Making an Onan Quiet Generator Quieter!

[windymatt]

I must be the only person on the planet that has had no trouble with their 2800! Let me say a few GOOD things about them: they are compact, light, simple and quiet. Mine emits 60 dB @ 8’ from the side of the gen compartment at full load. At 50’ it’s the same level as ambient background noise. Inside the vehicle the dB level is 48 right over the insulated generator compartment. I think that the biggest problem is not the generator itself, but the lack of a properly constructed sound-attenuated generator enclosure in many of your rigs, and the lack of a secondary muffler. I have been in the off-grid solar field since ‘80, and have had to deal with about every type and make generator imaginable, but the biggest single factor in noise level is engine speed at full power. All the best ones used to be the ones that ran at 1800 RPM, though emissions requirements now make them very hard to find. A pity.

[nicaland]

Thank you windymatt for bringing this thread a bit back to reality. Theorizing about possible alternatives to the Onans, or any other non-inverter type gensets for that matter, that thousands, if not millions of RV owners have in their rigs is fun, to a point, but the fact is that many of us are either content with what we have, or simply can't afford to upgrade from what for many has been a reliable and relatively inexpensive source of AC power. What can be done for these units however is to use the Onan resonator (think of it as a glass-pack muffler) that you mention that significantly reduces exhaust noise, particularly to the external environment, in conjunction with a properly applied sound deadening mat that IdleUp described in the post that started this thread. This type of material will also reduce noise transmission to the external environment, but again, if studiously applied can make a very significant sound reduction to the interior to the RV as well.

There are several versions and manufacturers of this type of adhesive backed butyl rubber that is faced with aluminum foil, like the product that he used (Roadkill). Dynamat is another MFG that is very popular, and if you look around you can find many others, some a bit less expensive, but if you REALLY want to save money on this type of material, go to Home Depot and buy a roll ( or two or three or whatever) of U.Seal "Instant Waterproofing tape". $16.45 buys you a 25' of a 6" wide roll (12.5sf). This is exactly the same stuff as the premium priced brands, and if anything is easier to apply than struggling with a big sheet of this stuff. Believe me when I say that it really makes a big difference. I also use it to reduce road noise and improve speaker performance in cabinets and vehicle doors.

[IdleUp]

Originally Posted by Bud

I suppose a Statement should be made that onan can't miss.

At the next Big B Rally onans are donated that folks are going to toss out or HATE. Then some Big Gun Store donates some 12 gage pump and automatic shotguns. Of course money needs to be raised for a good cause, so there will be a fee to engage in the fun.

Frustrated onan and previous onan owners or people that just hate 2800/2500 onans can blast away with professional, welldone videos being made. These will the given to the news media to use, hopefully the nightly news and morning programs, wishful thinking. Ok, the all day news channels and rv world. All them ambassadors will add a video to their channels.....................

Bud

LOL Let me know the dates and location, I'll bring my trailer to get a load of those nasty Onan's cause I love'em!

It's a proven fact the Onan propane generator emits less carbon dioxide, less nitrogen oxide and up to 25% less “greenhouse gases” than a comparable gasoline and diesel sets.

Since a propane generator is so clean burning, the combustion chamber and valves remain almost carbon free. This clean burning also contributes little contamination of the engine oil.

Propane generators are the most reliable of all Onan generator sets and require the least amount of service and repair since there’s no liquid fuel, injectors, carburetor, fuel pump, nor common gasoline / ethanol fuel and moisture problems.

Enjoy - Mike

[Brad1998RD]

The Winnebago Rialta 1995-2005 uses both the Generac and Onan inverter generators.

[IdleUp]

Originally Posted by Brad1998RD

The Winnebago Rialta 1995-2005 uses both the Generac and Onan inverter generators.

Brad, Thanks for the reply and info - I was not aware that Onan made an inverter generator. It's a guess, but I would assume that since later coaches had an onboard inverter / chargers, they figured builders would not want to pay the extra cost for the feature. Does the generator lower its speed when not loaded or did it run at a constant speed.

Thanks Mike

[Brad1998RD]

Mike
Yes they both raise and lower their speeds as needed .
They are also alot quieter on their high speed than a standard generator.
Parts of course are getting harder to find to keep them running.
I would imagine that it was the installation of inverters that kept this the RV inverter generator from catching on. These were built for the Rialta as it has a very small space. 4-6" width left to right shorter than the Onan micro lite.

[IdleUp]

Thanks again for posting the information! Sounds like a great Type B & B+ generator!

Mike

[hbn7hj]

This is where my mind is going.

https://m.youtube.com/watch?v=kAKSGUDLg8A

I wouldn't start with an HF generator but I'd look at repackaging a Yamaha or Champion. Maybe there are other candidates. The Honda has a vertical cylinder on the engine and cannot be reduced in height.

I couldn't find verification that Onan had an inverter generator 20 years ago. Just have to take the poster's word for it.

I guess he has gone commercial but the website does not say what generator he is using. It says parts are available and parts are typically not available for Harbor Freight stuff.

http://www.rialtagenerators.com/

[IdleUp]

Here's a little "Sweetie" fom Powertech for Sprinter and Transit. It's diesel so can run off the main tank. Fit's nicely up against the rear bumper where the spare was located. An upgrade might give you another storage compartment where the Gen was located. It's about twice the weight of the Onan 2800, but in some applications you may be able to delete the propane tank to get the weight down.

Specifications

Power Output: 3,000W

Engine: Single Cylinder Diesel

Certification: CARB and EPA Certified TIER 4

Injection Type: Indirect Injection

Generator Type: Belt Driven Brush-less Generator

Controller: ECU Controller

Safety: shutdowns for high temp and low oil pressure

Output Voltage: 120VAC (240VAC Optional)

Amperage: 25A @120VAC (12.5A @ 240VAC)

Fuel Consumption: .22 GPH at full load and .10 GPH at half load

Weight: 260 lbs

https://www.powertechgenerators.com/...ter-van-rv-3kw

[Brad1998RD]

Not to mention the guy wants as much or more than Onan or Honda and thinks his is as good as a Honda or Onan. Can't possibly warranty them across the country. For what he is selling them for they have not been tested and certified for RV use either. So no way would I pay that kind of money for a home built unit that uses a dismantled and reassembled /reconfigured stand alone generator.

[Brad1998RD]

You're welcome
Would have been good in a B class.
The class C Rialta is really compact and works well in it. I wish they would have kept making the Onan.

[hbn7hj]

Originally Posted by Brad1998RD

So no way would I pay that kind of money for a home built unit that uses a dismantled and reassembled /reconfigured stand alone generator.

I would if I had a Rialta with a dead generator. When my Onan 2800 dies for the last time I will look into fitting an inverter generator in it's space. Harbor Freight would be my last choice but if it is the only one that fit I'd give it a shot. Wonder what his solution to the parts problem is.

I will look at Yamaha and Champion. Honda won't fit. The Onan engine is built by Subaru, I think. Maybe they make an inverter generator of 3kw.

A year or so ago Champion was gonna build a replacement for the Onan. Maybe it was wishful thinking on my part.

The electric start requirement limits the choices. A built in generator is so much more convenient.

[Bud]

Originally Posted by hbn7hj

I would if I had a Rialta with a dead generator. When my Onan 2800 dies for the last time I will look into fitting an inverter generator in it's space. Harbor Freight would be my last choice but if it is the only one that fit I'd give it a shot. Wonder what his solution to the parts problem is.

I will look at Yamaha and Champion. Honda won't fit. The Onan engine is built by Subaru, I think. Maybe they make an inverter generator of 3kw.

A year or so ago Champion was gonna build a replacement for the Onan. Maybe it was wishful thinking on my part.

The electric start requirement limits the choices. A built in generator is so much more convenient.

I'm wondering if only pull start could be used, then kill the engine from inside. Outside would be pull start and cutting the fuel off, running dry. There are folks here that could pull that off, not me.

[Brad1998RD]

I own a Rialta and I would not touch that especially at that price with a ten ft pole.

It's a bit different doing it yourself for yourself. But when you modify something and sell it for top dollar and as a business transaction it should be certified for that use.

If someday ours goes I will either modify an I gen or just buy the Onan microlite

[Brad1998RD]

There was a guy who did that in a rialta. He used a champion pull start 3,000 watt generator.
So yes it can work

[booster]

I just took quick look around and found this page that shows a bunch of the Generac mamuals for Rialta.


Generator


I didn't look at all the manuals, but the three random revisions I did look at all said that the generator had to be at a fixed governed speed to have the correct voltage and frequency, so not inverter style.



Are these really the units that were really used in the Rialtas as the page claims?

[hbn7hj]

Originally Posted by Brad1998RD

I own a Rialta and I would not touch that especially at that price with a ten ft pole.

What is the price?

[Brad1998RD]

Those are incorrect.
The model used in the Rialta is an inverter generator. They used the NP30G model inverter generator

[Brad1998RD]

Over $3,000.

[hbn7hj]

Originally Posted by Brad1998RD

Those are incorrect.
The model used in the Rialta is an inverter generator. They used the NP30G model inverter generator

The service manual says frequency is controlled by RPM. It is not an inverter generator.