Cummins 4BT & Diesel Conversions Forums banner

1983 mercedes om616 diesel into a 1971 jeep cj5

48K views 61 replies 13 participants last post by  SirNik 
#1 · (Edited)
Some Basic info about the jeep

1971 Jeep CJ5 350 th350 dana 18 with warn overdrive and dana 44 rear dana 30 front 4.27's


Well i bought the om 616 as noted. Ordered the adapter kits from Bob http://www.transmissionadapters.com/Mercedes diesel.htm




and ordered the oil filter conversion setup from here

http://www.peachparts.com/shopforum/showthread.php?t=168135


the stuff will not be here till next week, and im in the middle of moving into my new house that finally has a 40x60 shop so this should be an interesting buildup.


First order of business will be to confirm the overall excellent appearing condition of the engine. From there i will be gutting the 350 that's in the jeep now out and disassembling/taking off the front clip to get the engine lined/leveled up in there as best as possible.

After examining the factory motor mounts im not sure if i wish to keep them or build my own. My intentions is to keep it as much Chevy/Mercedes as possible so if for some reason it does go tits up i can walk into any parts store and get what is needed.

My next consideration will go to the transmission. Since it has a th350 in it now im going to locate and rebuild a th350c



that has the lockup clutch to give me 100% use of the diesels power band and lower my rpms even more.

after the lockup tranny is done and in there i think i will concentrate on getting the rig torn apart and i will be blasting/rhino lining the entire tub inside the passenger area and underneath the tunnel/firewall for sound/vibration dampening
 
See less See more
3
#2 ·
I have the 5cyl in my Cherokee with a 700r4. I did not use the Benz mounts as they are not strong enough to hold up to 4x4, so I used the 4bt bread van mounts ( they are a smaller version of the 6bt mounts used in first gen dodge pu's) It does transfer a little vibration, but my rig is unit-body so a full frame rig may not see the same.
 
#3 ·
you modified the 4bt mounts i assume? the stock Mercedes mounts are nice units but like you say in something that is bouncing all over and flexing it sounds like trouble waiting to happen, so i snagged a spare set to do some destructive testing to see how strong they are.


Everyone i know is burning me for using an auto in this thing, but finding a small enough 5 speed overdrive that will fit in an early cj5 isnt easy. Thoughts?
 
#5 ·
Ahh yes, I should have known. Because I have already purchased the kit to mate it to a gm bell I can't use your kit. Although cool stuff. I guess I should have mentioned it needs to be a gm bell. Of course with a full lockup converter at the push of a button and a ratcheting shifter I guess that is pretty close to a manual?
 
#7 ·
I have gotten way too much crap for my trans choice, but thats what I have and it works perfect. I chose to go this way cause I was leary of messing with the flywheel (poss ballance issues). Since I did my swap, many others have jumped on the bandwaggon and have swapped flywheels with no issues. I made my adapter myself since no one made one yet. I had to make new motor mount brackets cause the stock alum benz brackets were too wide for the frame.
 
#8 ·
im in the same boat FTE. I reviewed pages and pages of possible transmissions last night, and found very very few possible 5 speeds that are worth a darn with the gm pattern that dont weight a ton.

Among some that i found well really the only one i found worth a dam is the nv3500 that came behind 4.3's and 350's


Do most people avoid autos because in stock form dont provide 100% power grip from idle up? But with the push button activated tc lockup i would think that would be a non issue. Or is the TH350C's tc not able to lockup until a certain rpm no matter what?
 
#11 ·
My first tranny choice in this ap would be an NV4500. However a 4 speed should be great behind the Benz diesel.
 
#12 ·
How do you make a T-350 auto lock up the converter?
You cant make a TH350 a lockup. But there was a factory lockup tranny called the TH350C that came with a factory lockup circuit/converter. Drops rpm's by 15-20% and provides 100% lockup at the push of a button.

My first tranny choice in this ap would be an NV4500. However a 4 speed should be great behind the Benz diesel.
A nv4500 would be nice, but for an early CJ5 its way to huge/heavy. A four speed would be nice as well but im not gaining the "overdrive", so its not worth it.

The main reason im going with this TH350C is because i can control the transmission manually when i want with my B&M shifter and i can press a button and have 100% lockup so it will be just like a manual without having to use a clutch, and i will have "overdrive".
 
#14 ·
so the oil filter relocation plate showed up. nice work. well worth the 26 bucks. The bell housing adapter plate is to be delivered today.

I guess the only closure im going to get on the engine being externally balanced will be to take the factory benz flywheel to a machine shop and have him spin it to find out
 
#15 ·
ive got the engine mounted and mated to the transmission, everything going as planned so far. I had to get an "earl" style 240d intake and exhaust for clearance issues as they exit the exhaust at the center instead of the rear.

Do these benz motors take special coolant? Or will regular old green coolant with some DCA be good?
 
#17 · (Edited)
I can't stand it any longer. I have to ask? Do you have any idea what you are doing? I have been on this forum for several years and I have never seen a thread with so much mis information since I have been here.

First You have a 71 Jeep CJ 5 with a 350 and a TH350 D18 Warn OD. fine. Do you know why the Jeep has a 350 Chevy motor in it in the first place? It was probably put in there to replace the F-head Jeep engine that had 72 HP. That combination would not break 60 MPH! and wouldn't pull the OD most of the time. That's why it has the Chevy motor in it. I live in SoCal near the beach. When my CJ 5 had an F head engine I got passed by EVERY SINGLE CAR ON THE FREEWAY !!! EVERY SINGLE CAR !!! Mine would do 55, with no OD because it wouldn't pull the overdrive any way.

Now you are putting a 72HP MBZ diesel engine into it? I hope you live on the coast because that 72 HP diesel only has 72 HP at sea level. And since that 72 HP motor doesn't have a Turbo, figure on a 10% loss for every 1000 feet of altitude. Also OM616 motors are not really big torque motors. They are high speed diesels that were made to be economical transportation car engines. You have a very unrealistic idea of how much power these engine actually have.

You are trying to decide which auto trans to use. It won't pull an American auto trans, it doesn't have enough power! . Do yourself a favor find a different engine first. Even a VW diesel would be a better choice. The fact you have already kind of committed to this project doesn't mean you can't return the parts you've bought and get away from it. YOU ARE GOING TO BE SO DISAPPOINTED WHEN YOU DRIVE THIS VEHICLE FOR THE FIRST TIME AND CAN'T EVEN KEEP UP WITH TRAFFIC.

I have a friend who put a OM 616 motor into a Series II Land Rover which is 500 lbs lighter than your Jeep. It will do 60 mph on a good day. It is a first class installation with a standard trans, and everything was done right. He now has a Land Rover 109 with a 5 cyl MBZ 617 motor becasue he can't go anywhere in the other one because it is too slow and he can't use it on a freeway.

I have no idea why you are doing this conversion. I am sorry I have to be the one to rain on your parade but you are doing something that is so rediculous I can't help it!

Are you aware there is a MBZ section here at this site? Most all of your questions can be answered there, including the one where you ask is this a good idea and every body says no!

Sorry to be the one.

Randy
 
#19 ·
i just read this been out of town.

I can't stand it any longer. I have to ask? Do you have any idea what you are doing? I have been on this forum for several years and I have never seen a thread with so much mis information since I have been here.

short answer is yes. when concluded this will be my 6th diesel repower to date, of which 4 are still on the road with there new owners and one was lost to the flooding in 2010. I started building full size military vehicles when i was 16 and moved to smaller more realistic vehicles as i got smarter/older. my last bobbed double cab deuce was sold to a collector in NM and on his way home got side swiped by a drunk driver. upon his recovery he was so impressed with my dedication to detail he had me build him an almost exact duplicate and i shipped it to him.

1. 353 detroit to 78 chevy stepside
2. cummins 6at to 71 ford bronco
3. detroit 453t to 83 chevy k30
4. 7.3 idi turbo to 68 m715
5. 1997 powerstroke to 76 ford highboy
6. 71 jeep cj5 with a lil ol om616

im not building this thing to be a speed demon nor a power house. im building it to provide a test bed for my homemade pyrolysis machine and provide optimum economy for trail rides and for use as one of my summer drivers to work and back which is 90 percent speeds under 45.

im not worried about keeping up with traffic. if when i do get it on the long haul road for an extended period of time and it proves to be a dog ill force feed it and if it squeaks oh well it was dirt cheap. ill put another one in, sell it and build a cj7 with a turbo 617



Everyone i have talked to either thinks im off my rocker or says its the coolest thing they've ever seen....Win some, loose some i guess. I do appreciate your honesty though.


with that in mind how the heck do i post photos off my camera on here? im new to the digital camera thing and it appears i need to have a website link to attach pictures?
 
#20 · (Edited)
First: you can put the pics into a folder in 'MY pictures" of your computer and then attach them to your post with the "manage attachments" feature that comes up when you hit the "Go Advanced" button at the bottom right of a new post or reply.

Second: If you were to use a small light manual tranny like a Toyota or Nissan, and reduce the weight of the Jeep to below 2500 lbs it would probably go down the road OK. These engines in the 2500 LB cars they came in, will produce 70MPH at sea level. A Jeep of similar weight will not go as fast due to the poor aerodynamics of the Jeep body. Plus as soon as you go up in altitude the normally asperated engine will lose about 10% for every 1000 ft of elevation. The trans you want to use is going to suck 20-25 HP off the available 72HP just to run the hydraulic pump. you really don't have that much to spare.

These are the main reasons why this is not a good idea for a swap. The amount of time and money you spend to do it will not yeild a better outcome than what you already have. This is the main reason why we do engine swaps, to get better performance.

You think that you are going to get incredible fuel mileage out of this swap, and this appears to be the primary reason why you are doing it as I don't believe you actually think this thing is going to be some kind of torque monster. This is not the case at all. You will be working this little engine so hard the fuel mileage will be abismal.

I have a Jeep already built that is a case study in building something I thought would be cool only to find it was lacking is several areas. Fuel mileage being the worst part. My Jeep is the Mercruiser CJ5 built between 1991 and 1995 has a 4 cylinder Mercruiser (Chevy) 181 cu in engine with fuel injection. I had the same problems finding and mounting he engine as you are having. The end result of the $35,000 excercise, is a Jeep that works well in certain circumstances and very badly in others. The other bad being road performance which is absolutely necessary to get to where you want to 4 wheel.

MY engine has 180HP! and the Jeep gets 9 miles to the gallon, and has electronic fuel injection. It was featured in the Sept 2001 issue of JP Magazine.

If you were going to put an OM 617 motor in your Jeep I would say great. They have the same power as a AMC 6 and get much better fuel mileage. I drive a 300SD everyday and know exactly how much performance those engines have. I also have driven a 240D extensively. These cars are very slow in all cases. You are building something that is 1000 lb heaver with the areodynamics of a sheet of plywood! If you had actually driven a 240D you would not be doing this build.

Take that engine and build a 20 KW generator set out of it. It will work perfectly and last forever. Running at a constant 1800 RPM's that engine will literally run foreever.

Last: the first 5 of your repowers would lead me to believe you have some idea of what you are doing. They all should have delivered excellent performance in the vehicles you chose. You should know better by now.

This build is an excercise in futility. You said people either love it or hate it. You need to figure out which ones are actually telling you the truth.

Randy
 

Attachments

#21 ·
that jeep you built is very unique, i remember reading it back in the day and thinking wow, thats alot of work but its freakin cool.

I have considered the om617, and originally that is what i wanted to use but could not find a good runner for what i was willing to pay. Can someone give me a measurement from the very back bare part of the block where my adapter would mate to to the farthest forward part of the engine such as the hub face on the wp pulley? The reason i ask is im not so sure it will even fit in my "early cj5" with out hacking the heck out of my jeep so far i the only welding/mods ive had to do were on the motor mounts and the 616 fits like it was factory.

The one thing i have to look forward to is that if i do find out from the measurements that someone provides it will fit well i already posess everything needed to put a 617 in the old girl and can drop one in if i turbo the 616 and it blows.


Time will tell. I hope to have it buttoned up to were i can drive it on the road permanently in the next week or so.

The rig i really didnt want to sell was my highboy with the powerstroke, frickin cool ride never got above 18 mpg because it had 4.10 gears and big tires but man was it a joy to drive and fire over in the morning. But someone always wants it more than me and i give in and sell them.




i cant get the pics to work because it says i i have 342kb's of total attachments so far, yet i have nothing attached?
 
#23 · (Edited)
Don't waste your time trying to turbo a 616 motor. There have been kits available in Europe to do this but the reliability of the engine suffers tremendously as there is no piston cooling on a 616 motor like the 617 has. it is not cheap to do either. You should be able to find a 617 motor or a whole car for for less $800. ( get the whole car as you need a bunch of the piece parts to get yours running, and trying to find them individually will kill the project as they are all expensive) . I see wrecked ones all the time in Trade Express in the LA area, there should be ones available in the WA region as well. Also try MBZ junk yards and MBZ mechanics.

If you don't choose to build a nice genset out of your 616 motor you should be able to sell it fairly easily as used engines are the only economical way to keep these cars running. A long block for a 617 motor is $7000! none of the cars, even mine which is cherry is worth more than $4500 on a good day. I have seen really clean 240D's with blown engines for $300, with a $900 engine from a junk yard and some elbow grease you have a nice little transportation car for driving back and forth to work, just don't be in a hurry to get there.You can easily sell it for $2500+.

IF your Jeep was a 73 or beyond it would be an easy fit, as all of those Jeeps had AMC 6's or V8's from the factory. It is a really tight fit into a pre 72 becasue they are 3" shorter in the nose end. Still with a little mod to the firewall it will go in just fine. Also you will remove the entire radiator duct and mount the radiator to the back side of the grill for more clearance. You also need to plan on the oil cooler being included. As I stated above it would be a good idea to dump the th350. It takes too much power to run and you would be much better off running something like a Toyota 4sp trans and transfercse. There are several guys on the MBZ part of this forum that have made adapter plates and it is not that hard, then you use the crank extension you already have, the Toy flywheel clutch, starter, etc. This is the easiest type of swap to do and I have seen several done on this site that are very nice.

The one thing you are shooting for is 3000 rpms at 65-70 mph. These engines are all "Hispeed Diesels" They are designed to run at 3 grand not 1800!. That is where they have their optimum hp to torque, and wheree you get the best fuel mileage.. The 617 motors have virtually no power below 2000 rpms, even though their torque peak is at 1800. They don't make any power at 1800 because they are not on the boost. Any speed above 2500 rpms yeilds very usuable power and torque. This is why you can't use a big overdrive on the car. The engine can't pull it at slow revs. Please believe me on this last point, I drive one everyday and I know exactly what it will do. There is no OD in the MBZ auto trans. They are quite happy running down the road at 70MPH and 3 grand and will do it for alot longer than you can stand to own the car. They are very reliable engines,, as long as you operate them as they were intended to be operated. The Germans drive the shit out of their vehicles and they all are designed to be able to take that type of usuage. Mine has 270K on the original engine and will still pull the 6.5% Conejo Grade north of Thousand Oaks CA at 62 mph which is all it would ever do. That's really all anyone could expect out of a 4000lb car with a 115hp engine. If it falls below about 60mph it drops off the boost, and right lane here we come. I drive very aggressively to avoid falling off the boost as the car won't get out of it's own way otherwise. You'd have to drive your Jeep the same way.

The key to the whole build is to keep the vehicle as light as possible. Even that 616 motor would work well in a 2000 lb car. (at sea level) still you are handycapped by the non turbo. I have seen several CJ2's 3A's and 3B's with 616 motors, but they just don't do well in the mountains even at 2500lbs. An OM 601 motor, the 4 cyl version of the 603 6 cyl ,and 602 5cyl diesels have turbos and about 90 hp and are much better choices. They come from 86-95 190 D's and are Semi computerized. once again get the whole car. I have seen a Suzuki Samurai with one of these and it works well everywhere, also the VW 90 hp TDI non computerized motor works well in light 4wd's. This is the engine of choice for Samis'

Go to the MBZ section for info on the different adapters, goto the VW engine section for info on the light vehicle repowering. There is a wealth of info there and you can surely come up with some good ideas. IE: better than a 616 motor in a Jeep with a TH350.

Pulling out in front of a big truck with my car and not getting the turbo spinning first is very scary. I have the loaded drawers to prove it! I would have been dead in a 240D.

Randy
 
#24 ·
The Ebrake on the my CJ5 with a D18 transfercase was my invention in 1992. I was the first to do it to a jeep. It worked OK and it has been copied by many.

The one on my Scrambler project is a far better execution because now I have some idea of what I'm doing after working on this stuff for 25 years.:rasta:

Randy
 

Attachments

#25 ·
I like the build in question....I like it....I like it....I like it....except the transmission. Randy is right and I feel that just about any automatic you could throw at it would kill the horsepower. I was googling the adaptor relocation for my om616 build when I found this website (snooped around here in the past reading things).

I am doing a 1970 postal Jeep OM616 Ax15 Dana 20 or Dana 300 tc. My build is not set in stone with the parts I'm going to use but I'm closing in. I daily drive an 83 240D Mercedes with a 4 speed manual. It is slow and I don't care. I merge onto freeways and people hit there brakes. I am that guy who is doing 30mph up the on ramp hill petting his dash and saying "come on betsy, you can do it." Curb weight displayed all over the internet says the mercedes 240d weighs 3250lbs. My DJ jeep curb weight is suppose to be 2200lbs. I assume I'll be adding 300lbs of 4x4 stuff to the jeep. 750lbs lighter will be a blessing in disquise. Adding the 2.5" lift and 31" tires......probably not helping me. I will be using 4.56 gears when my jeep is complete and finished the way I like it. 4.56's would be equivelant to the stock 3.69 gears in the 240D car. According to how it looks on paper....the car gets 30mpg now. I figure 750lbs lighter would probably net me 35-37mpg.....adding lift and 31x10.5 tires....probably right back down to 30mpgs. I am building this for mpg and do not mind sitting 60 mph in the right lane. I would probably never take this jeep on anything more than a 50 mile TOTAL city/freeway drive at one time. I have other vehicles or access to other vehicles to go further.

Res0wc I would like to keep hearing more about your project or keep in contact. I would like to see your engine mount set up. I had planned on running some engine mounts that are for sale by the company with the ax15 adaptor. Also I assume that your keeping 4x4. How long is your driveshaft? I know its a tough fit. I plan on modifying the front grille/radiator set up. I rather create inches up front than modify fire wall. From what I have found out....I may only need aprox. 4-5 inches keeping my driveshalf at 10-11 inches long. My Email poetrynightmare at yahoo dot com
 
#26 ·
Just so peeps know- That AX-15 adapter is not 100% ready to go out of the box. there are 3-4 holes that ARE NOT lined up right, and you will need to hog them out. the crankshaft adapter is a nice piece, fits very well. but the engine adapter plate- it needs some love....

as for balance- we just did an 82 om 617 turbo and the flywheel was off by 3/16oz. very close. so close it may not of mattered at all. but for $75, piece of mind is worth it.
 
#27 · (Edited)
The transmission I chose was simply because it was already in the jeep and according to bob, the guy I got the adapter plate setup from it will fit any gm auto or manual. Im still not objecting to a manual tranny and in fact I would prefer one. But with that in mind it would mean figuring out what I need for to do for the transfer case adapter. I believe it is an advanced adapters, but im not sure. I would have to check to see if the same adapter used to mate the turbo 350 can be used to mate a manual gm tranny as now that I have my nice adapter for the engine to tranny,im stuck with gm.

Any ideas for a tranny that has that bolt pattern etc? ive heard that an nv3500 with a gm pattern is out there although I have never seen it. An sm 465 is a huge transmission and would be overkill. Randys idea for the yota setup isnt a bad idea but since I already have a gm setup id like to use that. But i suppose if i can find a decent sized five speed with od that has the chevy pattern i can use the transfer case from that rig as well.


I have no clue on fuel mileage yet as I am dealing with oil pan to diff clearance issues. Even if I only get 20mpg that is still four times what Im getting now and it will be running for nearly free off pyroil.

I have a hard time believing that my jeep weighs more than a 4 door sedan. But only the scale will tell.

As far as gears go I would prefer to do it the way I have with most of my rigs and go 4.89's or whatever the lowest grunt gears were available, assuming you were to use a five speed overdrive and have the warn overdrive on top of that.

The detroit powered k30 I built had 4.56 military axles and had 33's a nv4500 plus a gear vendors, doesn’t get much better than that, torque whenever you needed it.

Yes, all jeeps should be 4x4 or I wouldn’t own it. My rear shaft with the turbo 350 is about 16 inches extended 14 idle and 12 compressed or so.

This motor actually fits like it belongs in the rig and as far as the mounts go i can tell you that the cast ones from mercedes are not up to the task of heavy 4x4 use. I made my own from 3/8 plate and 2x2x1/4 tubing and an energy suspension "universal mount" http://energysuspension.com/products/Transmission-Mounts.html its the mount that is the left one in the pictures down below the page a bit with the 1.5" center to center distance. It is super beefy and it has a slight standoff so the poly part of the mount is mounted down firm to isolate vibration etc etc....good stuff.

I know some of you may say hey! thats a tranny mount! But i have used these for years and have NEVER broke one. And they are so universal that i can make it fit anything, and buy them at my local napa. MADE IN USA!

Other than it being a front sump oil pan it fits like a glove. I will tell you this, I already have a spring over lift and 33's and I have oil pan issues. So make no mistake, you will have issues. If only there was a way to rear sump these things.


As for the ax15 stuff I have no idea, but can tell you that bobs stuff that I ordered is dead on accurate, he knows what he is doing.



i suppose im going to have to figure out the photo sharing stuff so you all can see this.
 
#28 ·
You could always cut and trim excess metal from lower oil pan. Might be able to create a couple inches clearance from that. Otherwise were stuck messing with the front sump oil pan. On my DJ Jeep I was thinking about moving the cross brace that supports stock engine mounts. Move it back a few inches. Creating the space I need for the oil pan. Not sure about CJ Jeeps and the possibilities of this.
 
#29 ·
My Cherokee weighs 3900lbs with 1/2 tank fuel with me in it, I get 25mpg average in town and have gotten as high as 31mpg on the freeway. I have 30in mud tires and 411 gears, sweet pot is @ 65mph. As for the oil pan, there isn't much you can do but I didn't modify it at all.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top