[Doghouse]

I'm getting a fax from Detroit that shows the water flow and all the bypass lines, from what the guy told me today. Since I have the coolant line piped into the same inlet/outlet locations that my heatercore works from, water circulation through the heater core is instant due to a small 3/4 bypass that allows the heat to start working before the engine gets to full temp.
He didn't sound to sure of the info, so he's sending me an illustration.
Maybe my thermostat is shot,...but the truck runs great, and I can't wait to go out this time with my new aluminum oversized radiator.

My old radiator was 70% plugged up with dirt and oil, and my charge cooler was 50% plugged up. I didn't notice it because I started last December, but now that its hot,....this truck would go from 190 to 220 in seconds of starting even a small hill. Now with the new radiator, by the time the coolant comes through, the coolant tube is barely warm, and the top one is at 190.

[Rev.Vassago]

Originally Posted by Doghouse

Maybe my thermostat is shot,...but the truck runs great, and I can't wait to go out this time with my new aluminum oversized radiator.

That would be some real irony there, if the only reason your generator was getting such wonderful temps is because your thermostat on the truck was busted. :lol:

[Doghouse]

No kidding.
Today I replaced the Hi/Low range module on the side of my transmission. It was not always making the jump from lo to high, and it was leaking down my air tanks in 30 minutes. This is the new transmission I had put in a few months ago. The part was under the warranty, but I had to remove my floor again to get to it.
I'm going to wait til Monday to head out, so looks like I'll get some biking in and maybe a day at Busch Gardens.
My girl gave me a place in the Florida Ironman for my birthday (40th) I think she's trying to kill me :lol:
I have til November 1st 2008 to get prepared :cry: not much time, it's been 5 years since I've done that distance.

[Chiefwhatdahey]

Assuming you have a Detroit you will notice a tube running from the water pump to the radiator, that is a bypass tube, it is supposed to circulate coolant evenly until the thermostats open. There are two thermostats, they sit next to each other, one could be bad and the other good, the obvious thing to do is replace both of them, don't forget the seals in the bottom of the housing.

How's your setup working DH? What brand is the engine and generator?

[Doghouse]

The APU is from a now out of business place called A-Trans.
The only things left from the origional unit that I have not completly changed are the diesel engine (which has been replaced because the first one siezed up due to and oil pressure problem), and the generator head (which I have improved on because it ran too hot).
The rest I have changed to make it run better.

[Doghouse]

Right now it is working perfectly, but I've only tested it for 40 hrs,...this time when I go out will be the real test. Lets just say I don't have much faith in the unit, and I have a fully loaded Idleair card ready to go.

[NotSteve]

I was fully loaded last night.

[Doghouse]

Changes to the A-Trans genset:
1.Remove it from the box it came in (which was barely enough room to repair it in) and place it into a larger insulated box. It was so loud inside the box it came in that I absolutly had to put it into a biggr box and add 2" of heatsheild/sound deadening material. The unit is still a bit loud, but it's tolerable, and no where near a reefer unit, so I'm OK with that.

2.Eliminate the wire harness that had all the safety shut down sensors on it. This system did not work at all, it was supposed to protect the unit from low oil pressure, coolant temp,ect. The unit siezed the first engine because of low oil pressure, and the second engine over heated when the coolant pump stopped working. All this wire harness did was complicate a simple engine.

3.Remove the engine and gen head from the mounting plate and seperate the units onto a larger,stiffer plate with rubber isolators, and add an idler pully to make belt changing/adjusting easier.

4.Toss the old coolant pump,fuel pump,and starter. Add new 12v units and a more powerful starter.

5.Add a fan to the box to remove the hot air. Without the fan the box would get up to 170 degrees, and the genhead would go up as high as 220degrees. With the cooling fan the box stays around 130degrees and the genhead stays around 190degrees.

6.Wrap the exhaust to keep the heat out of the box.

7.Run the air intake up under the truck hood and add an intake silencer.

All this and I bought the unit for $3,500 a year ago. I could have just bought a small diesel engine and a genhead , put a belt between them and had way less problems. It seems though that it is running fine. I have 50 hrs trouble free running,and I'm headed out Monday.

There's a lot to be said for a dependable APU with a good warranty, but there's also a lot to be said for a unit that you can repair yourself. I still would have chosen to build the unit myself, and am putting a better one together to pop into the box,....when,...not if, but when the A-Trans unit finally calls it quits.

[Rev.Vassago]

I'm really beginning to wonder if I wouldn't be further ahead tearing this generator apart and swiping the generator head from it, then simply replace the engine with a water cooled unit.

Are all generator heads created equal?

[Doghouse]

Not all are created equal.
You need to find one with the lowest rpm to generate the power you need and then get a good 10 to 15hp diesel engine, find its sweet spot and then size the pulley's to make sure the engine doesn't over rev, or lug to spin the genhead at the right rpm.
Get a coolant pump, fuel pump, and it should all work.

It's easy to get a 3600rpm engine and a 3600rpm genhead, but thats a screamer. I would try to stay around 2400rpm with the engine and 2800rpm with the genhead. The unit would last a lot longer, run quieter, and be more fuel efficient.