Builds Cummins R2.8 H151 Swap into 1993 FZJ80 (3 Viewers)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

I vote Racor, they are easily available and they can be drainable with the clear bottom. Can also provide plenty of filtration for that size engine in a small package.
 
Now perhaps someone with some diesel swap experience can chime in. I dont seem to have space for the massive cummins fuel filter assembly. Until proven otherwise I am going to assume that Cummins does not have a shorter filter for me to use. Does anyone have experience with racor filters?

I am thinking that a small racor assembly could be bolted to the old 1fz evap canister bracket.

Any ideas?
Is it a bowl or spin on? I’m using a shorter one on my 12v because I ditched the wif sensor. I don’t know but I would guess that Cummins uses the same thread pitch on the filters.
 
:clap:

Spectacular work and documentation. I appreciate the work that goes into documenting a build/project with a highly detailed thread. I can’t do it.
 
I work on diesels for a living so here's my
.02. You should use what ever filter Cummins tells you to use or a smaller one that has the same specs as the original. You should also have as fuel water separator. This will make your other filter last longer and save your fuel pump and injectors. Ideally the fuel water separator would have a heater and and sensor for a water in fuel light. I would also put a vacuum gauge on it so you know when it's starting to get full. I have access to Cummins quick serve and can look up the filter specs for you. If you want to know more send me a PM.
 
I work on diesels for a living so here's my
.02. You should use what ever filter Cummins tells you to use or a smaller one that has the same specs as the original. You should also have as fuel water separator. This will make your other filter last longer and save your fuel pump and injectors. Ideally the fuel water separator would have a heater and and sensor for a water in fuel light. I would also put a vacuum gauge on it so you know when it's starting to get full. I have access to Cummins quick serve and can look up the filter specs for you. If you want to know more send me a PM.
Can you detail a bit more about the vacuum gauge method?
 
I believe it would work like the gauge on Chevy truck air filters, when there's too much restriction it creates a vacuum and has an indicator, or low pressure sensor.

I would think a racor with the same micron filtration or smaller would be acceptable, I like that they have clear water bowles on the bottom and are easy and quick to drain, you can get them with diaphragm primer pumps as well I believe.

Can you not relocate the Cummins filter assembly somewhere on the firewall or along the fenders?
 
Last edited:
Cody is correct. The vacuum gauge goes between the fuel water separator and the lift pump or injection pump. If there's a restriction you know instantly
 
I know it’s a different engine but just test drove the Chevy Colorado with 2.8 duramax and im underwhelmed to say the least. Mpg for 4700lb mid size truck is 18-22(RS2 off-road version) and power is just a little better than the 80. Hope the Cummings gets better MPG because at well over 1000lbs heavier and much worse aero dynamics how much better MPG will it be from current 4.5? Putting that duramax 2.8 in the 80 I bet the iron pig still won’t get to 60mph under 11 seconds with 160hp and 360lb of torque. Even an old 4bt can do that and 6bt is more better, I have completely lost interest in modern diesel swap at this point. LS3 swap can get almost the same MPG with tons more power.
 
Better MPG? hahahahahaha no.

Less power, more struggle (effort) on the engine, more weight, less aerodynamic, worse transmission gearing... more fuel used.
 
Better MPG? hahahahahaha no.

Less power, more struggle (effort) on the engine, more weight, less aerodynamic, worse transmission gearing... more fuel used.

Yes, hence the drive to put a small Diesel engine in a 6000lb 80 seems futile to me. And diesel now and days is a dollar more per gallon.

Hats off to OP on the project and can’t wait to see the results.
 
LS3 will likely get nearly 1/2 the economy, just saying.

As for the fuel filter, I'm running a Racor on my 24 valve 1HD-FT swap. I sourced a "medium" sized model with the hand primer and clear fuel bowl. It's capable of running a 12V preheater but I haven't installed one yet as the winters are not terribly cold here in Wa. I use 2 micron filters which is about as small as you can go, I doubt the factory Cummins filter can do any better. In over 35,000 miles of driving, I've yet to get any water in the fuel/water separator. Zero leaks and filters are easy to source at just about any commercial trucking or marine location. They are a touch pricey though.
 
Yes, hence the drive to put a small Diesel engine in a 6000lb 80 seems futile to me. And diesel now and days is a dollar more per gallon.

Hats off to OP on the project and can’t wait to see the results.

I would agree and disagree with this, but it depends a bit on intended usage.

If your idling down rocky creek beds and trails all day, that engine will dominate the mileage of any gas engine. They burn surprisingly little fuel when idling trails, and the torque curve it will produce is not much of a compromise for that purpose. Even putt'ing down back roads at 30-40mph that thing will just barely sip fuel in comparison.

Wayne ( @crushersrule ) mentioned someone in eastern Canada swapping a 3B out of a BJ60 into an 80 series and retained the trans and T-case, he said it performed well, we thought it would be underpowered for the 80 platform, he said it was enough power to do what the owner needed, certainly not a power house (92-100hp stock NA) but it got the owner around just fine, and that motor is underpowered next to that little cummins donk.

Now, if you drive 80mph 45 minutes to work and back everyday, and are accelerating to pass alot that little engine may not be ideal or have the power you want out of your investment, if you plan to pull a heavy trailer or boat with lots of stop lights and long hills, there are more powerful alternatives and I couldn't argue the point. It also won't have a ton of power to spin the tires, clear the mud out of the lugs or to drive like a rambunctious teenager.

I did have a BJ60 with a turbo'd 3B, it was not great for power, but putting through trails and rocky creek beds it performed well and is a simple and strong little oil burner, I do like that engine and would consider putting a turbo'd 3B in an 80 series with tires up to 35" or so.
 
Last edited:
I would agree and disagree with this, but it depends a bit on intended usage.

If your idling down rocky creek beds and trails all day, that engine will dominate the mileage of any gas engine. They burn surprisingly little fuel when idling trails, and the torque curve it will produce is not much of a compromise for that purpose. Even putt'ing down back roads at 30-40mph that thing will just barely sip fuel in comparison.

I agree. The Land Cruiser's soul is in dirt touring, and for that, where mileage and range suffer with a gas motor, this seems like a great option.
 
I have a 4000 lb travel trailer. The 80 chassis handles the weight very well but the 1FZ struggles with the western US trifecta of elevation, grade, and high speed limits, throw a headwind in the mix and I get 4.5 mpg coming out of Moab, struggling to hold 50 mph on 2 lane highway clogging traffic.

My Ram 2500 with 5.9 got better mpg than my 80 even though it was much bigger and weighed over a ton more and barely noticed trailers.

I have been searching for something that’s about 2/3 of a 5.9 powerwise AND quieter (no 4BTs for me).
 
A lot of people will be disappointed by the MPG of these four bangers.

If you plan on doing this swap for MPG purposes, you are doing it wrong.
If you get 10MPG currently and the diesel swap will yield 15MPG, that's a 50% increase in fuel economy. But, is 15MPG something to celebrate?
In the city a 2.8 diesel will be just as efficient as 1FZ.
Diesels are not efficient when RPM fluctuates. They love to be at a constant speed. Stop and go traffic? Not impressive by any means.
 
I have a 4000 lb travel trailer. The 80 chassis handles the weight very well but the 1FZ struggles with the western US trifecta of elevation, grade, and high speed limits, throw a headwind in the mix and I get 4.5 mpg coming out of Moab, struggling to hold 50 mph on 2 lane highway clogging traffic.

My Ram 2500 with 5.9 got better mpg than my 80 even though it was much bigger and weighed over a ton more and barely noticed trailers.

I have been searching for something that’s about 2/3 of a 5.9 powerwise AND quieter (no 4BTs for me).


12MPG at best?


Anyway, I guess you are looking for a 3.0 6 cylinder diesel.
There are a few choices here.
Mercedes has a few offerings, VM Motori (the same 3.0 V6 found on a Jeep Grand Cherokee diesel), BMW I6 3.0.
With torque ratings from 370 to 500lb/ft those "little" engines are more than satisfying.

You would also need to look into keeping the same transmission they were initially paired up with.
80's transmission is not well suited for the intended gasoline engine it came with anyway.

It all depends on how much money you want to throw at it and what compromises you are willing to make.
 
A lot of people will be disappointed by the MPG of these four bangers.

If you plan on doing this swap for MPG purposes, you are doing it wrong.
If you get 10MPG currently and the diesel swap will yield 15MPG, that's a 50% increase in fuel economy. But, is 15MPG something to celebrate?
In the city a 2.8 diesel will be just as efficient as 1FZ.
Diesels are not efficient when RPM fluctuates. They love to be at a constant speed. Stop and go traffic? Not impressive by any means.


Where are you getting those numbers from? Thats pretty low compared to what I'm seeing on the net. For example 25/30 for a jeep on 38's which is double what your quoting.

I would say it's not the stop and go traffic, its the acceleration when the light hits green that sucks it back.
 
Where are you getting those numbers from? Thats pretty low compared to what I'm seeing on the net. For example 25/30 for a jeep on 38's which is double what your quoting.

I would say it's not the stop and go traffic, its the acceleration when the light hits green that sucks it back.

There is no diesel SUV sold new on the market with such a great fuel economy. 30MPG. That's fantasy.
Those brand new SUVs have 8 speed transmissions, are very aerodynamic compared to the bricks we all drive, are much lower to the ground and low drag and friction tires.

25/30MPG for a diesel Jeep on 38's? Bull****.
 
12MPG at best?


Anyway, I guess you are looking for a 3.0 6 cylinder diesel.
There are a few choices here.
Mercedes has a few offerings, VM Motori (the same 3.0 V6 found on a Jeep Grand Cherokee diesel), BMW I6 3.0.
With torque ratings from 370 to 500lb/ft those "little" engines are more than satisfying.

You would also need to look into keeping the same transmission they were initially paired up with.
80's transmission is not well suited for the intended gasoline engine it came with anyway.

It all depends on how much money you want to throw at it and what compromises you are willing to make.

You’re right, I figure I am looking for 3.0 diesel. I keep hoping a shop will figure out how to make the EcoDiesel and tranny ecu and harness run stand alone as is commonly done for LS. So far, haven’t found anyone doing it.

Banks sells their version of the 3.0 EcoDiesel for (cough, cough) $29k++.

I am wondering if the GM coding is easier to work with, EFI live came out quickly for the Colorado 2.8. They might crack the 2020 3.0 I6 quickly too. I dream of that being the LS swap of diesels for 80s.

Although now that my kids are about to start leaving the nest, I’m thinking about joining the dark side. Wrangler PU with 3.0 diesel comes out in the next year. Cost and pain of swapping is going to be $20-30k, over half the price of a new Jeep.

@PurpleFJ62 sorry about the thread hijack. You’re work is absolutely amazing, thanks for sharing! Mud is full of guys in the US that are bitter at Toyota N.A. for not offering diesels and other overseas goodies in the US (especially 70 series). You’re building my dream rig from 20 years ago: an HDJ (output equivalent) and a 5 speed manual.
 
Those brand new SUVs have 8 speed transmissions, are very aerodynamic compared to the bricks we all drive, are much lower to the ground and low drag and friction tires.

25/30MPG for a diesel Jeep on 38's? Bull****.

I discovered the hard way that the 200 mpg is WAY more sensitive to mods than the 80. I.e. bumpers and tires affect 200 mpg more than 80, which makes sense as 200 mileage gains came from aerodynamics.
 

Users who are viewing this thread

Back
Top Bottom