, they have to have all the computer stuff. Its the world we live in and will need to adapt eventually. Why not learn it and get ahead of the curve? The EPA isn’t going anywhere longterm.

That's my issue with the new diesels. Get one of those old 4BT diesels like they use in older box trucks, and that thing will run until the end of the world. Hardly any electronics at all (less than the 4.0), and built like a tank (also very heavy).

The new diesels have crap tons of emissions on them and electronics galore. My buddy is a veteran diesel mechanic, and he always goes on-and-on about how much he hates the new diesel engines in terms of reliability and maintenance (ease of working on them). They've gotten to be the same as a modern gasoline engine. Sure, they're more efficient than the older diesels, but with that comes a slew of electronics, sensors, and tons of other junk.

So it's a toss up... Do you want something simple to work on, built like a tank, and very stout? If so, I'd probably say stick with your 4.0 or just get an older 4BT diesel.

However, if you don't mind the complexities that come with a newer diesel, then go for it. If the 4.0 can last engine 600k plus miles without touching the internals, I suspect the same can be said for any modern engine.

Engines have gotten to the point where you don't need to worry about internals for a long, long, long time. That's never what fails, it's always electronics, sensors, cooling systems, or seals, pretty much every time.

 

[JamesAndTheSahara]

That's my issue with the new diesels. Get one of those old 4BT diesels like they use in older box trucks, and that thing will run until the end of the world. Hardly any electronics at all (less than the 4.0), and built like a tank (also very heavy).

The new diesels have crap tons of emissions on them and electronics galore. My buddy is a veteran diesel mechanic, and he always goes on-and-on about how much he hates the new diesel engines in terms of reliability and maintenance (ease of working on them). They've gotten to be the same as a modern gasoline engine. Sure, they're more efficient than the older diesels, but with that comes a slew of electronics, sensors, and tons of other junk.

So it's a toss up... Do you want something simple to work on, built like a tank, and very stout? If so, I'd probably say stick with your 4.0 or just get an older 4BT diesel.

However, if you don't mind the complexities that come with a newer diesel, then go for it. If the 4.0 can last engine 600k plus miles without touching the internals, I suspect the same can be said for any modern engine.

Engines have gotten to the point where you don't need to worry about internals for a long, long, long time. That's never what fails, it's always electronics, sensors, cooling systems, or seals, pretty much every time.

To keep my Jeep on the road as a long term DD I want to make sure whatever I do to it will be 50 state emission legal. This eliminates the older diesels, in the future IMO they won’t be an option for a DD for me at least.

Would you still argue the longevity of the 4.0 remains the same with your supercharger running low boost?

I don’t have an official number that represents what kind of fuel economy I can expect out of my TJ. I will however be providing several numbers to record how drastically some things affect fuel economy after bringing her to her former glory (IE proper gearing, speedo gear, ect).

 

[Chris]

To keep my Jeep on the road as a long term DD I want to make sure whatever I do to it will be 50 state emission legal. This eliminates the older diesels, in the future IMO they won’t be an option for a DD for me at least.

Would you still argue the longevity of the 4.0 remains the same with your supercharger running low boost?

I don’t have an official number that represents what kind of fuel economy I can expect out of my TJ. I will however be providing several numbers to record how drastically some things affect fuel economy after bringing her to her former glory (IE proper gearing, speedo gear, ect).

With the supercharger, only time will be able to tell. However, mines been problem free for years now. I honestly don’t think that there is an issue with reliability and a supercharger, as long as you run low boost. With the amount of power I gained on my 4.0 with only 6 psi, there’s no way I’ll ever need to swap a bigger engine in now. All that for $2500 too!

IMHO, a supercharger is a great solution. Gobs of power, easy to bolt on, and a low cost compared to engine swaps. It really is a huge difference, night and day. It’s almost like I have two 4.0s under the hood now.

 

[JamesAndTheSahara]

With the supercharger, only time will be able to tell. However, mines been problem free for years now. I honestly don’t think that there is an issue with reliability and a supercharger, as long as you run low boost. With the amount of power I gained on my 4.0 with only 6 psi, there’s no way I’ll ever need to swap a bigger engine in now. All that for $2500 too!

IMHO, a supercharger is a great solution. Gobs of power, easy to bolt on, and a low cost compared to engine swaps. It really is a huge difference, night and day. It’s almost like I have two 4.0s under the hood now.

Any mpg increase or did it decrease with the performance mod? Again, i’m biased this is still my number one choice alongside a full refresh of the 4.0.