Digger's '69 Build Thread

[Digger]

I ended the weekend by putting her face back on, hooking up the LED headlamps and turn signals. I found some LED turn lamps that were very low profile, which was needed to fit in front of the CAC.

[Jesus_man]

I wish I were closer to just come lend a hand and take notes.

[Digger]

You're welcome to stop by if you're in the area.

[Digger]

Wiring the dash side harness was the last step to get the engine running. I pulled the whole thing apart and removed some redundant wiring that came with the Centech harness, like dual hazard circuits.



I also pulled apart the Cummins harness and shorten it quite a bit.



Then put things back together




I finally received all the t-fittings I needed to complete the cooling system air bleed lines


And made an adapter to connect the reservoir return to the lower radiator hose

[Digger]

Tonight I finished the last electrical connections, assembled the intake, added fluids, dumped 5 gallons of diesel in the tank and pushed her outside...









I had to crank it quit a bit, even after priming the fuel lines, but the R2.8 popped right off on the 2nd try.

https://www.youtube.com/watch?v=OHDu5D8P15Y

[Digger]

Another quick video:

https://www.youtube.com/watch?v=M2Psvz1y6PQ

Initial impressions:
The R2.8 is really smooth for a diesel and not as loud as I expected. There was no noticeable diesel smell just standing around listening to it idle. I had to get my nose right to the tail pipe to really smell it.

Driving around the neighborhood, its a little sluggish off the line, but the boost comes on quick and then it really pulls hard, even at low rpm. Below 2000rpm, this engine pulls better than my 351W did. I will say the transmission adapter added a lot of rotating weight which doesn't help the engine get up to speed. Overall driving was pleasant. One surprise was chirping the rear tires by getting out of the gas quickly. I tried it a few times just to be sure, but in low gears, the engine pulls down fast, maybe due to the throttle body in the intake.

I need to button up a few things tomorrow and double check everything is tight and leak free, then I'll go for a longer drive.

[Rox Crusher]

Helluva impressive project

Congratulations!

[phyler]

That's sweet! Gonna make the cars and coffee at the outlets Saturday? [emoji16]

Sent from my KFKAWI using Tapatalk

[Justin]

So, so cool.

[Eck]

Milestone, baaabbbyyyy! Congrats!

[Jesus_man]

Yes!! Time for celebration!!!

How many pennies do I need to save to have you do this to my bronco?? LOL!!

Can't wait to see you enjoy this more!

I am sure the driving technique will take some getting used to! The engine braking effect might be kinda nice! Save those brakes!

Without a doubt, you have he highest quality install of this engine in a bronco, if not in ANY vehicle! I hope to see it in person someday!

[BOBS 2 68S]

NICE !!!!!!

[mickphatmac]

HOT DAMN!!!!
I thought for sure you would run a straight pipe Fat Stack up through the floor right behind the passengers seat and let that puppy ROLL COAL!!!!!!!! LOLOLOL!!!
Amazing work and Congratulations!!

[Digger]

That's sweet! Gonna make the cars and coffee at the outlets Saturday? [emoji16]

Sent from my KFKAWI using Tapatalk

The boys are playing football through this month, so it will have to be June. I already missed a couple of games to finish the engine swap.


Thanks everyone for continuing to follow this long-winded thread. I did basically straight pipe this thing, but its still not loud. Haha. Probably need an extra injector to roll coal.

[BroncoRaider]

Incredible

[TOOLMAN]

Sweet! Nice work! Thanks for including us in the journey.

[landshark]

Great job, canΓÇÖt wait to see it in person

[D&D72]

Ridiculously awesome!

[Digger]

I drove the Bronco to work on Friday. Nothing eventful, but fuel consumption is noticeably lower than the 351. Based on the 1/4 tank I've burned so far, I'm getting roughly twice the range, putting me in the mid-20s for mileage around town. I'll need to burn a few tanks to get a solid number, but it's encouraging so far.

Here is a video from one of my test drives.

[Kinder]

Congrats! It sure looks like it gets up and goes based on the video.

[Digger]

Congrats! It sure looks like it gets up and goes based on the video.

It does pretty well. I'm very happy so far.

Right off idle it is slightly more sluggish than I expected, but the turbo kicks in and then it pulls hard. I changed my clutching habit slightly by getting on the throttle a little harder and faster and that gets the turbo going sooner, then it pulls hard off the line.

It's worth mentioning that I have maintained all the emission equipment and the stock tune. From my vantage in the driver's seat, looking at the tailpipe, I cannot see visible smoke when accelerating.

I imagine this engine is capable of snappier performance off idle at the expensive of emissions, but it is not tuned that way. You can tell the fuel rolls on more slowly than my 7.3 Powerstroke.

[Jesus_man]

Those are some good MPG #'s, especially doorless.

[Digger]

A guy in California has 2 R2.8 powered rigs, a 60-series Land Cruiser and a lifted CJ-7.

The 60-series gets 22-26 mpg depending on driving style and 18 mpg towing a ~12ft enclosed trailer.

The CJ gets 25-28 mpg city, 22 mpg hwy amd he got 33 mpg holding a steady 55 mph.

My take is that the R2.8 is very capable of impressive numbers if you can minimize wind drag. A Chevy ZR2 with a 2.8 Duramax can pull 25-30 mpg with its better aerodynamics.

[Kinder]

When you get some miles on it with & without your trailer IΓÇÖd love to hear what kind of mileage you are getting based on weight & type of driving. ItΓÇÖs been a bit since IΓÇÖve tracked mine, but the best I ever got was 26 mpg town/freeway with no camper or trailer, and 20 mpg loaded for hunting all freeway (just under 10k lbs going to from Parker to Meeker)

[Digger]

When you get some miles on it with & without your trailer IΓÇÖd love to hear what kind of mileage you are getting based on weight & type of driving. ItΓÇÖs been a bit since IΓÇÖve tracked mine, but the best I ever got was 26 mpg town/freeway with no camper or trailer, and 20 mpg loaded for hunting all freeway (just under 10k lbs going to from Parker to Meeker)

Will do when I get some data points. I've driven nearly 500 miles, but haven't burned a full tank yet. I started on a partial tank and have 250 miles since I topped it off.

What are you seeing for EGT's when you are moving 65-75 mph? 45-55 mph? The R2.8 seems to run hot at 800-1100F, but I've only been above 1200F once and never made it above 1250F.

I'm use to the 7.3L cruising 75mph at 3-4 psi boost and 700-800F. The Cummins is different animal running 75 @ 22psi and 1000-1100F

[Digger]

Got my first mileage read today.

23 mpg driving a mix of 75 mph interstate and stop-n-go commuter traffic.

[Kinder]

As far as EGTs w/ boost & speed numbers IΓÇÖm running about 800 EGT @ 16-18 psi while doing 70 mph on mostly level terrain w no trailer. When I pull Mtn passes empty IΓÇÖm at 1000 EGT @ 20-22 psi to maintain 65-70 mph. Loaded for hunting / camping with trailer (9865 lbs) I try to keep it under 1100 EGT @ 24-26 psi to maintain 55-60 mph.

Your reported mpg is great!

[Digger]

Since the board is back up, time for some content...

My original transmission was purchased as a rebuilt unit from a shop. It ran fine for 10,000 miles, but something failed I couldn't totally nail down the problem and switched to my backup transmission. If you saw the truck it came out of, you'd never trust it, but the backup was a worn, but good transmission. Fast forward several years and it was time to rebuild the backup. I've been low on time, so I purchased another rebuilt trans and sent the original back as the core. I will rebuild the backup in the future. Here are all three lined up.


The output shaft needed to be shorted by 1/2" to fit with the Atlas



While things were apart, I checked on the Cummins adapter. (still looked good) The release collar on my clutch line OD fitting broke off at some point, so I made a new one.

[Digger]

After getting the new transmission in, I went for a drive and everything seemed normal until I got back to the house and heard a clicking I didn't remember hearing before. After another test drive, I isolated the transmission with the T-case, but the noise was still there. When I got home, I pulled the rear pinion, thinking one of the teeth was chipped.

Well, it was chipped and more, with 4 of the 9 teeth broken. Thinking back before pulling the transmission, I remember the drivetrain stalling for a split second when driving home one day. I wasn't 100% sure what had happened, but in retrospect it was clear I lost one tooth and it got pulled through the gear mesh and broke 3 more teeth.


It also broke the 3rd member case and trashed the ARB housing.



I performed an autopsy and determined one of the carrier bearing preload adjusters had been forcibly backed off, I'm guessing from some excessive torque on the pinion pushing the carrier over. The locking tab designed to hold the adjuster in place was bent and forced out of position. That is a lot of thrust load, but considering I have 300+lbft of engine torque x 5.7:1 first gear x 6:1 transfercase x 4.56 axle gears, it makes sense.

[Digger]

Well shoot, I just dropped almost $2K on a transmission, but lets upgrade the rear axle. First up, that factory 3rd member with its tiny bearings and wimpy adjuster needed to go because I'm an engineer and I hate deflection in my gearsets. Enter the aftermarket nodular 3rd member with giant carrier bearings and a Daytona pinion support:



I agonized over this for days, but I couldn't convince myself that the ARB was okay and rebuilding it was more expensive, so screw it, buy a new one:


If you've ever installed a RD119 air locker, it doesn't fit in the 3rd member, so you need to carefully grind the pinion support bearing and it's still tight to fit everything in there;


Patterned up and locked down:


Installed and back on the road with 100% new components. I couldn't even reuse the pinion yoke. (it was trashed too)