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Discussion Starter #1
My question is so far in left field I'm not sure why anyone would have an answer to it but I thought I'd ask anyway just in case. In light of that I suppose speculation is just as welcome.

I have a 265kW caterpillar oil field generator end and I'm thinking of powering it from a GM 5.3 + 4L60E out of a wrecked truck. I'm not expecting or interested in getting 265kW out of it but just enough to power my house and workshop, which is <30kW (40HP electrical). I would need about 50 mechanical HP continuous to do that.

So I'm wondering if I would encounter overheating problems with the engine putting out 50HP continuously without 80mph of highway-speed air flowing thru the radiator.

If 50HP is no problem, then (just out of curiosity) at what point would it become a problem?
 

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I don't have any data to back this up; but if you build an efficient cooling system there is no reason it couldn't handle it's rated hp.
 

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‘01 Silverado 2500HD 8.1/Allison 5sp xcab long bed
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Agreed. If you confiscate the front end frame from the donor, you should be fine. Radiator, core support, and fan shroud provide significant airflow to take care of your needs.
 
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I'd also build a shroud around the fan(s).
 

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I don't have any data to back this up; but if you build an efficient cooling system there is no reason it couldn't handle it's rated hp.
It's rated HP? As in 310HP or whatever it is? That goes against my (perhaps mistaken) understanding of how passenger vehicle HP is rated VS how other engine HP is rated. My understanding is that the HP value given for passenger vehicles is a peak value, and the HP values given for engines spec'd for industrial & agricultural use (ex: tractors, generators, pumps, maybe 18-wheelers, etc) are continuous HP values. The 400HP caterpillar engine that is typically coupled to this generator is bigger than a whole Mustang, whose (comparatively) puny little engine might also be rated "400HP." The difference is that the caterpillar engine is designed to put out 400HP 24/7 from cradle to grave and the Mustang engine is designed to put out around 30-40HP while cruising down the highway, with brief peaks around 400HP when the driver gets an itch in his foot. My understanding is that ag/industrial motors have to be rated this way because anyone using them actually expects to be able to hit that number continuously and that automotive MFGs get away with publishing their ratings the way that they do, because it actually makes sense for the application. Cars only ever hit their peak HP, well, in peaks. In fact I can't think of a real life scenario where an automobile is expected to hit any number, much less its peak number, for any amount of time at all. It doesn't make sense to attach any continuous HP value to them. But if you hooked up a 5th wheel to a Mustang, sent it up a perpetual hill at whatever speed it takes to hit 400HP and set the cruise control, I don't think it would make it out of the county before the engine had an aneurysm.
 

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Ok, I answered the questions you asked.
You asked if the engine would overheat running at an rpm that would generate 50 hp.
I answered: not if you build an efficient cooling system.

You also asked it the cooling system required the inflow of driving at 80 mph.
I answered that with the proper cooling it would run at its rated hp without overheated. Trying to point out to you, that with an efficient cooling system you could run higher on the output curve.

Now, if you need more detail I'll try to help.

The approach you need to take, is where on the hp curve will the engine be for the rpm load you need for the generator; keeping in mind the rpms will not be constant and will/should change with load.
Then you can decide if the engine is big enough and if you have built sufficient cooling.
 

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Discussion Starter #7
Ok, I answered the questions you asked.
You asked if the engine would overheat running at an rpm that would generate 50 hp.
I answered: not if you build an efficient cooling system.

You also asked it the cooling system required the inflow of driving at 80 mph.
I answered that with the proper cooling it would run at its rated hp without overheated. Trying to point out to you, that with an efficient cooling system you could run higher on the output curve.
I think that by "if you build an efficient cooling system" you were saying more than what registered in my head. Now that I realized that, I'm thinking maybe use the radiator out of an 18 wheeler or similar (if it does overheat).


The approach you need to take, is where on the hp curve will the engine be for the rpm load you need for the generator; keeping in mind the rpms will not be constant and will/should change with load.
Then you can decide if the engine is big enough and if you have built sufficient cooling.
The generator needs to run 1800 rpm to make 60Hz. I like the 4L60E ratios. 1st gear (3.059:1) puts the engine running 5,500RPM and 4th gear (0.696:1) puts the engine running 1250RPM. If there is low load then the engine can run at just 50% above idle and if the load is really high then it can still meet the RPM demand without going over redline, and I believe 5500rpm is the peak on the HP chart too. So unless in 1st gear and running all-out, it won't be running in its most efficient power band but then in an automotive application it usually isn't either. Not sure if I should be concerned about that.
 

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just thinking here.... if the 4l60e electrical plug is disconnected it will default to 3rd gear. limp mode. sooo you could get rid of the computer, at least not need it and that part of the wiring harness.

what would 3rd gear get ya?

Al
 
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Discussion Starter #10
just thinking here.... if the 4l60e electrical plug is disconnected it will default to 3rd gear. limp mode. sooo you could get rid of the computer, at least not need it and that part of the wiring harness.

what would 3rd gear get ya?

Al
3rd is 1:1, so 1800 rpm. But I don't want to disconnect any plugs unless I have to. In fact I'm thinking my best option might be to leave everything in the truck. Just load the generator head in the bed, mount it down, disconnect the driveshaft from the rear diff and use that to turn the generator. Would need to run the driveshaft to a pillow block bearing with a pulley or sprocket under the truck and use a belt or chain up through a hole in the bed to another pulley or sprocket on the generator shaft.

If I got a 4wd donor truck then I could drive it to town like a front wheel drive car to fill up with gas instead of toting drums of gas back and forth with my tractor. Assuming it isn't wrecked too bad (or not at all). I don't have a donor truck yet.
 

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iv seen a couple car haulers built front wheel drive like that. getting rid of the rear driveshaft ment it could be very low to the ground. it was such a strange build but Iv actually seen more than one so this was not just a one off, they were all the same so it must have been the same company building them. they used the transfercase and the front half of the drivetrain, the rear half was more or less just a trailer. crazy.

good luck! I hope you keep us updated as I'm quite interested.

Al
 
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off topic but here is one of the ads I seen for the front wheel drive car hauler. a guy says it has the "tornado differential or tcase" I'm not familiar with whatever that means. it's still for sale! haha

 
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Discussion Starter #13
off topic but here is one of the ads I seen for the front wheel drive car hauler. a guy says it has the "tornado differential or tcase" I'm not familiar with whatever that means. it's still for sale! haha

I don't know how I feel about that one. One half of me thinks it's pretty clever and the other half wonders where the advantage is. When I pull the car hauler behind my truck I scrape on ground going into & out of gas stations with steep inclines, and on speed bumps. But with this I think it might be even worse because it can't flex in the middle without a ball hitch. This might be the ticket if you can't back up a trailer, but if you can back up a trailer then you'd probably find the car hauler truck less maneuverable than a truck + trailer. And now the truck is limited in what it can do. It might make sense if you move one car at a time for a living.

But it serves as good enough proof of concept for the idea of re-purposing the rear driveshaft and turning a 4wd truck into a fwd drive truck which was your point. Thanks for sharing that!
 

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no problem! I know, it's weird as hell and I completely agree.

Al
 

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My question is so far in left field I'm not sure why anyone would have an answer to it but I thought I'd ask anyway just in case. In light of that I suppose speculation is just as welcome.

I have a 265kW caterpillar oil field generator end and I'm thinking of powering it from a GM 5.3 + 4L60E out of a wrecked truck. I'm not expecting or interested in getting 265kW out of it but just enough to power my house and workshop, which is <30kW (40HP electrical). I would need about 50 mechanical HP continuous to do that.

So I'm wondering if I would encounter overheating problems with the engine putting out 50HP continuously without 80mph of highway-speed air flowing thru the radiator.

If 50HP is no problem, then (just out of curiosity) at what point would it become a problem?
I just bought a Generac genset, it is 3 phase, 100kw that is powered by a 350. It is set up to run on propane or natural gas, it is hooked direct with no transmission and has a governor which you failed to mention how you are going to regulate your power. I could tell you more but the radiator is rotted and I am trying to get a new one built, the issue is that Generac ran a shaft through the radiator with a very large fan to pull heat away from the unit. I had given your idea lots of thought and the issue of throttle control always was the stumbling point. If for some reason your load changes and you overaccelerate and over produce power you could burn up the items still online.

Newer or more modern appliances and equipment all run on circuit boards that are very sensitive to power changes. It isn't simple anymore. A new genset with auto start and auto switching will run around $12-13,000. Might be the cheapest route. I gave $4,000 for this one and now a radiator is going to be around $1,000, I also need a transformer to drop the output to closer to what I actually need around 32kw will be around $1,000 plus install. I wish I would of just bought a new genset with all the features for the $13,000.
 

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As for speed regulation, the factory cruise control would get it somewhat close. Be sure the torque converter is locked. Might not be in 2 nd.
A large generator may have more drag ~ cooling fan / windage than you expect compared to output
3 rd gear - direct - 1800 RPM
2 nd gear ~ 1.62 ? - just over 2900 RPM = add an oil cooler
If you go with the pillow block / chain drive- you can change your ratio.
Between 2000 and 2500 rpm might work well depending on power required.
 

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Engine speed is dictated by generator load, cruise control is operated by speed sensors.
I wouldn't re-engeneer the wheel, there are factory made products out there to governor speed, buy on of them.
 

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Engine speed is dictated by generator load, cruise control is operated by speed sensors.
I wouldn't re-engeneer the wheel, there are factory made products out there to governor speed, buy on of them.
Being 3 phase, it is an AC alternator. Designed for 1800 rpm it is a 4 pole. If 60 Hz output is required - speed must be correct. Most home generators are built with an - off the shelf - name brand engine - using a standard mechanical governor, the freq regulation is about 61.5 no load - 58.5 full load. The increased mass of the larger rotor/armature on this one should dampen speed changes. Cruise control under lighter loads should beat that. It`s just regulating tail shaft speed.
 

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As mentioned RPM must stay the same regardless of load. The cruise control will do that just fine. It is no different that pulling a heavy trailer up hill vs down hill, you want the speed to stay the same so the driveshaft RPM has to stay the same, The engine RPM will vary with load a bit. depending on the gear the trans is in and slippage of the converter. The transmission may decide it needs to down shift or up shift to handle the load, with a tunner you can play with those shift points and maybe even the converter lock up points.

Another option is to use a manual tranmission, then you will know what gear and thus rpm you will get and there will be no slip to mess with. Engine RPM will be a direct ratio to driveshaft RPM.
 
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