Need Opinions on Older Onan Genset Location Please

[Dreamscape]

I have an older 12KW Onan Genset, air cooled model. Curently is located on the drivers side first bay. It is a real pain to work on etc.. There is a fan for cooling, I think it needs more air all the way around
I have thought of the location where the old bus AC was, next to the engine, passenger side. Probably mount it on a swing or slide out. Eagle 01, 8v71, 4speed manual.

What experience have you found to be the best location? I know suggestions will go both ways. Just looking for responses so I can make a qualified decision.

Thanks and Happy Trails,

Paul

Dreamscape

[captain ron]

I would think that would be too hot of an area because of engine heat. I have mine in the area where the ac condenser was MCI.
For now I just have a regular home type or utility generator. I don't use it much at all but when I do it works great, not too loud in the bus but probably annoying to any neighbors.

[Ace]

Paul talk to NCBOB who frequents this site often. He used to work for Onan and he actually rebuilt an Onan while staying in Arcadia. I'm sure he can help you with your cooling requirements!

Ace

[DrivingMissLazy]

I have an older 12KW Onan Genset, air cooled model. Curently is located on the drivers side first bay. It is a real pain to work on etc.. There is a fan for cooling, I think it needs more air all the way around
I have thought of the location where the old bus AC was, next to the engine, passenger side. Probably mount it on a swing or slide out. Eagle 01, 8v71, 4speed manual.

What experience have you found to be the best location? I know suggestions will go both ways. Just looking for responses so I can make a qualified decision.

Thanks and Happy Trails,

Paul

Dreamscape

That was where mine was mounted on my 80 Eagle. Actually two very heavy duty hinges that allowed it to pivot out about 120 degrees. When it was stored it actually rested on the bottom of the compartment witl little or no load on the hinges. Worked great.
Richard

[Dreamscape]

Thanks for your input guys!

Ace, I will try and contact NCBOB and get his input, THANKS.

Richard, The same place you had yours is what I am considering, THANKS.

Captain Ron, I am not sure where on your MCI you are talking about. The area I mentioned is where I think the AC for the passengers was at one time. I don't know about the heat as I would not be using it all the time. It just looks like it will get more air movement. It would be then located at the rear of the coach instead of under our couch in a somewhat closed up compartment.

Happy Trails,

Paul

Dreamscape

[TomC]

Personally would not mount it next to the engine.  Another 500lb or so behind the drivers.  Any compartment up front would be better for wieght distribution.  Why not make a hinged swing out where it is now?  Also-I have a 2cylinder version 6kw air cooled for stand by power, and it is a VERY noisy generator.  Wouldn't it be easier to sell this one and get one of the newer quiet water cooled gensets and keep your neighbors much more happy?  Besides, Onan isn't making those gensets anymore.  At least on my 6kw, it has Vacuflo cooling where the fan sucks the air over the engine then blows the hot air out of the cabinet.  Rather than the fan blowing the cooling air over the engine and having to duct out that big opening.  Good Luck, TomC

[Fredward]

My MC5 has an OLD air cooled Generac mounted on a swing out where the AC compressor was. It seems to work OK except I've had to replace the ignition coil. But you have to run your cabling to wherever your main disconnect/relay is. Also, that compartment is hot! Sitting right next to the engine and all the hot air from the radiators is blowing right down on the cooling air intake of the generator. I can't imagine that any air cooled engine is designed to be taking in 180+ degree cooling air. Probably not a good long term engine life scenario if you run the genny for roof top air when driving. If you only use the genny when the Detroit is shut down probably not an issue and there's lots of space there. Just be sure to mount it so it swings out 90 degrees so you can get at the Detroit's starter. I think I'd look real closely at keeping it up front where the condenser was.

[Ncbob]

Hi Paul,

Your generator has one of the two cooling configurations which Onan offered on their Air Cooled Gensets.  It is either Pressure Cooled (just a screen on the front of the engine fan) or Vacu-Flow cooled (a large squirrel cage fan enclosed in a directional housing similar to the smaller RV units).

In the case of the Pressure Cooled unit the air flows in the back of the generator end to cool the windings and in from the front of the engine to cool the cylinders and head and is exhausted out the duct on the starter side of the engine.
You can add a plenum to the discharge duct to direct the exhaust air down toward the road surface should you so desire.

Vacu-Flow discharge ducts are directional but they can be turned in any direction which best suits the installation.

It is vital that you know the intake air requirements for cooling in cu ft/min in order to maintain proper cooling for your application.  That info is available from the Service Manual or your Cummins/Onan Distributor.

You might wish to use  a roll out for this installation as changing the starter without one is a major undertaking.

Good Luck with your project.

NCbob

[Dreamscape]

Thank You for your responses!

I agree with the extra heat from the Detroit, I had not thought of that. And also the extra added weight in the rear, very good point Tom.
I did change the starter a year ago, and yes it was a pain in the a$$. That is one reason for this post. Better accessability for maintenance and repair. I am now thinking that building a slide out will be the best thing. Just have to use flexible exhaust  and allow for the electrical.
I do have a fan pulling air off the road, that is how it was hooked up when I bought the coach. I think I will take NCbob's suggestion and look into the proper cooling method.

All great information that I need to move forward with this.

Happy Trails,

Paul

Dreamscape

[John E. Smith]

I agree with the extra heat from the Detroit, I had not thought of that.

Paul, if you put a sheet metal heat shield in you won't have to worry about heat from the engine.  We have a couple who has an 01 Eagle with the generator mounted there (which is where the A/C condenser was mounted) and it works just fine.  However, we have another bus that comes here for service that has a 10 kw Kubota mounted in a roll-out frame in the first bay.  I really like servicing that gen set -- I can get to everything!

And also the extra added weight in the rear

Paul, with as much as the engine weighs and the fact that you are only adding about 200 lbs (in reality), you will never notice it.  The original A/C condenser and associated parts that you remove (or were removed) weight close to 350 lbs.  So I don't think that is really a consideration in this instance.

I do have a fan pulling air off the road, that is how it was hooked up when I bought the coach.

The best cooling method is actually the other way around... you want to pull the air through the side of the coach and exhaust out of the bottom.  This works well for two reasons... first, you don't have a stream of air coming out of the side of your coach -- right where people walk.  Secondly, any odors that are exhausted will go under the bus - where fellow campers won't smell them (as much, anyway).
Good luck on the new project!

[gus]

I' pulling out an Onan 2-cy air cooled 5.5kw and replacing it with a Honda 6kw liquid cooled enclosed one.

The Onan was so noisy and vibrated so much it drove me nuts and the heat out of it was unreal. I wrapped the whole exhaust system with EHP blankets which cut out most of the heat but I still couldn't live with the noise and vibration. It would run two 13.5 AC units much to my surprise! Parts are hard to find, I never could find new points.

[Dreamscape]

Does anyone have pictures of their slide out for their genset that they are willing to share with me? I have seen some pictures but they don't show much.

I am pretty good at fabricating, and will get the cam followers from McMaster-Carr. Is it a three rail slide so you can pull it out all the way? Or which method is best?

Happy Trails,

Paul

Dreamscape