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5.2 Magnum or MB OM617 turbodiesel?


What engine to swap in?  

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  1. 1. What engine to swap in?

    • 5cyl OM617 Mercedes Turbodiesel
      1
    • 5.2 Magnum
      0


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Having a hard time deciding where to go next. I already have the 5.2 ZJ donor vehicle, but gas mileage is killer and the 5cyl Benz turbodiesel sounds great for getting 25ish mpg. In modded form, they can make similar power as the 5.2 and be way cooler anyway. Upside to the 5.2 is I already have the motor and wiring. Help me decide. What do you think?

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In modded form, they can make similar power as the 5.2 and be way cooler anyway.

 

Please share the mods that will produce v-8 power from an MB OM617. I've got one waiting on an engine stand I'm planning on dropping into an MJ and my DD is a MB 190d. Part of my daily net reading is keeping up with MB boards and a few diesel mod boards. You can adjust/remove the ALDA, use improved injectors, and get IP timing adjusted good to help things out but its my understanding the limitation is the IP can't deliver more fuel to increase the HP.

 

Obviously I like the OM617 with an AX-15 as a power plant for an MJ and my expectation is for it to have more useful power than the 2.5 but less than the 4.0 while delivering 25%+ better fuel mileage. I hope you've discovered something I've been missing to increase the power of an OM617 as it would make my intended re-power even more exciting to me.

 

Good luck with your project!

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In modded form, they can make similar power as the 5.2 and be way cooler anyway.

 

Please share the mods that will produce v-8 power from an MB OM617. I've got one waiting on an engine stand I'm planning on dropping into an MJ and my DD is a MB 190d. Part of my daily net reading is keeping up with MB boards and a few diesel mod boards. You can adjust/remove the ALDA, use improved injectors, and get IP timing adjusted good to help things out but its my understanding the limitation is the IP can't deliver more fuel to increase the HP.

 

Obviously I like the OM617 with an AX-15 as a power plant for an MJ and my expectation is for it to have more useful power than the 2.5 but less than the 4.0 while delivering 25%+ better fuel mileage. I hope you've discovered something I've been missing to increase the power of an OM617 as it would make my intended re-power even more exciting to me.

 

Good luck with your project!

There are guys in Finland and Sweden making big power with the 617. Of course, they upgrade to the MYNA IP which is very expensive. www.superturbodiesel.com Power from my 5.2 Magnum is rated at 220hp/285ft lbs. The OM617.952 is rated at 125hp/181ft lbs. If I were able to achieve say, 200hp/250+ft lbs, I'd be a happy man. The thing is, it will take money- a lot more than the 5.2- and I'm not sure the added fuel economy would cancel out the initial investment quick enough to be worth it. Diesel is cooler. Magnum might be a better idea.

 

My tentative plan is to run an ax15 with a Dakota 3.9 bellhousing with the 5.2 if I go that route because of Dodge's inability to make a good auto trans.

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What are your plans for your truck when you finish it? MPG should never be a factor when trying to figure out if your going to drop a diesel in because you will most likely never recoup the costs. Oh and the poll is broken :(

 

Brandon

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Well, considering my 4.0 gets 14mpg and similar swaps get closer to 25-28 out of the 617, I'd say I would recoup the money if it were similarly powerful to the 5.2 (which I need for towing and hauling). The added bonus is that the 617 is a multi-fuel motor. It can be run on veggie oil with just a auxilliary tank and tank heater.

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:popcorn: if only i could figure a way to get our 6 liter turbo diesel from the f-250 into my MJ... I would be set!. if you are going to do a lot of towing then i would go with the 5.2, 1st because you already have it, 2nd parts should be cheaper and easier to find, 3rd that added power you can play with your diff gears more. instead of using 4.10s or 3.77, you have more options of more mpg friendly gears like 3.07, and 3.54.

 

a diesel would be cool and i am all for it, you just need to figure out what is worth more to you? mpg or power?

 

just my thoughts

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As far as which motor to swap in the 5.2 would most likely be considerably easier mostly due to the front sump on the 617. I am in the middle of doing this swap and am having problems trying to get everything to clear. Plus you already have the 5.2 and parts are everywhere in the junkyard for that motor.

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drop a diesel in because you will most likly never recoup the costs.

 

What non-stock repower would ever meet this criteria and why would a diesel repower be any more expensive than a gasoline repower?

 

I parted out a rusted good running mercedes. Kept the motor and cleared enough from the crusher and selling a few parts to cover my purchase price with enough profit to buy the transmission adaptor to the AX-15 which was pretty cheap. So, the motor mated to the transmission is free (excluding my hobby time) and my expenses will be motor mount brackets (will custom make from scrap) and steering clearance of the front oil sump which 91dieseljeep is working through. Available dropped pitman arm and dropped pan hard bar (old cj name) brackets may do the trick with a little oil pan modification but these will set you back apx $300 retail. Hook up the exhaust and boddabing your a custom diesel MJ. (sure sounds simple written like this)

 

Does this strike you as being any more expensive than any other non-stock repower project?

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Only other diesel that fits besides the stock anemic 2.1 is the 4BT but that's even more expensive.

 

I've also read where these were in a very few factory produced models. The size, weight, and power of the 4BT makes me think the stock suspension, transmissions, and axles would also need to be upgraded as the 4bt can easily be tuned upward.

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Only other diesel that fits besides the stock anemic 2.1 is the 4BT but that's even more expensive. I suppose a VW TDi would fit but then you run into management problems and tranny adapting problems.

The VW TDI is not a problem. There's a kit to mate the TDI engine to a Toyota trasmission. I have a complete TDI engine in my garage for this very swap. My plan is to use an AW4 transmission.

 

My 96 Pasat puts 220 lb/ft at the front wheels with a chip and slightly larger nozzles. No turbo upgrade.

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Having a hard time deciding where to go next. I already have the 5.2 ZJ donor vehicle, but gas mileage is killer and the 5cyl Benz turbodiesel sounds great for getting 25ish mpg. In modded form, they can make similar power as the 5.2 and be way cooler anyway. Upside to the 5.2 is I already have the motor and wiring. Help me decide. What do you think?

 

 

Go for cool. Do the diesel conversion. V8 swaps have cooling issues. But are cheap. How about a big stroker?

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Go for cool. Do the diesel conversion. V8 swaps have cooling issues. But are cheap. How about a big stroker?

 

Not if you get the correct radiator and fan set up. A stock MJ rad will barely keep a 4.0 happy. That is where most people go wrong with a V8 conversion. Also, a fan shroud is a vital piece of your cooling system. I am using a 3 core aluminum radiator for a Chevy on my Magnum conversion. I am still on the fence about a electric fan of mechanical fan with a shroud. I have HD ZJ fan clutch with a newer XJ fan and shroud right now. I have not had the truck running long enough to see if I am going to have any over heating issues. I am pretty sure I got it right though.

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The Benz OM617 swap to the MJ/XL limited real estate compartment has been done many times, documented well over on the Diesel Bombers forum. We had a forum member who did it a few years ago. I researched it well before I went the stroker route. As far as getting comparable torque/hp numbers from the Benz diesel comparable to the 5.2 economically, forget about it. BUT if I were dedicated to an MJ diesel install, for sure the Benz is the way I would go. Only problem is that the OM617 will keep going long after the MJ body falls apart.

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Only problem is that the OM617 will keep going long after the MJ body falls apart.

That's why you can pick up an OM617 cheap. If the oil has been changed, after it wears out the MB body you can drop it in another vehicle and keep going there.

 

I agree with you in that there are several folks who have resolved their front sump issue, but I don't sense there is an accepted "standard" or "best" way determined yet. I've got a gameplan, but I'm not 100% confident it won't need massaging further one the motor is in the MJ.

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As far as the front sump i got my steering to clear with a 3" drop pitman arm and now i just have to figure out about the track bar. It gave me some extra room to work with using this narrowed oil pan http://mercedesdiesel4x4.com/default.aspx I have the motor mounts built for the drivers side and just the passenger side left.

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Did you find a good source for the dropped pitman arm as everything I've seen so far is over $100 which seems like a bit much for what your getting?

 

Won't you also have to drop the track bar mount 3" to keep the track bar and drag link in the same plane to avoid "death wobble"?

 

Do you have a build thread anywhere as I'd love to see pictures of the specifics of your build?

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The Benz OM617 swap to the MJ/XL limited real estate compartment has been done many times, documented well over on the Diesel Bombers forum. We had a forum member who did it a few years ago. I researched it well before I went the stroker route. As far as getting comparable torque/hp numbers from the Benz diesel comparable to the 5.2 economically, forget about it. BUT if I were dedicated to an MJ diesel install, for sure the Benz is the way I would go. Only problem is that the OM617 will keep going long after the MJ body falls apart.

 

Don,

 

What kept you from the OM617 conversion? Money - meaning just not economical in the long run. Or just that the Stroker is close to a no brainer?

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Yes there really isnt a good sorce for the pitman arm for under $100 but at this point it will solve my steering problem so its worth it. And yes the track bar mount will have to be dropped to keep the gtrack bar and drag link parallel.

No i don't have a build thread I'm kinda new to this site although i have thought about making one.

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91diesel - what are you thinking? You are doing a very cool repower that tons of folks would love to follow and offer up ideas. That's some bad karma your putting on yourself by not having a build thread. Start snapping digital pictures and posting immediately!

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