Cummins Repower ISF 2.8 for Defenders

donb

Well-known member
From anyone that has experience with this engine. Will this engine allow a fully loaded Defender to cruise effortlessly at 70-75mph on windy interstates? I imagine the answer is yes. This is my biggest pain point with my truck right now. I hate having to watch EGT's etc trying to motor on the highway.

A couple months ago I rented a diesel MB sprinter van. With 10 guys inside + luggage we were able to effortlessly cruise at 85+mph from SLC to Moab and back.

Here is a quote I found from some Jeep testers...



http://www.fourwheeler.com/features/1710-beta-testing-the-r2-8-diesel-with-cummins/


There were 3 R2.8 Cummins powered vehicles on UA this year (one being a RRC). They all had at least 37? tires and the vehicles have to be able to travel 75 mph on the road and still be able to 4 wheel all day for a week or so. I know Cummins was one of the sponsors so maybe that is why there were 3 trucks with the R2.8 but then again I?m sure they wouldn?t run it if it didn?t work well.

There are some great vids on IG of the Cummins in action. One I loved was of Fred Williams Tube Sock trying to get over a 5-6 foot obstacle. After a few tries with the skinny pedal and no success he just picked his low gear and crept right up at idle. I saw pictures of the trucks on top of Mt Washington, NH so that must have been a good on road test of the R2.8.

Maybe try DMing Fred Williams, Dirt Head Dave, Verne Simons and Christian Hazel with some specific questions on the engine?

The increased warranty is a nice addition. I think I said it before but feel if Cummins want to get even more buyers a purchase program would be nice. I did it with Ransomes/Bobcat for a mower years ago and it made the purchase of a nicer machine a lot easier.


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rocky

NAS-ROW Addict
Driving up Mt Washington is a breeze.
Its under half the height of Pikes Peak. I've never yet managed to be in Colorado springs on a good enough day to do that drive.
 

donb

Well-known member
Driving up Mt Washington is a breeze.
Its under half the height of Pikes Peak. I've never yet managed to be in Colorado springs on a good enough day to do that drive.


Actually never drove it but hiking up and skiing some runs then riding and hiking down Tucks was pretty tough. I?ve driven up Mt Mansfield a bunch and figured the drive up Mt Washington would be more difficult.

My main point was since Adam is on the east coast and in Long Island that the UA guys 4 wheeling in New England then driving up Mt Washington with gear filled vehicles was a decent test. I?m not 100% certain how their rigs did but the IG feeds didn?t say anything bad about the R2.8?s on the trip.


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rocky

NAS-ROW Addict
Hiked Washington as well. On the day they did the auto race. Those guys are insane!

Mt Mansfield in VT is technically more challenging to drive and on the car. I did that in wife's Volvo. Paddle shifters are great except on those hair pin turns when the steering wheel is upside down. And you forget.....
 

donb

Well-known member
Hiked Washington as well. On the day they did the auto race. Those guys are insane!

Mt Mansfield in VT is technically more challenging to drive and on the car. I did that in wife's Volvo. Paddle shifters are great except on those hair pin turns when the steering wheel is upside down. And you forget.....



I just figured everything at Mt Washington was burlier than any other mtn in NE so the drive up would be as well. Auto racing up it must have been sweet to see!

Some of the folks at Rovers North did the Mt Mansfield auto road during the winter which must have been crazy! Even on a nice day it gets spooky with the drops and narrow dirt road.

Maybe if someone at RN gets ahold of an R2.8 they could test it thru the Notch and then Mt Mansfield? [emoji6]


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AdamSanta85

Well-known member
Were you worried at all about EGTs on that?

Nope

1. Rental
2. No EGT gauge
3. It did it with 10% throttle, running cool and calm the whole way, getting high 20's mpg, speed limit was 80mph. We weren't beating on it at all. I kept saying "Why the hell can't my 200 drive like this thing?". My hope is that the R2.8 would make my truck perform like my buddies Colorado ZR2, although the ZR2 has 100ft lbs more torque but weighs 1000lbs more.
 

Uncle Douglas

Well-known member
Callsign: delete
Computer controlled diesels monitor/control their own EGT's. Modern diesels also use much higher fuel pressures than our antique rotary pumps make.
 

WreckITFrank

Technical Excellence Contributor
Nope

1. Rental
2. No EGT gauge
3. It did it with 10% throttle, running cool and calm the whole way, getting high 20's mpg, speed limit was 80mph. We weren't beating on it at all. I kept saying "Why the hell can't my 200 drive like this thing?". My hope is that the R2.8 would make my truck perform like my buddies Colorado ZR2, although the ZR2 has 100ft lbs more torque but weighs 1000lbs more.

I have to say my 3.0l CRD FIAT (Jeep Grand Cherokee) runs like a dream. 25-32MPG depending on conditions, quiet, plenty of torque. If I could have had equivalent in LR3/4, my LR3 it would still be in my driveway.
 

AdamSanta85

Well-known member
Computer controlled diesels monitor/control their own EGT's. Modern diesels also use much higher fuel pressures than our antique rotary pumps make.

Thanks Doug. I assume you have drive the R2.8 truck on the highway. Will it cruise at 70-75 without having to think about it?
 

vintagepatina

Well-known member
santa, your 200 should as well you just need to have it geared right and wind it out. most are way under geared. put in a 1.2 case and put your foot in it.
 

AdamSanta85

Well-known member
santa, your 200 should as well you just need to have it geared right and wind it out. most are way under geared. put in a 1.2 case and put your foot in it.

If anything my truck is over geared now. Now that I have 33's, taller 5th in my R380, rack, bumper yadda yadda with boards on the roof on a windy day if I lay into it in 5th at 65mph I will hit 1250egt before I get to 75. Cruising RPM at 65mph is like 2300?... back off throttle, back into it.. I mean its fine, it works, but I would rather not have to do that. It will cruise at 65-70 fine, I just wish it had more power on highway, didn't have to monitor EGT, and wasn't so affected by a headwind. I imagine the R2.8 could accomplish this.
 

rocky

NAS-ROW Addict
You'd go from
111hp@4250 to 167@ and torque from 195ftlbs@1800 to
161hp@3600 and 267ftlbs @1500-3000rpm

75mph is what 2600rpm? I'm guessing you wouldn't have to lay into it as much with a over a third more torque and still being inside the max torque band. There's precious little out there about EGTs with these engines.
 

vintagepatina

Well-known member
im not sure what you're expecting. 5th gear is a cruising gear not a "lay into it" gear. let alone with boards and such on the rack. maybe its the "loose nut behind the wheel" as the old timers would say.
 

vintagepatina

Well-known member
if what you're expecting is to be able to put it in 5th and just leave it there on the highway you are going to need a few things, namely about 400 + ft lbs and a pile of spare transmissions after destroying 5th in all of them.
 

AdamSanta85

Well-known member
im not sure what you're expecting. 5th gear is a cruising gear not a "lay into it" gear. let alone with boards and such on the rack. maybe its the "loose nut behind the wheel" as the old timers would say.

if what you're expecting is to be able to put it in 5th and just leave it there on the highway you are going to need a few things, namely about 400 + ft lbs and a pile of spare transmissions after destroying 5th in all of them.

Thanks for the driving lessons dad. Have fun doing 75mph in 4th gear.

I am looking to hear from people with experience with the R2.8, not about how my 200 should make me happy because I am driving it wrong.
 

vintagepatina

Well-known member
please, if you are asking for opinion i am offering one. if you want to just leave it in 5th from 65mph without ever having to downshift, you don't know how to drive a manual transmission. 5th gear never meant for full load. regardless of engine or transmission.
 

Napalm00

Technical Excellence Contributor
I see you are still talking out of your ass.

"5th gear is never meant for full load" lol get off the internet
 
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