Any comments on front mounting a generator like a diesel pusher?

belfert · November 28, 2009, 06:49:11 PM

Ruthi and her husband Ken are converting a 1998 Dina. I talked to Ken today on the phone and he has converted the area behind the front bumper into a slide out for an 8KW generator. Pretty much the same idea as a diesel pusher. (On a Dina the spare tire hangs there on a winch kinda like most minivans, SUVs, and pickups.)

I'm considering doing the same thing to free up luggage bay space. I would probably put my house batteries, inverter, and breaker panels where the generator is now if I moved the generator. (Batteries would be boxed and vented to prevent inverter damage.) I suppose I could also stick the batteries and such up front and not move the generator, but I'm more likely to need access to the electrical stuff on a regular basis.

Any reasons not to mount the generator up front like this? Would I need a grill for venting? I looked at photos of a lot of diesel pushers and almost none of them have grills up front. I don't know how they provide cooling air for the generator. I am pretty sure my front axle has enough capacity for this, but no idea if extra weight out front would affect ride.

I'm not sure my generator would even fit height wise. I couldn't find my tape measure earlier today. This would be a spring or summer project as it will be too cold until then to work on the bus.

luvrbus · November 28, 2009, 07:07:08 PM

Brian, people do installs that way on Eagles when they raise the floor to do a level driver access is made from doors on the side not from the front and then pull air from the bottom.

good luck

belfert · November 28, 2009, 07:14:17 PM

I'm not sure how I would install a side door to access the generator. One side has the main door of course, and the other side has the driver's heat and A/C in a box with a door.

When folks raise the driver's platform how do they typically deal with the extra steps required?

luvrbus · November 28, 2009, 07:19:43 PM

Some do in it in a straight run but most do a spiral

good luck

rv_safetyman · November 28, 2009, 07:25:49 PM

Brian, I have worked on several of the units you are talking about when I install my system. They are almost all Onan Quiet Box, with a PowerTech or two mixed in. They are enclosed units. I have manuals for both the PowerTech and Onan. The Onan is manual is out in the bus, but the PowerTech is on one of the computers. It has a side air inlet and a generator air exhaust on the bottom front and radiator air outlet on the rear bottom. I have always wondered if the hot air gets mixed with the fresh air when the coach is stationary. However, they seem to work just fine.

The weight of the generator will be hung out in front to the axle. Because of leverage, it will have more "impact" than just the weight in terms of loading the front axle. Several of the motorhomes have a big problem with overloading the front axles. One now produces a 16K front suspension system. Several coaches are close to the front axle weight limit when they leave the factory. I have read some forums where folks don't fill their fuel tanks (mounted in front) more than half.

As Clifford noted, some Eagle have done this, but only with a raised driver and also a mid door as I recall.

It all sounds good on paper, but I would want to start by having my bus weighed and then do some calculations on axle loading. It sounds like you would move some other heavy items up front (batteries) and that could make matters worse.

Jim

Van · November 28, 2009, 07:36:08 PM

Clifford, didn't Basil put one in the front ?

rv_safetyman · November 28, 2009, 07:42:37 PM

I forgot to make a comment about servicing the front generators. Most of the recent ones are on a powered slide out. They are pretty easy to service. Some are hard mounted and they can be a bear cat for anything beyond normal service. The commercial units have trap doors in the bottom that let you get to the fuel and oil filters and oil drain plug. The exhaust drops out the rear air exhaust opening.

Jim

luvrbus · November 28, 2009, 07:45:28 PM

To me with the front axle set back as far as is on a Dina it would be a easy install without many modifications.
The only concern I would have like Jim would be the weight on the front torque tubes the Dina's don't look that strong to me with the square tubes.

good luck

belfert · November 28, 2009, 07:56:23 PM

Quote from: rv_safetyman on November 28, 2009, 07:25:49 PM
It all sounds good on paper, but I would want to start by having my bus weighed and then do some calculations on axle loading. It sounds like you would move some other heavy items up front (batteries) and that could make matters worse.

I would only move the batteries up front if I did NOT move the generator to the front. If I move the generator to the front I will move the batteries to where the generator is currently mounted. The batteries are currently in the very back of the bus today.

The Dina front axle is rated for 12,000 lbs. I am at 9,900 lbs on the front axle today. I'm more worried about ride quality than overlaoding the axle.

My generator is the Powertech enclosed one. It is currently in the former condensor compartment so it has the whole side exposed to fresh air today. No heat issues per the temp gauge when stationay right now.

Len Silva · November 29, 2009, 05:31:54 AM

Blue Bird has done that for as long as I can remember.

Prather · November 29, 2009, 06:56:43 AM

Back in the late 90's when I was building my Eagle I talked to several "experts" on mounting a diesel generator up front. At that time I was warned that the weight ahead of my steer tires could have a adverse effect on steering. Also the weight could overload the front suspension under certian conditions. After I completed my conversion I noted that the front weight on my suspension was near the limit without the generator. Just something to consider.

Prather

belfert · November 29, 2009, 07:02:03 AM

Quote from: Len Silva on November 29, 2009, 05:31:54 AM
Blue Bird has done that for as long as I can remember.

So have all the class A manufacturers, but they design and engineer the coach from the ground up with the generator up front.

I don't want to go to all the work of doing this and find out it doesn't work since the bus wasn't engineered for this. I should be below my axle weight ratings by about 1,400 lbs after installing the generator up front since the generator weighs 515 lbs plus the weight of any steel.

I am a little worried about how having the driver and 8 passengers up front affects the front axle weights although not all of the weight should go to the front axle.

luvrbus · November 29, 2009, 07:06:20 AM

The difference between a Eagle and a Dina is the Dina is a shorter wheel base on a truck frame and you can adjust the front axle weight with the air tags same with Prevost and MCI
Basil has a 45 ft model 15 Eagle and they will carry more weight on the front axle than a model 10 or 05 so the generator is no problem for him.
You can also take weight off the front axle on a Eagle by adding more to the boggies not a big deal you can pickup some of the weight deference with aluminum wheels if you are running steel wheels

good luck

Busted Knuckle · November 29, 2009, 07:07:49 AM

Brian,
I honestly think you'll be OK doing this. But keep in mind that the actual weight is not you enemy here but the end weight. (in other worde think leverage!) I would just for safety sake double the weight of the generator when calculating. And yes you should still be OK!

BK

PS I have no actual knowledge on this, just thinking how I would do it. But as always YMMV!

Busted Knuckle · November 29, 2009, 07:12:02 AM

Clifford and I were posting at the same time a minute ago, and he brings up an excellent point!

By the way I can show you how to install airbags on the front of a Dina since "Dino" (the Dina leased to us) has them already! (installed by the previous owner for running "HEAVY" loads on rough roads in Mexico!)
FWIW

BK