Cummins R2.8

[06 H3]

The past 2 years I have been following the Cummins R2.8 at UA. Fred Williams has one in Tubesock, the UA build vehicle has one, and a few other rigs do. Why hasn’t anyone considered this as a swap? The ease of it alone sound so appealing.

The price is 9k but that gets you EVERYTHING. You can start the motor in a crate after you grab a bucket of fuel.

After that you get an adapter for the trans and your ready to rock. It’s legal in 49 states (I think CA is the exception)

Mileage is great, they seem to never ever overheat and ran the coolest in AZ last year when it was 125 out. Power wise they seem to be detuned from the factory but that makes sense to stay emissions compliant since they are legal swaps. In talking with others then can make more power and stay reliable to boot.

Lastly, If your H3 is paid off, so you have room for a monthly payment and you don’t wanna fork over 9k cash, there is financing available. No other engine swap would offer that!!

Just some food for thought...

 

[gfbh3t]

I have considered it. After seeing it in person do you think the H3T is to heavy?

 

[jphh20]

I have also considered it as well. I have been trying to see if the torque will get our rigs up and moving. The numbers out of the box seemed unappealing and I thought a SAS or the outfitter IFS with a re-gear would be a more reasonable approach.

If the wick can be turned up, you have perked my interest. Just need the I5 to grenade to consider if it will fit and what secondary adaptations need to be considered.


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[06 H3]

My co driver actually asked him about heavier vehicles. He said they have overlanding guys in land cruisers that are pushing 9k with a trailer. They aren’t fast but they keep pulling. With the I5 in hills, I remember it would accelerate in 3rd then shift to 4th then couldn’t hold 4th, it was a constant battle to keep it happy. With talking to him and others running the 2.8 it seems the thing can hold any gear.

They have a frontier with a 2.8 and towed a heavy grand wagoneer in the hills and it had no issues power wise, the brakes and suspension were the limiting factor.

Basically it’s not going to outrun a car but it will hold any speed in the gear it’s in. A guy with a heavy JK said if he sets cruise at 70 it will hold 70 no matter the hill, headwind, etc. they just chug along.

 

[Vdawg1115]

I think it’s winning. I don’t have to drive super fast down the highway. Would prefer to sip fuel and not downshift

 

[alrock]

Talk to Dwaine (PCF) as he's pretty much an expert when it comes to Cummins and he's learned a bit about our H3s since we refuse to leave him alone

 

[mdocod]

Can't really compare the "peaky" naturally aspirated HP figures of our i5's to this type of diesel engines HP figures. They have different "usability" especially when paired with less than ideal drivelines. Once the turbo is spooled this type of engine regulates its own atmosphere, so they tend to have flat torque followed by flat power curves, which in practice translates to good power all over the place, and minimal power loss in the mountains from thin air (5-15% instead of 20-40%). Up in the mountains, RPM for RPM, the diesel will outperform the i5 all the way up through the RPM range available on the diesel (4200). However, if we let the 3.7L scream up there in the 4500-6000RPM range it should be able to match or best the 2.8R for power.

The 3.7L Atlas i5 @ 65MPH pushing 4th gear 4L60E on 35" tires will be churning about 2000RPM (converter locked), making up to about 140lb/ft of torque at the crank up in the mountains, or around 55HP.

The 2.8R Cummins @ 65MPH pushing 4th gear 4L60E on 35" tires will be churning about 2000RPM (converter locked), making up to about 230lb/ft of torque at the crank up in the mountains, or almost 90HP.


So... from the perspective of trying to keep from hunting in and out of top gear, and trying to keep the converter locked in 4th for maximize driveline efficiency (less heat, less loss, better MPG), the diesel would be a better match to this driveline, especially in the mountains where the advantage could easily average as much as ~65% power advantage at equal low RPMs. If we remove the equal RPM criteria, and drop down to 3rd gear on the 3.7L, it will roughly match the 2.8R for power in 4th gear. Drop down to 2nd gear on the 3.7L and it will roughly match the 2.8R for power in 3rd gear. This creates a bit of a conundrum. The 2.8R is a better option as far as preventing downshifts, but once downshifting is on the table, there isn't much advantage as the 3.7L can match the 2.8R for power if it has a 1 gear advantage.

 

[08H3]

I've definitely considered it. I wish I was as capable as most of you guys with a wrench, but I know my limits. If I'm going to invest $9000 in an engine for a $5000 truck I want to find someone that's going to install it correctly. Finding a capable local shop is the problem for me. I'm approaching 250,000 miles, and starting to use oil, so I probably need to start putting more time into finding some options.

 

[CaseyS]

08h3. If you are using oil the clock is ticking. I made mine last until 259k.

For what its worth, the 4bt at those same 2000 rpm figures above can give 320+ ft-lbs for a basic engine and 400+ for an intercooled setup and a tune that can be done with a screwdriver and a 10mm wrench.

The power figures for the 2.8 are underwhelming. I'm sure it has more potential, but haven't seen any tunes around for it yet.

 

[06 H3]

08h3. If you are using oil the clock is ticking. I made mine last until 259k.

For what its worth, the 4bt at those same 2000 rpm figures above can give 320+ ft-lbs for a basic engine and 400+ for an intercooled setup and a tune that can be done with a screwdriver and a 10mm wrench.

The power figures for the 2.8 are underwhelming. I'm sure it has more potential, but haven't seen any tunes around for it yet.

Yep, the 2.8 is bought directly from Cummins. They will be conservative for emissions and longevity purposes.

I know they did a tune at the beginning of the week that bumped them over 310 ft lbs. that was a Cummins tune so I’m sure it’s still very conservative since they are the manufacturer. The rigs I was with have done a lot of the beta testing with Cummins.

 

[Portager]

I'd suggest you consider at the 4 cylinder Duramax 2.8l as an alternative to the Cummins 2.8. The Duramax 2.8l has been sold internationally since 2011 and it has a good track record. GM made significant improvements for the US market (mainly Colorado and Canyon) including full US emissions compliance, improved gear-driven oil pump, and balance shaft, increased operating temperature range and reduced noise level. Also, the Duramax 2.8 is offered with an exhaust brake on the Colorado and Canyon (I feature that I love on my Duramax Sierra).

Although the Duramax 2.8 has lower horsepower than the Alpha 5.3l (181 hp vs 305 hp) it has slightly higher torque (369 ft-lbs vs 335 ft-lbs) and a flater torque curve. The weight is the same at 520 and only 17 lbs heavier than the Cumming 2.8l.

Finally, the Duramax could be easier to integrate into the Hummer because you could borrow electronics from the Colorado and/or Canyon as necessary. Look for a wrecked 2017+ diesel Colorado or Canyon with a good engine and ...

 

[CaseyS]

Electronics and easy to integrate into a hummer don't belong in the same sentence. The ecu used in the i5s has very little support.

 

[Portager]

I that thinking you could take the ECU etc. out of the Colorado/Canyon and throw the ECS for the i5 away. Basically, the Hummer would think it was a diesel Colorado/Canyon electronically, but you'd still have to adapt to the Hummer switches etc.

 

[atvspeed4]

There was a rare H3 offered in global market with the diesel 4 cylinder. Wonder how much overlap there is with that diesel and the one in the new Colorado. If there is, that ecu would be able to communicate with the h3 bcm

 

[MilamJR]

Just got an email from Cummins and the 2.8 is $500 off until July 31.


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[PreferredChassisFab]

Preferred Chassis Fabrication Inc. finalized its certification to be a dealer for the Cummins R2.8 Builder/Installer program!
This allows PCF to install the Cummins R2.8 in the Scorpion as well as performing installations and repowers on customer vehicles.
The R2.8 is a new design, small, light diesel engine package that pushes 161 hp @ 3600 rpm and 267 lb-ft at 1500-3000 rpm and only weighs 503 lbs!
Contact PCF if you have interest in a R2.8 for your vehicle.

 

[LagunaH1]

If the 5.2 V8 in my Jeep ever dies, I'll be pretty interested in the 2.8 Cummins. Did I hear correctly that it is NOT emissions legal in California?

 

[PreferredChassisFab]

If the 5.2 V8 in my Jeep ever dies, I'll be pretty interested in the 2.8 Cummins. Did I hear correctly that it is NOT emissions legal in California?

Cummins is working on several major revamps to the R2.8 program, mainly being the warranty and emissions compliance. Should have updates soon.

 

[06 H3]

I know they changed up some tuning and tried them out on the 3 R2.8 Cummins rigs on UA and they were all pleased.

 

[MilamJR]

Cummins Repower[emoji769] is proud to offer the R2.8 Turbo Diesel now with 310 LB-FT of torque and a 2-year warranty. In celebration of 310 LB-FT of torque, save $310 off MSRP on a new R2.8 purchased through October 5, 2018 with discount code TORQUE at checkout.

For more information, please visit cumminsrepower.com


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[lsv_palana]

Hello dear friends !Maybe I dont speak English so good, but i read all the thread, search cummins site but did not found answer: can cumminis offer ready solution to repower hummer h3 with disel engine ? i mean TOTALY ready kit including all needed harness, hardware etc ... thank you for clear answer.

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[woodwardsh3]

Hello dear friends !Maybe I dont speak English so good, but i read all the thread, search cummins site but did not found answer: can cumminis offer ready solution to repower hummer h3 with disel engine ? i mean TOTALY ready kit including all needed harness, hardware etc ... thank you for clear answer.

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No i belive it is a crate motor and you need a adapter plate for transmission

 

[fanugy]

I picked up a T and have kicked around an LS3- but I have a crate LS2 vette motor with a hot cam in my H3 and want to do something different (this is a GREAT ride but I don’t think I will do much with it off-road). That said, the specs on the Repower page for the 6l80 gear ratios with 4.56 on 37’s look very appealing. I want to build a desert duck hunting rig for some of the reservation pond jumping- nasty sharp rocks and very loamy mud...

What did you 6l80 guys end up doing to marry the transfer case?


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[SolidusJ]

I would do this just to have a sticker on my back window that says, "I rather be cummin than stroking." Lol

 

[amrg]

Im assuming a 6l80e on a stock H3 t-case in an H3
From a mechanical standpoint, you will need an adapter to bolt the case to the trans and clock it at the proper orientation for the dshaft to clear. You will also need a custom output shaft from a turned down/resplined 6l80e output shaft to switch from 32 splines to 29 to match the tcase input (moser)