Om617 96 Jeep Cherokee build thread - Page 39 - Diesel Bombers



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  #381  
Old 04-17-2017, 07:09 AM
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Quote:
Originally Posted by Hillbilly1 View Post
I found this on the cars,
The 1985 does have a higher stall speed converter installed in from the factory.
'85 is around 2400 - 2700 RPMs and the previous years 1450 - 1650 RPMs.



.
Peak HP and TQ on these engines are 2400rpm, that is the sweet spot. I don't remember but I think the transmission gearing made up for the high rear end gears. Pay special attention to gearing and lockup or it will suck.
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  #382  
Old 04-17-2017, 08:39 AM
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Originally Posted by Hillbilly1 View Post
Will a 3000 be too high? Might as well get it right before I drop mine in. The transmission came out of an S10, so should be close to a 2000 stall from the factory. Right now I'm running stock tires and wheels, but a 4" lift kit is in the future before I drop the motor in, with the winch and heavy motor will probably work out to be around 2.5-3" and I belive my present axle is around a 3.75.

running my scout 800 with 3.75 was IMO in unacceptable but for low range or high range in 1st gear
also my 1984 300sd has a rear with 2.88
Trany gearing is according to MB
1st =3.68
2nd =2.41
3rd = 1.44
4th =1
R =5.14
its also running a lot smaller tiers 195/70R14


My 700R4 came from a K10 and was backed with a NP208 .
the TC was stalling at just under 3000 and frankly sucked when I backed it up to my 4.3 even though it was bored 60 over , balanced , ported and redline HP cam . while it would maintain speed in OD there was low power and high trany temps
I switched that TC out for a S10 TC that was behind a 4.3 , rated from factory at 2375. Trans temps went down considerably and much better performance on both street and trail .literally the 4.3 went from nice to throwing you back in the seat . If it wasn't for the crappy mileage it would have still been in there scout
so depending on what engine was in your S10 you may fine the TC isn't a 3000 . if it was a 4.3 or smaller its more then likely going to be in the 2400 range . give or take .

just my opinion but I don't think your going to like the 3.73 gearing with the OM617 even on the back roads and dirt unless you get the OM617 to produce like numbers for the engine that was in the S10 at the same RPMs.


as for myself if I can get the OM617 backed by the 700R4 to be alittle better then the IH 196 which originally came in my scout , ill be happy . while the 196 wasn't a power house , it was more the capable on and off road .


I have done a lot of engine swaps through the years even though this is my first diesel swap . basically IMO there are 2 ways to approach them . either try and duplicate the performance of the car the engine came from OR modify the engine to make or hopefully exceed the power that the drive train came from with like numbers . in other words modify the engine or modify the drive train

Last edited by Captchee; 04-17-2017 at 08:51 AM.
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  #383  
Old 04-17-2017, 10:05 AM
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Quote:
Originally Posted by Captchee View Post
running my scout 800 with 3.75 was IMO in unacceptable but for low range or high range in 1st gear
also my 1984 300sd has a rear with 2.88
Trany gearing is according to MB
1st =3.68
2nd =2.41
3rd = 1.44
4th =1
R =5.14
its also running a lot smaller tiers 195/70R14


My 700R4 came from a K10 and was backed with a NP208 .
the TC was stalling at just under 3000 and frankly sucked when I backed it up to my 4.3 even though it was bored 60 over , balanced , ported and redline HP cam . while it would maintain speed in OD there was low power and high trany temps
I switched that TC out for a S10 TC that was behind a 4.3 , rated from factory at 2375. Trans temps went down considerably and much better performance on both street and trail .literally the 4.3 went from nice to throwing you back in the seat . If it wasn't for the crappy mileage it would have still been in there scout
so depending on what engine was in your S10 you may fine the TC isn't a 3000 . if it was a 4.3 or smaller its more then likely going to be in the 2400 range . give or take .

just my opinion but I don't think your going to like the 3.73 gearing with the OM617 even on the back roads and dirt unless you get the OM617 to produce like numbers for the engine that was in the S10 at the same RPMs.


as for myself if I can get the OM617 backed by the 700R4 to be alittle better then the IH 196 which originally came in my scout , ill be happy . while the 196 wasn't a power house , it was more the capable on and off road .


I have done a lot of engine swaps through the years even though this is my first diesel swap . basically IMO there are 2 ways to approach them . either try and duplicate the performance of the car the engine came from OR modify the engine to make or hopefully exceed the power that the drive train came from with like numbers . in other words modify the engine or modify the drive train
I know mine is not a 3000 stall, I was just asking if it would be any better, according to what I have found, the S10 is a 2000 stall, so 2000-2400 is probably correct, so I'm going to stick with it. I'm using the transmission and 231c hd transfercase instead of the 231j, already installed a sye
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  #384  
Old 04-17-2017, 10:36 AM
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The Germans must have some steep driveways to back out of! LOL! 5.14! The 700r is a little higher though, but lower than the Jeeps three speed auto.
700R4 TRANSMISSION RATIOS
1st
2nd
3rd
4th
Reverse
3.059 : 1
1.625 : 1
1.00 : 1
0.696 : 1
2.294 : 1
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  #385  
Old 04-20-2017, 07:56 PM
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Gear Ratio Calculator

You might try this gear ratio calculator to see if it is of any help for you. Plug in transmission, transfer case, doublers (if you have one), tire size, and rear end gear ratio to see what vehicle speeds, RPM's, 4 X 4 low axle speeds are, etc. You can run two different scenarios side by side for comparing.

Don
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  #386  
Old 06-13-2017, 10:38 PM
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Quote:
Originally Posted by Evenglass View Post
I upgraded the stock 64amp Mercedes alternator to a Bosch AL129X 115amp unit out of a 90's Saab 9000, it bolts on without any mounting modifications. Besides the power increase the AL129X has conventional wiring lugs instead of the spade harness of the 64amp unit.

These Bosch alternators are of two wire design and are self exciting with built in voltage regulator, the Jeep is three wire and require the computer to both excite the alternator and regulate the voltage. The Jeep alternators black wire with gray stripe goes to the +battery terminal, the dark green wire goes to the to the Jeep ECM, and the green with orange stripe also goes to the ECM.

The information I found online state:
Jeep Mercedes
Black w/gray stripe > Red
Dark green > 3amp diode> Blue
Green with orange stripe > Not used

I installed a very accurate digital volt meter behind my information panel by wiping the paint off the factory panel and installing my gauge in place of the "check engine light". This allowed me to monitor what my alternator was doing. I found that if wired as above the Bosch alternator is not excited by the dark green Jeep wire, revving the engine above 1600rpm creates enough magnetism to excite the slip rings in the alternator and thus self excite the alternator. Wiring the Jeep green wire does however work the "GEN" light in the information panel. I found that if not run for awhile the alternator would not as easily self excite and after not charging for about 1 minute the Jeeps computer would throw the "GEN" light on. If not run for awhile It takes about three quick revs above 3000 rpm to excite the alternator or about 30min of normal driving. Once the ECM turns the "GEN" light on the ignition will have to be cycled to reset the computer.

I believe this happens because the jeep ECM uses the dark green wire to monitor voltage output in conjunction with battery temperature sensor in the battery tray to calculate voltage output needed then sends a varied current down the green wire with the orange stripe to the alternator thus adjusting output.

If where to do this again I would test the green wire with orange stripe for power with ignition on, wire it in conjunction with the dark green wire and perhaps use this to excite the alternator. If That didn't work I would just run an ignition hot wire to excite the alternator and retain the dark green wire to run the "GEN" light. It's no big deal to rev the engine or just wait for the alternator to excite itself, I just don't like looking at the "GEN" light.






Size difference, stock 64amp vs 115amp






12.5volts at idle(not charging), about 60sec later the "GEN" light turned on




14.4volts at idle after revving to get the alternator to "wake up", this light will remain on until ignition is reset.


The alternator feeds a Diehard 850CCA AGM battery, this setup with 00aut cables and gear reduction starter has no problem turning over the engine.

---AutoMerged DoublePost---

In my opinion the most important aspect of this successful conversion is the gearing, I believe gearing is the single most common reason people abandon the conversion soon after completion. Seems most people sell their 617 conversions and end up installing a more "conventional" diesel. The most common misconception of this diesel is that it needs to be lugged down like most other diesels, this thinking is completely incorrect for this engine. The Germans engineered this engine to spin high RPM thus giving it a wide usable torque curve. In true German fashion the engineering effort put into this engine was no small task and would blow most peoples minds. Research and engineering on this scale cannot be duplicated without an engineering team and great funds.

For this reason I did not attempt to re-invent the wheel and tried to keep the RPM of the engine as close to the original German spec as possible. My 300D would turn 1500rpm at 30mph, 2000rpm at 42.5mph, 2500rpm at 55mph, 3000rpm at 65mph, 3500rpm at 77mph. It would cruise at 70mph all day for the next 350,000 miles. This engines peak horse power and torque are at about 2400rpm, it doesn't even start to boost until 1800rpm. Most diesel guys have a hard time understanding this is what the engine was designed to do, and try to gear it down the result is an "under powered engine" and ultimately an unhappy owner.

The only regret I have is that I didn't go with 4.88 gears, As it sits now with 4.56gears and 31" tires the jeep spins at about 2600rpm at 65mph, just into it's power band and I assure you would be overall better if this power band could be brought down a bit. Truth be told I planned on going with 33" tires later on but am now limited to 31" do to RPM constraints.

The Dana 30 in the jeep can only go to 4.88 gears as far as I know, if doing this in another vehicle where even lower gears are possible DO IT! Keep engine RPM as close as possible to engine design.

The 700R4 is far superior to the Mercedes unit and offers a low first gear and efficiency. I planned on using the lock up function on the converter but that is entirely out of the question due to gearing.

It is my opinion and that of GM's that if you do not follow the specified geometry for the TV cable you are doing it wrong. This doesn't mean it won't work and the transmission will explode it just means the transmission will never run as intended at the very least, and most likely you won't be happy with it. Again do not try to re-invent the wheel and try to stick to GM design as much as possible, they put millions of dollars into this.

---AutoMerged DoublePost---


Took me three days to get this to GM spec but it was worth every second, the transmission feels and shifts great. These are the templates I made to make sure everything was as close to GM spec as possible. These templates are 1.125" with 78* arc with a mark locating the 90* relationship to the TV cable at 25% throttle.





I used brackets from the Jeep, pivoting points and linkage from the Mercedes and a universal TV cable.


The hardest part was figuring how to get the stock Mercedes 50* throttle throw to the needed 78* for the 700r4, I accomplished this by moving the lower injection pump linkage closer to the center pivot by drilling small holes and moving it in slowly until it produced a 78* throw.


The last thing to do was locate the jeep throttle cable so that the foot pedal had the proper travel i.e. Throttle fully depressed = injection pump throttle bottomed out.

---AutoMerged DoublePost---

Thanks for the info you posted here, going to make the throttle and tv cables install a whole lot easier on mine! I haven't decided yet wether to go the trouble you went to get the tach to work, but it looks like an aftermarket tach may be in the cards, great build anyways!
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  #387  
Old 06-13-2017, 10:40 PM
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Dont know why it wouldnt let me post outside your post, but anyway, thanks for the info!
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  #388  
Old 06-18-2017, 07:14 AM
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Quote:
Originally Posted by Hillbilly1 View Post
Dont know why it wouldnt let me post outside your post, but anyway, thanks for the info!
You are welcome.
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  #389  
Old 06-18-2017, 07:30 AM
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Lots of work, upgrades and perfecting things. York onboard air, oil pressure regulator, pretty paint, over the knuckle big brake 1 ton steering, hydroboost brakes, ARB lockers, shackle relocation, back to mechanical fan with custom shroud, rebuilt heads with port job, head studs. Also building engines 4 and 5 for another Cherokee.
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  #390  
Old 06-18-2017, 01:25 PM
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The throttle work is Epic! Great job, bravo.
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