to swap or not to swap.....

[spelius]

I need a couple of days to make sure if it´s possible, but It sould be...
my plan is to bold jeep np242 tranfer-case on mercedes auto tranny by using some parts from AW4, which I bought two days ago and waiting for delivery.
I want to take rear "ring which holds tranfer case" out from AW4 (can be unscrew,because AW4 can be used as 2WD or 4WD and the 2WD version has different tranny end) and make little adapter for whole dislocation to screw it down to mercedes automatic tranny. This transmission has also 2 versions, 2WD and rather rare 4WD, so I can use those screw wholes...
Now it could hold together and we need to connect shafts... From merc auto tranny stick out a thin shaft and in jeep tranfer case is a whole. So if I will take inside shaft from AW4 (which is the the one which goes into the jeep transfer-case) and make it shorter, for exact length we will need, we are done. Than we need to make whole into this "short shaft" in size of mercedes auto tranny thin shaft and screw it all down together.

 

[spinsession]

Guys, I'm sorry I've let everyone down. I had a simple task of measuring an engine and I haven't been able to do it yet. Nobody is interested in hearing my excuses, so I'll try to get out the tape tonight. My diesel project has taken the back burner position for a while, but I will try to get the measurements for you guys nonetheless.

Spelius. Your idea is very interesting. Based on what I've seen of both the transmission case and the transfercase case this might be a real possibility. Mating the shafts will be difficult, but I will be watching your progress VERY attentively. If this works, I think you might have discovered the best solution. This would eliminate any of the flywheel balancing/alignment issues and, relatively speaking, an adapter plate between the trans/transfer case would be much simpler to fab. Keep up the good work!

 

[spelius]

Mercedes engine measurements ready on www.spelius.com

Can anyone measure jeep 4 liter pls?

 

[tayman]

I just did a quick fairly sloppy measurement, but it looks to be about 27 inches (68.5cm) from the bottom of the oilpan to the top of the valve cover. kinda hard to get width when it's in the jeep...

 

[spelius]

hi guys, any progress?

I did measurements and the Mercedes engine is little bit smaller than 4.0 liter Jeep... Which is nice, problem will be, as we already know, in oil pan...
the gearbox/tranfer case adapter can not be made before we find the best possition spot for the engine.... So let´s crack on...

I have an idea - have you anyone think about relocation track bar and tie rod to make more space for engine oil pan? I am sure that axle is not problem - engine could go higher... Problem is in those bars... I have seen somewhere on the internet High Steering Kits for cherokee, what could teoreticaly helps to make little bit more space in front... what do u think?

Refabrication the track bar couldn´t be a big problem, just little cutting and welding, but not sure about tie rod system... lower tie rod could be extended ( as I have seen ) and grip on right side, but what about steering bar what goes from pitman arm? Can we relocate it somehow? I have seen this bar just mounted to right whel with no steering dumper. How can it works? Has to be too much pressure on it or am I wrong?

 

[spelius]

I was reading this thread again... what do u think about 8" lift? :wave1:

 

[tayman]

put 35 inch tires on it, and call it good!:wow:

But really, it sounds like you're really on the right track.

I would try to be more helpful, but I myself am still learning. I'll probably get more into this during the summer months when school is out. My newest question is... if the Mercedes engine is smaller, why is clearance with the oil pan still an issue?

 

[spelius]

because all mercedes engines has in front of the engine oil pan which is in opposite position than jeep... and it makes those clearence problems.
Both engines have almost similar high but above front axle the oil pan difference makes +/- 17 cm...
so the way out is to put engine further towards driver cabine (cutting firewall) or further to the front (making front longer - oil pan in front of steering bars), put engine higher by cutting bonnet or huge lift) or leave it how it is and replace steering bars...
or find the best way with little bit of this and little bit of that to make it fit :cheers:

 

[tayman]

oh, thanks I understand now. is there any way to spin the oil pan around so it faces like the jeeps?

 

[HOUSEDIVIDED]

http://www.overlanddiesel.com/71/2274.html

 

[tayman]

first of all...Welcome to !!!

I think the reason that we're looking at the mercedes engines though, if because of how common they are. You can find them in just about any junkyard, where it's difficult to find parts for something like the toyota diesel...

Thanks for the link though!

 

[spinsession]

oh, thanks I understand now. is there any way to spin the oil pan around so it faces like the jeeps?

I can't remember where, but I saw somebody attempt this. The problem is that the oil pump is in this lower sump area so you have to relocate the oil pump too. The person I saw do it opted for an electric oil pump and external oil reservoir. He then just bolted a flat plate over the "lower oil pan" opening. This will gain your about 2-3" I believe. Something went wrong for him though and his engine died due to an oil shortage. I still think that this method could be executed correctly, so I wouldn't just write it off as a failed experiment. Race cars use these electric pumps all the time. The lower oil pan is easy to modify or relocate, but if you need more clearance, dabbling with the upper oil pan will require a lot more work. The upper pan bolts directly to the engine block and it's aluminum (hacking and welding becomes more difficult if your shop isn't well equiped). Additionally, it provides half of the sealing surface for both the front and rear main seals. In short, I don't think I'd recommend too much tinkering with the upper pan, but someone else may have a different opinion on this.

 

[spinsession]

I am sure that axle is not problem - engine could go higher... Problem is in those bars... I have seen somewhere on the internet High Steering Kits for cherokee, what could teoreticaly helps to make little bit more space in front... what do u think?

I don't mean to be negative, but I do want to clarify for those reading this post now and in the future. The steering linkages are NOT the problem. The engine sits behind all of this. The problem IS the axle. More specifically, it's the differential housing. The oil sump sits directly above the pumpkin. As you have also stated though, it would be possible to mount the engine higher...but this will requiring cutting of both the hood (bonnet to spelius. ) and the firewall/trans tunnel. The problem is that you can't raise up the front of the engine without hitting both places. The way that most people get around this issue is with a gigantic lift, but that's not what I'm hoping to accomplish. Again, I don't want to criticize anybody's ideas or efforts, but I do feel it's important to keep the facts straight as we work through this project.

 

[spinsession]

I'll probably get more into this during the summer months ...

Me too. I've been busy with some other things lately.

 

[spelius]

spining the oil pan around and installing elektric oil pump is not the best way for me... It should works I guess but I do not want to destroy my rebuilt engine because a lack of oil...
I know exactly what you mean spinsession ... I do not want massive lift either.
All the time we are talking about putting the engine behind front axle ( and cutting firewall/trans tunnel) but what about moving the engine little bit more forward (to the front) so the "oil pan step" would be above diff case and the front of engine world be on place where steering linkages were. And relocate those linkages as High Steering Kit does and change trajectory of track bar?
​

 

[spinsession]

spining the oil pan around and installing elektric oil pump is not the best way for me... It should works I guess but I do not want to destroy my rebuilt engine because a lack of oil...​

I agree. An electric pump would not be my preference either, however, in theory an electric pump could actually maintain better flow to the motor. It's not dependent on engine RPM, it wouldn't be affected by inclines/declines on the trail and/or off-camber trails, etc. If implemented correctly there is nothing wrong with an electric pump. I guess all I'm saying is that you shouldn't just write this option off. I would prefer not to have to mess with another pump/lubrication system either, but if necessary I'd probably run an electrice pump before I'd run an 8" lift.

All the time we are talking about putting the engine behind front axle ( and cutting firewall/trans tunnel) but what about moving the engine little bit more forward...

I think you'd have to move it a lot bit more forward to clear the oil sump. I know that the clearance is already very tight (uncomfortably so) between the fan and the radiator. At the very least I think you'd have remove the condensor and the electric fan then slide the radiator forward. That might buy you 2-3 inches, but I think that you'd need at least 8-10" to locate the differential behind the oil sump. I thought I was going to do this swap ~3 years ago, and I hung the motor in the empty XJ engine bay. If I remember correctly, the differential was closer the front edge of the oil sump. That sump is ~12" from front to back (I'm just pulling numbers off the top of my head now). I think you'd have to move the engine forward quite a ways to get the diff behind it.

I really need to come up with an XJ shell to play with, but I really think that cutting/reconstructing the firewall wouldn't be quite as bad as it sounds. I've heard of people cutting a hole in the firewall to gain access to those two star bolts on the back of the 4.0L engine block. They normally don't have to remove the dash or any of the interior to do this (just peel back the carpet) which leads me to believe that there's wiggle room back there to slide the block rearward.

Incidentally...sliding the block back will also allow you to raise the front a little because of the hood slope. Sliding it forward will force you to lower the block a bit for the same reason. Probably not a major consideration, just a thought.

 

[tayman]

I've heard of people cutting a hole in the firewall to gain access to those two star bolts on the back of the 4.0L engine block.

I almost had to... I didn't know they were torx!

anyhoo.., is there anything we could do besides modify the oilpan? what about doing something with the front axle? is there any possible way to modify the axle?

What about moving the existing oil pump? is it possible?

I kinda like the electric pump idea, because it would allow us to use a flat pan, like stated, and relocate the pump higher maybe. then we'd have the clearance issues taken care of.

or maybe better yet, is there another very common engine we could use?:jester:

haha, just kidding. I would love to be one of the pioneers of this!

 

[spinsession]

what about doing something with the front axle? is there any possible way to modify the axle?

I've thought about trying to relocate the axle forward. I know that guys do this on Wranglers for rock crawling, but I think it would be much more difficult with a unibody XJ...and it would probably look ridiculous on an otherwise stock Cherokee. As far as modifying the axle goes, you'd need to move the pumpkin to the left (driverside), but you'd run into the lower control arm mounts before you'd clear the oil pan. I've thought about swapping an axle with the pumpkin on the other side too, but I think you'd wind up with the same problem on the right side of the oil pan. There is also the low-pinion D30 option which would lower the driveshaft/pinion down a few inches, but the clearance problem is on the top edge of the diff housing. Diff housing aside though, remember how tight to the bare axle tube that 2wd Comanche was...even with a small lift. Thinking outside the box a little, how about a Samurai axle, or something off a Toyota. Does anyone know if these axles might have a smaller diff housing? You can always get axle tubes and shafts lengthened, it's really the housing geometry that we're looking for. Anybody else have other ideas in regards to axle mods?

What about moving the existing oil pump? is it possible?

I believe the answer to this is yes, but with serious work, access to a machine shop, and a lot of luck. The existing pump is driven by a chain and sprocket mounted to a short shaft that runs into the pump. This shaft goes through a bearing carrier, which doubles as one of the main crank bearing caps. You could get more of these bearing cap/shaft carrier parts and then lengthen the pump's input shaft to run the length of the block, then remounting the pump to the back, which would allow you to reverse oil sump...problem solved! If only it was that easy in practice. You'd see what I mean if you looked at the block and the way the pump mounts. I think it's possible, but I know that I don't have the skills, machinery, or money to have this work done. So for practical purposes, I'd have to say that moving the existing mechanical pump isn't an option.

I kinda like the electric pump idea, because it would allow us to use a flat pan, like stated, and relocate the pump higher maybe. then we'd have the clearance issues taken care of.

I don't believe that the flat pan by itself will completely take care of the clearance issue, but it will be a large step in the right direction. A flat pan and a 3" lift may get the job done...and I might be able to live with that. I guess I need to look at this a little more. I'll try to measure how deep that oil pan is and see how many inches that would pick up for us.

or maybe better yet, is there another very common engine we could use?:jester:

Not in this thread! :nono:

 

[tayman]

I don't believe that the flat pan by itself will completely take care of the clearance issue, but it will be a large step in the right direction. A flat pan and a 3" lift may get the job done...and I might be able to live with that. I guess I need to look at this a little more. I'll try to measure how deep that oil pan is and see how many inches that would pick up for us.

the lift is not a problem as I'm already at 5"...

Not in this thread! :nono:

I know, I was teasin'... I want this to work just as bad as you do!!!

 

[spelius]

I am doing quotation "pistonhead" from G-wagín UK club www.gwoa.co.uk where I am doing searching for our problem as well...

what about converting to a dry sump? this is a system of oil circulation and collection applied on some Rally cars. There is no deep oil sump as such, but merely, an oil cover. In other words the deep section of your oil sump can be cut away and welded short with Tig-welder, the welder needs to be good, it is not easy to weld aliuminium.
The oil returning into the cover is scavenged out by a scavenge pump to a suitable reservoir mounted inside the cab, it is from this reservoir the oil is fed back to the engine for lubriction. This system over comes any deep filled sumps, being protected from any sump damage.
You will have to research where to get these kits from, I do not know wheather they are a universial kit which can be adapted to fit any engine or for that matter, do not have any more info. on scavanging pumps etc..

btw: The Mercedes petrol 6.9 litre engine used in the early s class is a dry sump, I believe the reservoir is on the inner wing.