4.0l/AW4 XJ as a AC generator?

[woody]

:dunno: if this should go here in "Other Tech" or over in "Mod Tech"

I've decided to retire my beater trail rig. It's axle-less & on stands now, but it runs well & could drive if those parts were reinstalled.

I'd sort of like to keep the engine/trans as a 'spare', since despite the +200k, they always ran really well. Leaving them in the carcass allows them to be run once in awhile... vs the PITA of pulling them out & having to seal/store them somewhere.

One of the ways I could "almost" justify keeping it around, would be to add a generator to it... something that could power a house during outages.

I'm assuming it's fairly straight forward to run a belt or chain drive off the t-case output up through the floor to a generator mounted in the cargo area? The AW4 has a manual TC lockup switch, so in 3rd/locked, it's true 1:1 drive. It's also switched to allow holding any gear 1-4.

Another brainstorm would be to install any old D35/8.25 out back and a front 30, steering links & driveshaft, That way (in 4WD) it could move around under it's own power :laugh3: or since it's camouflaged anyway, drag it out past the treeline & "plant" it

The biggest issue I see is keeping it cool during extended runs. Our power outages are equally likely during the summer "hurricane" months as they are in the winter "ice-storm" months. I've divorced the tranny fluid from the radiator, and would convert it to open cooling. I'd probably lose the fan clutch, and put a solid spacer there, so it's running full-time. The exhaust would be plumbed up high & attach a rain-flap, or get a long run of water pipe & plumb it w-a-y over so it's exhausting towards the neighbor's house.

Setting aside the whole 'hillbilly' aspect of this idea... what am I missing?

Parts Needed: (?)
Generator
roll of HD ROMEX
Breaker panel & breakers
120v & 240v outlets
Transfer switch for the house

Misc XJ parts:
HD 'open cooling' Modine Radiator
fan clutch spacer
low oil pressure cutoff switch
hi coolant temp cutoff switch
misc tailpipe tubing & flap
Homebrew SYE and pulley/belt or sprocket/chain

TIA

Woody

 

[frsno jeeper]

I think i heard about a guy doing this before.
It was on that jeff foxworthy DVD.The one that starts with "You might be a redneck"

 

[w_howey]

Here at HIXJA World Headquarters we have been pondering the same types of questions.

I remember seeing a 4.2l AMC motor doing duty as a water pump when I was working somewhere.

Anyway, why not use a PTO driven Gen-Set? They have a PTO shaft input, I believe they are geared for 600rpm input or less. Some even come with the necessary gear needed to mount it on a categorey 1, 3-point hitch.

Just take the rear output off the t-case, get it re-cut to accept a standard PTO shaft, and mount the Gen-Set low enough to keep the PTO shaft angle low. Then leave axles in it. Pop it into 4wd, move it on Fwd, drop it into 2wd, your stationary and your in business.

Here ya go....
Genset Link

 

[Matthew Currie]

You will need to rig up a governor for the engine, but this shouldn't be too complicated. A belt-driven flyball governor should be possible, and not too expensive. Without a governor, the engine speed, and consequent voltage, will vary too much with changing loads. A certain amount of fluctuation is all right, and you can balance the load by switching lights in the house on and off, but you need at least a rudimentary governor.

Running the generator off the rear output of the TC and connecting the front to a working axle should work for making it mobile. I think a good solid fan might be all you'd need for cooling. Remember that the engine will run better and cooler at a constant midrange speed than it does at idle. Most industrial engines don't need that much special treatment for cooling.

However, I should point out that the XJ is overpowered for an auxiliary generator, and may not be very efficient. My old 29-horse Ford tractor is more than adequate to run a 30-amp three-phase generator, which will run everything in my house handily except the hot water heater.

I saw an amusing variant of this idea at a local garage that specializes in Subarus. They simply took the hood off an old Subie, fabricated a bracket on top of the fenders, and mounted the generator on that. The generator was belt driven off the front of the engine. The car remained otherwise unmodified, and still mobile, though visibility was obviously a bit compromised.

I think if you can find an appropriate generator, it might be worth doing, because even if it turns out not to be the very best setup, it should work, and if a better power source comes along you can always change it later.

 

[BrettM]

what about a big alternator and a big invertor? would it provide enough power for your needs?

 

[w_howey]

You will need to rig up a governor for the engine, but this shouldn't be too complicated. A belt-driven flyball governor should be possible, and not too expensive. Without a governor, the engine speed, and consequent voltage, will vary too much with changing loads. A certain amount of fluctuation is all right, and you can balance the load by switching lights in the house on and off, but you need at least a rudimentary governor.

Running the generator off the rear output of the TC and connecting the front to a working axle should work for making it mobile. I think a good solid fan might be all you'd need for cooling. Remember that the engine will run better and cooler at a constant midrange speed than it does at idle. Most industrial engines don't need that much special treatment for cooling.

However, I should point out that the XJ is overpowered for an auxiliary generator, and may not be very efficient. My old 29-horse Ford tractor is more than adequate to run a 30-amp three-phase generator, which will run everything in my house handily except the hot water heater.

I saw an amusing variant of this idea at a local garage that specializes in Subarus. They simply took the hood off an old Subie, fabricated a bracket on top of the fenders, and mounted the generator on that. The generator was belt driven off the front of the engine. The car remained otherwise unmodified, and still mobile, though visibility was obviously a bit compromised.

I think if you can find an appropriate generator, it might be worth doing, because even if it turns out not to be the very best setup, it should work, and if a better power source comes along you can always change it later.

Matt,

Actually the governor doesn't even need to be that complicated. You talk about your tractor. It has a simple lever style throttle. Simply rig a manual-style choke cable up to the throttle, set it using a tach, and you are good to go.

 

[Root Moose]

Are you planning on only using this when the power is out for a few hours at a time? That is, not for multi-day use?

Because if you are, you better have a fuel tanker on site to keep it running.

I find the 4.0 quite thirsty. I can't imagine using it in this fashion unless you are planning on powering 10-20 kVA - and then diesel is a lot more cost effective.

Hell, locally you get can get 5-10 kVA Honda or Onan gensets for ~$1000-$1500 (used)...by the time you factor fuel and set up costs....

Just a thought, don't mean to be a spoiler.

r@m

 

[Storydude]

Ask Zmoz....He's the Powerbaron. Of course, his generators only run on a magic concoction of Krispy Kreme, and Kryptonite...

On topic, HF sells a nice 5 Kw head for pretty cheap...

 

[Matthew Currie]

Matt,

Actually the governor doesn't even need to be that complicated. You talk about your tractor. It has a simple lever style throttle. Simply rig a manual-style choke cable up to the throttle, set it using a tach, and you are good to go.

Sorry, not so. The tractor has a built-in governor, as do most tractors, lawnmowers and other industrial power plants. The throttle does not operate directly on the carburetor, but on the tension spring of the governor. In this case ('54 Ford NAA) it's a mechanical governor run off the timing gears. On many small aircooled engines, it's a vane pushed by the airflow from the fan. You may not always see it but it's there. Tractors and their implements are meant to run at a constant speed, and it would be surprising to see a serious tractor without a governor.

The load on an alternator used for backup power will fluctuate considerably, and even with a governor, the lag will cause some fluctuation and surges, so you may have to set a median speed and balance the load with house lights to keep it in range. Without it I think you'd have more serious problems, and end up burning out motors from undervoltage and electronics from overvoltage.

P.s. following up on root moose's suggestion, you might also look into used welder-generators. You can get a pretty good hit of auxiliary power, and a nice welder too.

 

[w_howey]

Sorry, not so. The tractor has a built-in governor, as do most tractors, lawnmowers and other industrial power plants. The throttle does not operate directly on the carburetor, but on the tension spring of the governor. In this case ('54 Ford NAA) it's a mechanical governor run off the timing gears. On many small aircooled engines, it's a vane pushed by the airflow from the fan. You may not always see it but it's there. Tractors and their implements are meant to run at a constant speed, and it would be surprising to see a serious tractor without a governor.

The load on an alternator used for backup power will fluctuate considerably, and even with a governor, the lag will cause some fluctuation and surges, so you may have to set a median speed and balance the load with house lights to keep it in range. Without it I think you'd have more serious problems, and end up burning out motors from undervoltage and electronics from overvoltage.

P.s. following up on root moose's suggestion, you might also look into used welder-generators. You can get a pretty good hit of auxiliary power, and a nice welder too.

Yea, I realized that about 15 minutes after I typed that... One of those blonde moments, where something seems so clear, but is completely wrong.

 

[woody]

Thanks for the input...

I figured a hand-throttle (or the old "coins 'tween the throttle stop" would get it)

Believe me, if a Miller Bobcat 225 or 250 - Especially the diesel powered- was in my range, this post would never have come up. 10kw + weld all day...what's not to like?

Most of the time, the power is only out for a few hours... others, like after hurricanes, we've gone several days. Presently we are 100% electric heat/A-C, so keeping it "lit," and the fridge cold are the two main priorities. I should have backup wood heat before next cold season.

The alternator-invertor ideal is valid... on that track, I already have a 150a alt. in my daily-driven XJ, plus one deep-cycle battery.

Still worth doing some more research... but I figure IF I re-hung axles under the beater , I could sell it for enough to get another deep-cyc. battery and a big invertor... OR a stand-alone generator.

 

[RichP]

I've thought about this too, tired of having to clean the freezer out after a 3 day power outage which seem to be alot more common in the last 5 years than they have been in the last 20. I think though that I would want it setup like the navy and the telcos do it, DC generators to batterys and then to an dc to ac converter, I think that would cover changing loads as things cycled on and off. Also don't forget the isolator switch on the main, that adds another $60-$100 to the price...
Personally I would want the motor on a stand, we had a setup like that in metal shop when I was in highschool, Ford 390 mounted with a radiator in front and a control panel in the back plus a 5 gallon blitz mounted in a holder bolted to the frame.

 

[Matthew Currie]

I've thought about this too, tired of having to clean the freezer out after a 3 day power outage which seem to be alot more common in the last 5 years than they have been in the last 20. I think though that I would want it setup like the navy and the telcos do it, DC generators to batterys and then to an dc to ac converter, I think that would cover changing loads as things cycled on and off. Also don't forget the isolator switch on the main, that adds another $60-$100 to the price...
Personally I would want the motor on a stand, we had a setup like that in metal shop when I was in highschool, Ford 390 mounted with a radiator in front and a control panel in the back plus a 5 gallon blitz mounted in a holder bolted to the frame.

I think that Woody's situation would make inverters a problem if he wants to run heat. I'm assuming here that it's a heat pump rather than just resistance heat. If it's resistance heat, he might as well forget it unless he scores a mighty big generator. If he intends to run a heat pump as well as other appliances, he's still going to need a pretty hefty 220 volt setup. In his place I think I'd consider putting some of the money into a good wood stove, and look at smaller generators. If you have a few lights, the refrigerator and freezer, and running water, you're pretty well set for even an extended power failure as long as you don't freeze. 30 amps at 220 is more than enough for that. With my 30 amp setup we get lights, pump, oil burner, etc. with no worries, and I can even use the electric oven with a little planning. The only thing we shut down is the water heater.

As far as the freezer is concerned, remember that a freezer uses very little power. You can keep a freezer going with a little 10-amp portable generator. You don't need to hard wire something like that. If the alternative is to lose a freezer full of steaks, that generator will pay for itself the first time you use it.