Has anyone Plumbed your Generator and Big Engine Together

[Gary Hatt - Publisher BCM]

I had a thought when I was working in my generator compartment the other day. I thought that if I plumbed my generator coolant hoses into my big engine then it would allow me to pre-heat my big engine using my Kabota diesel generator engine. 

The Kabota engine should never have a problem starting in cold weather and I almost always start it first thing in the morning if I am boondocking anyway, but the big engine may work a bit harder when it drops down to no degrees outside if I ever travel in cold weather again.

Preheating the big engine makes it easier on the batteries, the starter and the engine itself and may even increase the life of the engine as warm oil flows better than cold oil.

Seems logical.  Has anyone done it...yet? 

[Nova Eona]

I haven't tried it, but I suspect you'd find that the engine's cooling system is so much larger that you'd end up with the worst of both worlds in cold temperatures - the generator would never get up to normal operating temp, while the main engine's temperature would not be significantly increased.

[Utahclaimjumper]

It's less complex to just use the generator to electrically preheat the majn engine as most do in the motorhome world..  It's coolant system can also heat the water in your water heater by wrapping the coolant lines around the heater,( also commonly done ).>>>Dan

[chessie4905]

Would be nice if a generator could make enough electricity to run a BLOCK HEATER to pre warm the engine. Maybe somebody makes one.🙄

[chessie4905]

Would be nice if a generator could make enough electricity to run a BLOCK HEATER to pre warm the engine. Maybe somebody makes one.🙄

[lostagain]

In cold weather, I have a Webasto that heats a loop that goes from it to one heater in the generator compartment, then an other heater in the other baggage tank, then to the defrosters, then back to the engine and preheats it. I usually start the genetator as soon as I get out of bed and switch the electric engine block heaters on. By the time we have had coffee and showers, etc, the bus and the Detroit are nice and warm, and I just show it the key and it starts on the first revolution.

[richard5933]

This is exactly how the generator in our 4106 was plumbed. The cooling system for the generator's Perkins connected to the main bus engine's plumbing. The Webasto also had a loop which went through the bus engine to preheat it. The only problem was trying to bleed the air out of the loop to/from the generator.

There was a 16" electric radiator fan mounted on the outside of the bus radiator which came on thermostatically. It was necessary when running the generator in summer weather, although it did take a long time to come on.

I'm not sure exactly where the connection points between the generator loop and the bus system were, but I remember one of them being brazed in somewhere between the 8V71's thermostat housing and the radiator.

I thought it was a nice system. If we ran the generator, it preheated the main engine. When we pulled into a boondocking site for the night, the generator was preheated. The Webasto warmed up the whole shebang. If my memory is correct, there was also a loop going through the water heater to make domestic hot water when either was running.

[Utahclaimjumper]

 Chessie,, most block heaters are only 1500 watts.. Most any generator worth hauling around would make that easily and then some..>>>Dan

[TomC]

I have a 1,500 watt block heater on my Kenworth with the Caterpillar 3406B. Since I had a gasoline generator (onan 6.5 commercial), When ever I was running the generator, the block heater was always on. Hence in 12,000 hours, never had to decarbon the engine. And in -5 degree weather it kept the engine sufficiently warm to start right up in the morning. No pumps, no plumbing, just a simple heating coil. Good Luck, TomC

[dtcerrato]

We have a Jeb 2000 watt Jimmyheat block heater on our IL671 DD. Gets it toasty warm in any cold & only uses less than a 3rd of our Onan's 6.5kw capacity... Replaced the element once in 40 years. Sits in a mid block water jacket and warms every thing including the oil in the pan. We went all the way and initially purchased the highest wattage offered for our application. Works great over the years.

[Timkar]

That's how mine is currently set up(gen and engine share radiator) I will be changing it back to independent radiator for genset as time permits. Last thing you want to do is blow a coolant line on engine side and not be able to run gen set to keep others comfortable inside the coach.

[luvrbus]

Keep those separated Gary your little Kubota has a higher PSI operating system than the main engine,plus if you have oil  or fuel getting into the system you don't want to tear into both engines to find the cause  BTDT on a friends GMC bus 

[Knuckles]

Like others i run my block heater(1500 watts) off my generator which is an onan6500watt and have never had any problems just start generator in the morning plug in block heater and by the time showers and breakfast are over the 871 will roar to life after hardly a revolution. This has always worked so good i never thought of doing it any other way even though many others do it differently

[luvrbus]

Gary's pre heat for his engine is tied into the Aqua Hot he doesn't need a block heater all he needs to do is flip a switch for 30 minuets

[Dreamscape]

I wouldn't recommend it. The DD 8v92 and genset that I purchased 3 years ago came from a donor Eagle that had the two tied together. The DD got hot, which had to be rebuilt. When I went to install the new to me genset, I found coolant in the oil. Pulled the genset Kubota head and found out it was cracked. So the DD killed the genset.

It's just not a good idea.