Engine Swap: Cummins R2.8

[Digger556]

Now that I have the ball rolling, I thought I would start a thread to document my latest upgrade.


A little background:
I purchased my Bronco in June of 2013. It was drive-able and had some nice parts, but I had a whole list of planned upgrades. It didn't take too long to strip about everything out of the truck and replace it. Drivetrain, suspension, axles, cage, interior, etc. (There's a link in my sig. if you want to see the whole build.)

One thing that stuck throughout was the 351W the previous owner installed. It was healthy, but built like a drag engine. Lots of high RPM horsepower. It was fun to rip around in, but wasn't very drive-able and got around 9-10 mpg. I made some serious effort to modify it to my needs. The long term plan was to have something as drive-able as a newer vehicle. I swapped cams, headers, added EFI (megasquirt) and a bunch of misc things I can no longer remember. I made good progress. The Bronco was up to 14 mpg, a 40-50% improvement and the plugs were coming out a nice tan color. I was still fighting a couple of small issues and last June I decided to swap out the intake. Long story short, Edelbrook took 5 months to ship my manifold. I won't go into details, but by the time it showed up, I was so disgusted at the situation, I took stock of where I was and decided to change directions.


THE PLAN:
I looked at the Cummins R2.8 prior, but it was a little light on torque and compared to the 351W, looked downright whimpy. While attending SEMA this year, I stopped at Cummins' booth and eyeballed the R2.8 again. I always had a long term plan to go diesel, but thought a 4BT would be my only option. As it happens, Cummins just released a new tune for the R2.8 that pushed torque to 310 lbft (HP is still 161). When I returned home, I started crunching numbers and talking with another member that daily drives a 4BT.

Living in Colorado, one thing I hadn't given enough thought towards was how much power and torque the 351W was losing at altitude. Once I combined all these factors, the little R2.8 was starting to look feasible. I created an R.O.I before even talking to my wife. (She's been great about letting me spend money on the Bronco, but this was a big chunk of change.) Even with conservative numbers, the R.O.I. looked so good we decided it would almost be ridiculous to continue with the 351W.

So in early December I placed my order. It took about a week for the engine to show up:

 

[Digger556]

The engine came with just about everything.

I still needed to design and build a transmission adapter, buy a CAC and a whole lot of plumbing. For those unfamilar, the R2.8 comes with engine, computer, wiring harness, remote filters, gas pedal, engine telemetry gauge, accessory drive including PS pump, 120amp alternator, vacuum pump, and a nice install manual.



I've spent the last month reading, taking notes and planning. Finally this weekend I pulled the 351W.

A friend came over to help with the pull.

 

[Digger556]

Here's a little comparison of the 351W vs the R2.8

The 2.8 is a little taller from crank centerline, but doesn't hang down as far. It's about 1.5" shorter than the V8 as configured, but slightly wider in some critical areas with all the accessories hanging off the block.


So that's where I'm at. Now I have to get going on the transmission adapter. (I want to continue using my ZF5/AtlasII combination.) I'll post updates as I make progress.

 

[hyghlndr]

Thanks for sharing, looking forward to the progress reports.

Are there adapters available for any of the more frequent swap Bronco transmissions?

 

[toddz69]

Very cool! Looking forward to following along with this.

Todd Z.

 

[EB70]

I'm passionately watching this. I have thought about the same thing. I know (and I know you know) about mating it to an AX-15 etc.

Please keep us updated. I am really interested in seeing how this turns out.

 

[markw]

Me too! Excellent pics and thank you for pulling the trigger on this.

 

[ntsqd]

sub'd

Interesting that the total volume of the 2.8L looks to be bigger than the total volume of the 5.8L. Lots of 'stuff' I'm sure. Love our 12v, will be interesting to see how this plays out.

 

[Dbteak]

I've been waiting for someone to do a build with the new Cummins. Give us lots of pictures.

 

[okie4570]

Cool stuff, keep a tab on final cost, if you dare and let us lol. Looking forward to following along

 

[Digger556]

Thanks for sharing, looking forward to the progress reports.

Are there adapters available for any of the more frequent swap Bronco transmissions?

Not at this time, which is my biggest headache. Axis Industries makes adapters for the AX-15, NV3550, and LS-based transmissions, but nothing native to a Ford.

sub'd
Interesting that the total volume of the 2.8L looks to be bigger than the total volume of the 5.8L. Lots of 'stuff' I'm sure.

Agreed. It's a little deceptive because the 5.8 is missing its intake, headers, ignition etc. Also the 2.8 is sitting up higher on the pallet and you don't notice how far down the oil pan hangs on the 5.8. All-in-all they are not too different in size.

 

[Timmy390]

Not at this time, which is my biggest headache. Axis Industries makes adapters for the AX-15, NV3550, and LS-based transmissions, but nothing native to a Ford.

What trans are you planning to run?

Been looking at diesel swaps too but in my Samurai.....lol

Tim

 

[Broncobowsher]

I got to drive a 2.8 a few years back. It was a Cummins build backed with a ZF 8-speed auto. It was pretty sweet. Way more refined then the 4BT (I have one ridden in one of those).

I am thinking a little about your transmission. You have the gas version of the ZF, there is a diesel version that has a closer ratio spacing. That might be a better match. All of the 2.8 manual transmissions are fairly close ratio. Even one that you didn't mention (because it was a custom build by Cummins and they don't offer it, but I hear it drives REAL nice, Nissan Frontier 6-speed manual). I really want that adaptor for myself.

Anyway, you might want to take a second look at your transmission choice. Look at the diesel version of the ZF. Of course that would mean different adaptors then the small block ZF.

Am I correct in the 2.8 is an SAE #3 bellhousing? I thought that is what they are running. Not a Cummings pattern, but the SAE interchange standard. Better suited for industrial applications, but at least it is a standard.

 

[Digger556]

What trans are you planning to run?

Been looking at diesel swaps too but in my Samurai.....lol

Tim

ZF5 / AtlasII combo

I am thinking a little about your transmission. You have the gas version of the ZF, there is a diesel version that has a closer ratio spacing. That might be a better match. All of the 2.8 manual transmissions are fairly close ratio.

Anyway, you might want to take a second look at your transmission choice. Look at the diesel version of the ZF. Of course that would mean different adaptors then the small block ZF.

Am I correct in the 2.8 is an SAE #3 bellhousing? I thought that is what they are running. Not a Cummings pattern, but the SAE interchange standard. Better suited for industrial applications, but at least it is a standard.

The 2.8 is not an SAE bellhousing, which is presenting an issue to many would-be installers. There are tons of SAE bellhousing adapters out. My choice to go with the ZF5 was in-part based on the possibility of going 4BT and not needing to switch transmissions due to factory available adapters.

Closer ratio spacing has an advantage for daily driving and towing. I know the wide-ratio version of the ZF is the most common and was even used in diesel applications. Additionally there are members already running a 4BT/ZF5 combination with success (including DD'ing and towing). The 2.8 has a wider RPM band than a 4BT or 7.3 PowerStroke, so I haven't been too concerned about.

One thing I haven't nailed down is what the actual redline of the R2.8 is. The Cummins customer service guy said "he thought" it was 3600rpm, but he wasn't sure. He also gave me the dyno curve for the older 267lbft engine cal and had no knowledge of the 310lbft cal, even though it is right on their website. Some forum members say it's 4200 rpm. If you get on YouTube and search for Foton 2.8 diesel, there are a number of videos that show the dash board with a tach redline of 4500 rpm.

 

[ame]

ZF5 / AtlasII combo





One thing I haven't nailed down is what the actual redline of the R2.8 is. The Cummins customer service guy said "he thought" it was 3600rpm, but he wasn't sure. He also gave me the dyno curve for the older 267lbft engine cal and had no knowledge of the 310lbft cal, even though it is right on their website. Some forum members say it's 4200 rpm. If you get on YouTube and search for Foton 2.8 diesel, there are a number of videos that show the dash board with a tach redline of 4500 rpm.

High idle / redline / max RPM is usually listed on the engine data plate, not sure where it is located on a 2.8 but should be timing cover or valve cover.

 

[Cooper]

Excellent ! I've read your build and EFI Mega-Squirt threads. This, I suspect, is going to make for some good reading.

 

[Orig93gt]

Subscribed. Very interested in these.

 

[661buster1963]

if you get tired of tripping over the 351w with lots of high rpm horsepower l have a 69 F100 looking for a new engine to push it down the road, just saying.

I get jealous of you guys that know how to install engines that ford never though about putting in an early bronco, my talent is not quite that deep. Makes for great reading though and the thought of a torquey power plant that gets close to 20+ mpg sounds awesome.

 

[Digger556]

sub'd

Interesting that the total volume of the 2.8L looks to be bigger than the total volume of the 5.8L. Lots of 'stuff' I'm sure. Love our 12v, will be interesting to see how this plays out.

I had a few people ask about this, so I threw the intake and induction back on and used MS Paint to bring the crank centerlines level with each other. Now my 5.8 is not as compact as an Explorer 302, but they don't look so dramatically different now.

 

[73azbronco]

Neat.

Might also look at rear end ratio to help with lower rpm. I was going to buy a turbo diesel pickup and noted none of them came with less than a 3.5 ratio, no 4.11, because you are using torque not HP.

To be fair to the 351 though, you could have turbo charged that to keep the power at altitude like the diesel. I am not sure if or how much the diesel turbo boosts at sea level, I think it is mainly for altitude compensation.