Cummins 2.8L inline 4 diesel

Dalko43

Explorer
I'm sure some here have heard of Cummins' forthcoming release of its 2.8L inline 4 repower engine; it's being marketed as a crate engine that would be suitable for engine swaps into smaller vehicles. I'm excited to see this thing come to market and, as I understand it, it is basically a smaller version of the 3.8L inline 4 that Cummins sells worldwide.

I do have a question though: Why is the torque only rated at 267lb-ft? Not that I think that 267lb-ft isn't enough, because it probably is plenty for the type of applications this engine will be used for. But the Duramax 2.8L inline 4 is rated at 370lb-ft. The horsepower between the two (160hp for the Cummins and 180hp for the Duramax) seems similar. Why is there such a big discrepancy between the torque figures? Does anyone think it would be possible to tune the Cummins to higher torque with aftermarket parts and tunes?
 

Pokey

Adventurer
So much for 1st quarter 2017---Cummins just forwarded a delay on this now. Claims of needing to still do "testing" etc. Claiming the next announcement will be Mid April/ Easter. So even if they announce pricing and a future delivery date, they are shooting to miss a large segment of people interested in doing this swap pre-summer.

I imagine the " testing" is all b.s. since this engine has been running in the Fotons for years.......and they are simply waiting for the Trump/ Import duty clarity. I cant imagine they would be happy to price it at $10k and then 6mo. later find out that Trump will be enforcing a re-pricing to $12k which will - piss customers off....and price many out of the market.

If Cummins has done their market research- they will want it priced spot on where they know their potential customer base will reach their expected/projected sales goals. So it really behooves them to wait for import duty clarity. At this rate- the option may not materialize until fall or 2018 given Washington D.C. disfunctionality
 

Pokey

Adventurer
also- Cummins makes those figures very conservatively as they rate them for a much longer service life than a duramax. The computer is easily flashable for more power and that 2.8 has put put well over 200hp and 350tq with simple reflash. For a sub 4000lb rig....you could leave it alone and be very happy with 160hp 270tq. with proper gearing. Once you get to 4500lbs and big tires/ poorly geared- you will need a very mild 20hp and 30tq bump.

Any more rig weight than 4800lbs than this and you should really be holding off for the r2.8's bigger brother the 3.8 which jumps into the 200hp-400tq + range destressed......vs stressing out a little 2.8.
 
Cummins 2.8L Diesel "Repower" engine kit

There is already a thread on this but I apparently can't figure out how to add the link to it.
 

Dalko43

Explorer
also- Cummins makes those figures very conservatively as they rate them for a much longer service life than a duramax. The computer is easily flashable for more power and that 2.8 has put put well over 200hp and 350tq with simple reflash. For a sub 4000lb rig....you could leave it alone and be very happy with 160hp 270tq. with proper gearing. Once you get to 4500lbs and big tires/ poorly geared- you will need a very mild 20hp and 30tq bump.

Any more rig weight than 4800lbs than this and you should really be holding off for the r2.8's bigger brother the 3.8 which jumps into the 200hp-400tq + range destressed......vs stressing out a little 2.8.
Where have you seen a 2.8L cummins put out those kinds of figures?

And so you're saying that the reason for the torque discrepancy is simply due to engine longevity ratings?
 

eggman918

Adventurer
Where have you seen a 2.8L cummins put out those kinds of figures?

And so you're saying that the reason for the torque discrepancy is simply due to engine longevity ratings?
This is a bit apples to oranges but with the mechanical 4BT they came from Cummins in factory tunes from 105HP non intercooled turbo configuration to the 250HP marine configuration this was done without and real change to the engines internal parts other that maybe a different camshaft grind and piston bowl design the rest was injection pump/injectors and turbo and intercooler/aftercooler. But with more power came a shorter life between overhauls,but even if you build to 250HP if you don't "flog" it and run at those power levels all the time they will still last a reasonable length of time.......$.02
 

Pokey

Adventurer
what kills diesels if you watch egts and dont flog it......is daily driving use. Diesels are only truly advantageous in constant/long haul scenarios. ie....one cold start and put 1500-2000mi down......vs daily driver/grocery getter where 2000mil means 800cold starts/ 90% more wear. When you use them as daily drivers diesels end up costing more up front- more to operate/ and more to upkeep/ and dont have the added longevity over gas in that scenario. Modern small liter diesels are better balanced and dont suffer as greatly from startup/cold operation wear.....but they also are a touch more stressed as far as output.

yes diesels can do more work/ haul heavier loads liter/per liter and use less fuel.......but as a daily driver you pay additional maintenance/upkeep and wear/longevity costs to make that happen.

Keep it parked and use it to haul cows 500mi to market or a trialer 700mi to scoup stuff up when needed.......and it will last 500k-600k+ miles with very low relative costs. (if its a well designed timeless diesel/ toyota/isuzu/cummins)

imho u just need to accurately assess how you plan to use it and tradeoffs/choices associated with it.
 

Dalko43

Explorer
This is a bit apples to oranges but with the mechanical 4BT they came from Cummins in factory tunes from 105HP non intercooled turbo configuration to the 250HP marine configuration this was done without and real change to the engines internal parts other that maybe a different camshaft grind and piston bowl design the rest was injection pump/injectors and turbo and intercooler/aftercooler. But with more power came a shorter life between overhauls,but even if you build to 250HP if you don't "flog" it and run at those power levels all the time they will still last a reasonable length of time.......$.02
So basically with some tunes, it probably would be a 330-360lb-ft engine?

This 2.8L Cummins comes with a front mounted intercooler, right?
 

calicamper

Expedition Leader
Given a repower for 18hpin my boat is about $9000 for the engine. I think 10k for a 2.8L is a tad low. Mercruiser has sold them for yrs in marine repower options they are no where near $10,000.
Just sayin...
 

RoyJ

Adventurer
Where have you seen a 2.8L cummins put out those kinds of figures?

And so you're saying that the reason for the torque discrepancy is simply due to engine longevity ratings?
If I had to guess, probably in marine applications.

But numbers aren't too hard to guess - modern diesels, from the same manufacturer, of the same configuration (inline), of equal valves per cylinder, makes very similar tq per displacement.

The volumetric efficiency, intercooler efficiency, will be very similar. And engines ingesting the same amount of air at similar temperatures will make similar power.

So, if they could make an inline 6.7 make 900 lb-ft with decent longevity, a 2.8 should easily make 350.
 

Dalko43

Explorer
If I had to guess, probably in marine applications.

But numbers aren't too hard to guess - modern diesels, from the same manufacturer, of the same configuration (inline), of equal valves per cylinder, makes very similar tq per displacement.

The volumetric efficiency, intercooler efficiency, will be very similar. And engines ingesting the same amount of air at similar temperatures will make similar power.

So, if they could make an inline 6.7 make 900 lb-ft with decent longevity, a 2.8 should easily make 350.
As I understand it, this particular inline 4 is produced (and partly designed?) in collaboration with a Chinese company. So this thing definitely isn't the same as a 4bt in that Cummins didn't simply lop off two of the cylinders from the bigger inline 6. There was actually an interesting video that Dirt Every Day did, where they compared it to a Chevy V8 crate engine and an old school Jeep inline 6 4.0L...the Cummins obviously got much better mpg than the other two engines, though they did break open the Cummins' oil pan, which is made of a composite material (I think that's kind of cheap on Cummins' part and I hope its not indicative of the engine's overall quality).


I have high hopes for this engine, and even if 267lb-ft is the limit, I could see Jeep and Toyota owners jumping all over this for engine swaps.
 

RoyJ

Adventurer
As I understand it, this particular inline 4 is produced (and partly designed?) in collaboration with a Chinese company. So this thing definitely isn't the same as a 4bt in that Cummins didn't simply lop off two of the cylinders from the bigger inline 6.
Oh don't get me wrong, I didn't imply the 2.8 is related to a current Cummins series. I'm just saying based on current generation Cummins technology, it's illogical to think 267 lb-ft is the "hard limit" for a 2.8L tubo diesel. We're talking the same torque as a naturally aspirated V6 Camry!

I've seen that video, fairly impressive. People commented the mpg may get even better as the engine gets broken it. Just hope Cummins don't price themselves out of competition...
 

bfdiesel

Explorer
With the numbers the 2.8 duramax can lay down, this engine is capable of more than advertised. Just needs someone to crack the computer.
 
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