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Discussion Starter #1 (Edited)
So it's been a long time since I have taken on a diesel project. It seems fitting that this one is kind of different. I have recently picked up a 93 4 cylinder 2WD ranger from a very close friend. He has owned the truck for the past 7 years and needed a little more space for other projects.

Goal:
So what's the goal I need all this you ask? Well to the short response is a 30 MPG small pick up that can still pull a small 5x10 utility trailer and get out of its own way. This is definitely a tall order to fill so here's the game plan.

How are we going to reach our goal:
Reducing weight, overdrive transmission, manual trans vs automatic, better gearing, allowing the motor to breath with out restrictions, basic tuning to maximize our combination.

Power:
As for power the tired ford 2.3 Lima was only rated at 100hp/133tq at the fly wheel. Even if we swapped a newer 2.5 Lima long block in the factory rating is still only 117hp/149tq at the crank. I feel confident a well maintained OM617 with the basic mods and pump tuning can put those kind of numbers to the ground with no issues. Meaning if we can get a realistic 115/165tq to the wheels with the OM617 we would have far out performed the factory motor considering the power loss from the drivetrain to the wheels.

Weight:
The ranger has a small weight advantage tiping the scales at about 3000-3100lbs compared to the 300D at roughly 3400-3500lbs. This is a good steep in the right direction since the 300D typically gets high into the high 20s for MPG to start with.

Transmission/clutch:
For the transmission we will be using a ford 5 speed. Using the 5MOD-R2 gives us almost the exact same gearing as the MB automatic from first to forth gear but of course has the huge advantage over the MN auto since the ford transmission has over drive. R2 transmission out of a 2WD 4.2 F150 is a important part since the shift lever sits back more on the newer body style trucks. This sits the shift tower closer to the rangers factory shift hole. It also shares the SBF bell housing unlike other newer body style fords that run the 4.6 or 5.4 mod style bellhousing. Since the 4.2 does use the SBC housing we can use aftermarket adapters for a clean install. We will be using a stock 4.2 duralast clutch since they are cheap and have a life time warranty. I don't expect any issues with a stock 4.2 clutch behind a OM617.

Rear and gear:
Currently the ranger has a stock 7.5 ford rear end with 3.55 gears. However this will eventually be swapped out to a stronger explorer 8.8 LSD disk brake rear end with 3.73 gears. This hearing was selected to give use better performance in first to forth gear but still allow us to lower our cruising RPMs slightly in 5th. Our finial drive ratio in 5th gear with this combo is 2.98 slightly lower then the 300D factory 3.08 Final drive with a 3.08 rear end of course. Since the rangers tires are roughly 1.5 inches taller this combination lowers are cruising RPM at 70 mph by roughly 250 rpms. This is only a about 7% reduction from what MB originally intended the OM617 to cruise at in top gear.

Tires:
For tires we don't plan on running any thing special. Probaly the stock 15 inch rims with around a 26 inch stock tire on all 4 corners.

Motor:
For the OM617 her self nothing special is planed. We will be using the stock MB PS pump and using it to power the ford steering and hydra boost brake assists. EGR delete, timing, boost, and injection pump will be adjusted as needed for best economy/performance ratio. And the exhaust will be a 2.25 inch turbo back into a free flowing muffler and exit in the stock location.

Cooling:
Cooling will depend on space once we get every thing in there but I am hoping we can massage the fire wall and slide the engine back enough to run a radiator in the stock location. No AC on this rig and really don't need it.

Fuel:
For the fuel system we will be using the stock fuel tank with a draw tube and electric fuel pump removed. The plan is to use the stock OM617 lift pump with a fire wall mounted commercial fuel filter.

Oil/lube
For oil cooling I would like to use the OEM MB oil cooler and lines but we will have to see if that's possible. Also we will need to figure out if the oil filter will need to be relocated or if it can stay in the OEM location.

So what do you guys think. We are still in the planing process so don't hold back.
 

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The Benz has an adequate vacuum pump already for the brake system, as well as a fuel filter. Stock radiator will be fine.
 

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Discussion Starter #3 (Edited)
The issue with the radiator is how long the OM617 is compared to the 2.3/2.5 Lima motors depending on how far back we can set the motor will determine if we will need to move the radiator forward of the stock location.

The hydralic booster isn't something that is needed however I do not trust vac pumps on diesels. We live in the mountains and at least with the hydraulic system you have built up pressure for a few assisted brake applications vs a vac boost set up.

I also was hoping some one could point me in the correct direction. I remember a company in California that rebuilds/upgrades the stock OM617 turbos. It's nothing fancy just a slightly bigger inducer wheel and bearings. I want to say they charged $450 per turbo or something like that. I am considering the TD04 route as well but want to keep cost down and reliability up.

Also planing on running a boost and EGT gauge of course to make sure every thing stays in safe operating ranges.
 

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Here are some tidbits from my swap experience:

Motor: If your donor MB is in good running condition don't mess with it too much until you've installed it and driven it on your rig. While it is sometimes (okay, almost always) easier to mess with things on an engine stand, it's really nice to have "baseline" performance characteristics. Who knows, you may find the stock OM617 to have adequate power without spending lots of money on upgrades. Start with things like seals, bearings and timing, move onto injectors and the rest of the fuel delivery system, then start messing with turbos ect. Obviously if your donor turbo is shot then might as well replace/rebuild it with a better set up.

I ran a 2.25" exhaust with a straight through "resonator?" muffler. I have had no complaints about noise, the MB's are not loud engines.

Cooling: If you find that you don't have to move the radiator I would recommend using the Ranger unit. No point in messing around with fabricating mounts when you can bolt something right up. Originally my motor was cooled by a radiator for a 2.5L 4 banger. It was okay in all but the hottest Vermont day while climbing hills. When it sprung a leak I replaced it with a bigger radiator for the 4.0L straight 6. Cooling was improved.

Fuel: Make sure to give any fuel system components left over from the Ranger a good flush. Not ideal to have gas go though a diesel IP. There is no need for a bulkhead mounted filter. The stock setup on the MB's just has an inline screen up near the lift side of the IP, then pushes it through a spin on filter before heading to the high pressure side of the IP.

Oil: Don't sweat it if you can't use the stock oil cooler system. Mine was damaged and it was very easy to use an aftermarket cooler and hoses. You can get adapters to go from the metric female fittings on the oil filter housing to male AN fittings. That opens up a wide array of coolers that can be mounted any which way works best.

Boost and EGT gauges are a must in my opinion.

Replace as many seals as you can while the engine is on a stand. I need to pull mine again and chase leaks. Not a fan of the "rainbow river" when it rains...

Will you need to modify the oil pan for clearance? Keep us posted!

Best,
 

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Discussion Starter #5
Thank you for all the advice.

I am hoping to find a driving car up here for the swap. Thanks to all the road salt vehicles up here rust away and you can pick up running parts cars for cheap. This way I can at least see and hear the engine run and possibly drive it to test for any major issues.
 

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Discussion Starter #6
So I have been looking into making the swap a little more strait forward and minimizing things that it doesn't need. Lucky for me early 90s rangers are stupid simple and don't need a hole lot.

We already know that we will not be using AC so the compressor can go. However because this is a small tire 2WD truck I am thinking about doing away with the power steering and simply running a manual gear box on the truck. They are a factory option on these trucks and i could swap it back down the road if I can't live with out it.
 

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I did that with my 89 Ranger diesel swap, what a mistake! I thought it wouldn't be that big of a deal but after a few weeks of Armstrong steering, I swapped back in the p/s box. You will have even more trouble with it being hard to turn because the Benz weighs more than the motor I used.
 

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Discussion Starter #8
Did you use the factory powersteering gear box or did you completely swap out to the manual gear box with yours?

Also just wondering what motor did you end up running? And any details?
 

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Did you use the factory powersteering gear box or did you completely swap out to the manual gear box with yours?

Also just wondering what motor did you end up running? And any details?
Yeah I swapped a factory manual box, way too stiff for me so back with the power, much happier! I have a Kubota 4cyl. It weighs at least 150 lbs less than the Benz and sits farther back. I also had a OM617 in a Cherokee, so splicing the p/s hoses wasn't a big deal and the factory vacuum pump is bullet proof so I would use it, You need a vacuum pump anyway for hvac and motor shut-down as well.
 

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Discussion Starter #10
Thanks for the advice. I will definitely take note.

For us the transmission options are the R2 and the T5. So far we are still leaning on the R2.
 

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Discussion Starter #11
The R2 transmission seem s to be the better way to go for us because of cost. They are way cheaper then T5s and have a higher torque rating with a lower 1st gear ratio.
 

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97-98 puts the shifter in the stock location and 99+ is even farther back.
 

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Discussion Starter #13
Thanks for the info. The weather has been horrible here and all the bone yards are snowed in but hopefully soon.
 

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Here is my 98 M5R2 swap

18076857_1346770935404929_2834763107996521635_o.jpg
 
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