1964 wagoneer... om617 diesel

[230ohc]

Thanks for that info, I've got an ax15, Dana 300 I'm planning to stuff into there just got some shifter fabbed up for the tcase. Working on getting an external slave setup.[youtube]https://youtu.be/QJRO8qrBeK8[/youtube]

[tgreese]

There has to be a better way to analyze this.

Do you know what the torque curve is for this engine? Horsepower is torque times RPM. AS the engine turns faster, the power output increases according to the torque curve. You should be able to figure out how much HP you're making at each speed under varying conditions. Conditions will vary based on the hill, and the speed. Wind resistance goes like the square of the speed, so on level ground it takes twice as much power to go 40% faster, or 4x the power to go twice as fast.

I would suggest that it may not matter what gears you have, if your torque curve is not flat-ish out to the RPMs you want. We see this with the CJ and the original 4-cylinder engine. Most of these came with 5.38 gears, and you can't extract much additional speed by changing the axle ratio. These Jeeps feel strong at low speed, since they have a very long stroke and the torque comes on strong off idle. However, they fall flat at highway speed, because torque is falling off with increased RPM and the wind resistance is increasing faster than the engine speed. They are typically slower with different gears.

Jeep offered optional 4.27 gears in the 60s, and that provided a bit more highway speed. Of course, any hill or headwind could make the Jeep slower than the 5.38s would be in those conditions. The 225 V6 was a better solution.

[230ohc]

So I had a Toyota pick up, 4 cylinder. 5 speed 4x4.

With stock tires it had ample drivability
uphill (highway 88), 4.10 gears. I put 32" tires on it and I could not keep it in gear rev out in 3rd and bog out in 4th. Always shifting. I attribute that to gears not being low enough for the larger tires with the lower output of the 4 cylinder.

I don't know what h.p. and torque are for this engine but I know it's low like the lowest option even for this series of engine as the om617.950 is the first turbo model of the series, some of the later ones made more but not this one.

I've had issues with this setup going up the same
hills (hwy 88) however in the end I figured out that with stock tires 29" and 3.73 gears it was not a problem so long as I drove at night not to piss off the locals going 35-40 miles an hour in 3rd gear. There is power there but I'm now running bigger tires and I'm starting to lose power. I figure I can keep the top speed with overdrive and keep the hill climbing power with some larger(lower) gears.

I don't have too many options with the Dana 27 up front, afaik 3.73 4.88 5.38 are my only options I've got 3.73 and I don't want to run 5.38 so 4.88 seems to be what I'm going to go for. If it's too low I'll bump up tire size.

So any how I'm going to likely do the ax15/dana300 first and see how it goes I'm hoping that the close ratio 5 speed shift times may save allot of hassle,
but I would like an external slave setup before hand.

[230ohc]

H.p. 110
Torque 150 ish

[230ohc]

Is elite a good ring and pinion manufacturer, or should I stick with Dana?

[230ohc]

Been running numbers and it'd be ok with same top speed if I had more power on demand. But if I keep 3.73 top speed will be 96. I think that's to fast for drum brakes

DSC_1799~3.JPG

[Yeller]

Having driven some of those in the car they came in, I think you‘ll be much happier with the 4.88’s and the AX15. They need some rpm to make the torque and HP you need. The gear splits are much better too which will improve the driving experience for you and those around you lol.

[tgreese]

Just a comment - re your Toyota, seems very likely there's more to that than the diameter change. There will be more rolling resistance (small effect) and a larger frontal area (not a small affect, I would reckon.) Wind resistance is a mighty barrier, and the bigger tires increase your frontal area quite a lot. They also will disrupt the air flow down the sides of the truck. Both disturbed flow (complicated but organized) and turbulence (chaotic) take energy to overcome.

May be obvious, but this will be a big difference between your Wagoneer and the donor car too. Can't expect to achieve the speeds that the car could, and your calculated maximums after the equipment change may be unattainable.

Not being negative - just thinking that there must be some data points you could put in from simple experiments, like top speed in each gear up different hills. Just what I would do, but I have the background and experience to at least make a WAG about the effects of hills and wind. Excel might help, plus some BOTECs.

I'd also mention - similar questions come up a lot on these forums. Explanation plus a thorough treatment of a real-world example might be a popular post. Maybe there's something helpful in the publication record, in automotive design journals or texts.

[230ohc]

Having driven some of those in the car they came in, I think you‘ll be much happier with the 4.88’s and the AX15. They need some rpm to make the torque and HP you need. The gear splits are much better too which will improve the driving experience for you and those around you lol.

That's about what I've been thinking. I've got a cj front axle laying around with 4.88 Dana 27 that I can rob from. Just need to pick up a rear set up.

Ordered external slave setup for the AX15, so hopefully get installed around the end of the month.

[230ohc]

Mr. Reese. Thank you for the input, that's alot to consider.

Aside from wind resistance, which here in Oklahoma is fairly extreme at times. My bench mark for performance goal was simply to achieve ability to travel uphill on hwy 88. Which is in California, so the real world data I've collected is from that hill. The particular stretch I'm familiar with is about 80 miles with an elevation change of about 100 feet per mile.
Not much wind to speak of unless it's blizzard at which point the pass is usually closed.

This benchmark is relatively useful let's say considering traveling on relatively flat ground with high wind, so given the data I've collected and goals I've put forward in going the proposed setup will achieve the rpm where I feel the most power can be made is around 3k and can push past that point a bit but not much.

It is also my understanding that differential gears can make it break your transmission. So I'm hoping to take some load off the weaker ax15 by allowing the lower geared axle to do the brunt of the work.

I'm sure there is some relevant information you could add given your expertise, the parameters have been layed out.

[230ohc]

Okc

Cool, I’m 30 minutes NE of Tulsa

Do you ever go to Davis, South of OKC on 35.?
There is a park there I would love to take my Jeep to.
Cross bar ranch.

[Yeller]

Okc

Cool, I’m 30 minutes NE of Tulsa

Do you ever go to Davis, South of OKC on 35.?
There is a park there I would love to take my Jeep to.
Cross bar ranch.

I do and have been there a couple of times. There is a lot of varied terrain from super easy, almost fields, to some really narrow, extremely difficult hill climbs.

That is one thing Oklahoma is short on is wheeling opportunities, fair amount of really dumb hard stuff but not much just go and and explore. And just about all of it, if you didn’t pay someone you are trespassing unless it is a forest service road in our very limited (and limiting) National Forest areas. Texas is even worse…. Arkansas has much more opportunity, much larger National Forests, and 1000’s of miles of minimally maintained roads to explore.

AX15’s are actually fairly robust. They hold up well to moderate v8 power and work well with the Cummins R2.8 as well. They aren’t an NP435 or an NV4500 but on the opposite side they aren’t a T150 either. I was seriously contemplating putting one behind a 5.3 LS, ran the numbers a bunch and talked to a lot of folks running them. Then I found a cheap 6.0 and 4L80E….. lol

[230ohc]

Ls power must be nice,
the last U-Haul I took out here recently was GMC 3500 srw. Though it was governed at 75 it sure has plenty of power to move the 10 foot box halfway filled up with parts and an 18 foot trailer with my wagon on it.

I didn't much like the two thousand mile trip at 8 miles per gallon however.

[230ohc]

So purchasing a twin stick setup for the Dana 300 had been on mind for a few years until now that I've made my own at no cost, soo.... I kinda splurged on a few items.

I ordered the external slave setup for the ax15,
I ordered the 4.88 rear setup. Elite I hope it's good ,
And.... Hx30.
I think I'm light of all this I will need a pump too.

[tgreese]

...
I'm sure there is some relevant information you could add given your expertise, the parameters have been layed out.

Hmm. Been thinking about what one might do, off and on. First thing I'd want is to make a spread sheet of my engine's power output. If you have the torque curve, you can calculate the HP. Then I'd look for a couple or few of fixed points that I could add, maybe top speed on a long gradual uphill? Or more than one hill? Top speed on level ground in still air would be a start. Beyond that I'm not sure. A car maker would have a dynamometer and wind tunnel where they could test both output under load and drag.

Sorry, it's not something I can throw together in a few minutes. I'm not sure it's possible to get sensible results. Maybe... likely better than guessing. I was kinda hoping to encourage you to explore the problem more quantitatively.

[230ohc]

Base h.p. is 110
torque is 150
Diff gears 3.73:1
Tire size 235-85/16
Top speed in 4th gear at 1:1 is 70 mph
Top speed in 3rd uphill @ 1.69:1 is 40 mph


I don't really see any reason not to, if it was dedicated trail rig I'd probably leave it the way it is(<-total lie), but I'd like to have a kind of dual purpose vehicle.

[Yeller]

If you use Oklahoma Highway 88 as a bench mark you’ll be a super star. Bet it doesn’t change 20’ in elevation over its 26 mile length

I really believe your headed down the right path.

[BaldBeardedBastard]

Just to toss in my two cents- I designed around a cruise speed of 65-68 mph to land at peak torque for my diesel. Right now I am geared too tall with the factory 3.31s- changing to 3.73s soonish.

I have some data I can pull from a short(1-2 mile) climb I had this past weekend, but I have 310ft-lbs, so it may not be apples to apples.

Your om617 also has peak torque around 2200-2400 according to Google, so you may need shorter gearing to get the RPMs up.

Sent from my Pixel 6 Pro using Tapatalk

[230ohc]

Ok, so at peak torque in 5th grear with 4.88 is 58.92 mph,that's pretty sweet.

The numbers are much more promising (faster) with 3.73 but, I've never once got drowsy behind the wheel of this thing if that tells you anything. I don't know if faster is the answer. I guess it's free to try once the ax15 is in but I'd like to get as much accomplished while it's under the knife.

[230ohc]

Out with the old