Cummins Onan generator exhaust modification

Anything is better than nothing. :)

Btw, all that I've read says the majority of the noise is mechanical for our propane Onans. So, you can insulate the compartment to help, and I found switching to a good synthetic helps. It only takes about 1 quart, so it's an easy change.

Thanks, for insulation any suggestions ?
After 10 hrs of run time I have switched to synthetic but the exhaust was so loud I didn't notice any difference.
Now all I ears is the cooling turbine and some mechanical noise. :)

thanks for including the youtube links! I agree - noticable improvement! I hate the noise of my Onan 2800 - might be worthwhile...! ST

I am having the same problem with my Bigfoot. I was considering putting on the "resonator" and re routing the exhaust. My first effort was enlarge the mounting holes slightly in the generator storage area and shift the unit 1/4" to prevent the exhaust tube from hitting the camper frame. I then made some vibration mounts out of high density foam, set the generator on those and reset the unit with large fender washers and rubber grommets. This has cut the vibration down to almost nothing. Could you please provide a photo of how you routed the exhaust under your unit and what you did for vibration on the exhaust tubing mounts.

Nice, the video really demonstrates the effect. We just bought our first camper with a generator and it is too loud for my tastes. I will be borrowing some of these ideas.

The "after" video sounded nice and smooth without all the rattle and mechanical noise. My camper is generator ready but I'm loving the storage space instead. I'll get a Honda in the future if I need too, but am thinking about solar instead as I never use the AC or microwave anyway...

Kudos to you for accomplishing this! :)

Dak

mylundboat wrote:
I am having the same problem with my Bigfoot. I was considering putting on the "resonator" and re routing the exhaust. My first effort was enlarge the mounting holes slightly in the generator storage area and shift the unit 1/4" to prevent the exhaust tube from hitting the camper frame. I then made some vibration mounts out of high density foam, set the generator on those and reset the unit with large fender washers and rubber grommets. This has cut the vibration down to almost nothing. Could you please provide a photo of how you routed the exhaust under your unit and what you did for vibration on the exhaust tubing mounts.

We are out camping, back on monday and I will post pictures from under the gen.

Steve

Pictures of how I routed the exhaust under the camper. I will work on vibrations next year. The noise was my concern for now. I spend 4 nights of dry camping at the british invasion car show in Stowe, Vermont, in September and I was so noisy that the camper beside me changed place a little farther in the field.
Youtube Sound 67dB 20 ft from camper
Youtube Sound 62 dB 20 ft from camper
Clear improvement.

20141006_131239 par steevesdbs, sur Flickr


20141006_131314 par steevesdbs, sur Flickr
Camper that was beside me

20140920_140828 par steevesdbs, sur Flickr
Part of the field, British invasion September 2014

20140920_092040 par steevesdbs, sur Flickr
Fryday night downtown Stowe, Vermont september 2014

20140919_190109 par steevesdbs, sur Flickr

It looks like you brazed the elbows to the resonator, then used clamps for the stock pieces. It sounds better in the video. Your comment that the neighbor's moved? Was that before or after the modification? Thanks again for the photos they are a big help.

I've been using the Onan resonator for 4 years. You will get even better improvement if you mount the genny brackets onto rubber bushings and also insulate the walls of the compartment with B liner sound deadening material. Alot of the noise you get from an Onan is vibration thru the genny mounting points and the compartment walls.