Internal v. External Generator

[straygoose]

Just bought an '87 Gran Ville, moving from an older Ford Class B, and so far everything is as I hoped it would be. I have wanted a Toyota rig for a long time and I found one with low miles, no leaks, and other than a minor brake problem, in real nice mechanical and cosmetic shape.

Unfortunately, the unit came without an internal generator. From previous experience with my Intervec Falcon, I know that I need generator power, since I spend months and months on the road working and living out of the RV. I was able to get away with carrying one of those small 900w Chinese jobs from Harbor Freight, which would power my laptop, fans on the rooftop AC, and things like a coffeemaker. It was obviously not enough to power the compressor in the rooftop AC or the microwave, but I sometimes would stay in a campground if I needed the extra power. I want to eliminate the campground part, or at least minimize it.

BTW, with all the discussion on the forum about that little 2-cycle gennie, all I can say is she works great for what I use her for and is very efficient. Not a bad way to spend a hundred bucks. Always starts first or second pull and once she warms up, is kinda like the mouse that roared (they are a little loud).

Anyway, back to the question. At some point in the next month I am going to be investing in a generator setup and while my preference is for an internal unit, the option of mounting an external on the back rack is also in play. I have the vented compartment where the optional gen was supposed to go,just behind the drivers side door. It even has the hole in the back of the box where the harness would go through to the coach. While it's a good spot to carry the loud mouse and a five gallon gas tank, I would obviously like to use this space for what it was intended to be used for.

New internal units are expensive so I would be looking for a good used unit with low hours, probably 3Kw. I have a tech in So. TX where I live that can install it along with all the electricals. This is the way I want to go.

OTOH, the external would probably be cheaper, and I could go with a new generator, but there are problems with that approach for me:

While I do have a sturdy rack that would probably hold whatever size gen I wanted to have there is the issue of security. I spend almost eight months a year working on the road and I spend a lot of that time in the wilds of the urban America. It is not unusual for me to pull into a parking lot in or on the outskirts of a big city, and set up shop (discreetly, of course) for a few days at a time. Most times the neighborhoods are good, but sometimes the job takes me to places where I have to be very aware of what is going on around me and take steps to secure myself and my gear. Anyone who has spent a lot of time in inner cities will know what I mean.

In a nutshell, if I use an external, I need to build a vault for it. A vented, possibly fan-cooled, heavy duty box that the generator can sit in and run, and will be insulated well enough that it would be hard to hear, and even harder to steal. I have even considered putting the damn thing on the roof, but that won't work for a lot of reasons.

I really do not like this option, but it may be the most cost-effective way to go. There is also the problem of putting extra weight on the back of the rig. As you all know, these little beasts can't take much more than they already carry, and that's especially true on their rear ends. The internal option would have the weight more or less centered over the frame, which is probably best.

Has anyone built an external rig like this? Did it work? Were there overheating/ventilation problems? Security issues? Weight distribution problems?

These are the things I need to know before I decide which way to go. I know folks here have solved this problem both ways, so I'm looking to tap into all that accumulated knowledge.

Thanks in advance for any ideas you may have. If there's any additional info you need from me, just ask.

Goose

Edited October 24, 2012 by straygoose

[WME]

Internal ONAN micro 2800, also available as an camper external...big$$$$$

Get 9000 BTU micro A/C and a Honda 2000 for external mount.

Box for Honda http://www.kshmarine...nerator_box.htm

[straygoose]

That box is just what I had in mind for an external. Let me ask you this: Is it possible to mount that Honda where the internal gennie is supposed to go?

I'm not with the RV right now, so I can't take measurements, but I have a feeling that Honda could fit in there. Then it would just be a matter of hooking it into the gas tank, harnessing it into the RV, and installing a remote start. Oh, and running an exhaust system.

[linda s]

That box is just what I had in mind for an external. Let me ask you this: Is it possible to mount that Honda where the internal gennie is supposed to go?

I'm not with the RV right now, so I can't take measurements, but I have a feeling that Honda could fit in there. Then it would just be a matter of hooking it into the gas tank, harnessing it into the RV, and installing a remote start. Oh, and running an exhaust system.

If it will roll in and out freely you could build heavy duty roll out shelves into the generator compartment. When you need to use it roll it out. It needs to have more ventilation than the compartment can give it and outlet for exhaust. I did see one built into a truck camper on another site but don't know where the link is. They added a fan and some kind of exhaust system.

Linda S

[straygoose]

OK...some internal gennies are on slides for maintenance, so that makes sense, but I need something that can run inside that compartment. I don't want that gen hanging out when I'm parked on a side street at 2am in South Philly.

[Dolphinite no longer here]

Straygoose,

Here's a link to a site featuring the installation of a portable Honda generator in the original generator compartment of a truck camper. This is an excellent installation by a very competent person. He addresses the major drawbacks to an installation of this type:

1 .Overheating of the portable generator and possible fire

2. Elimination of the original fuel tank and installation of a better one

3. Rerouting the exhaust

4. Modifying the original compartment to accept the portable generator

5. Developing a hold-down system to keep the generator from moving around

6. Installing better locks on the compartment door

One note here; this guy is very competent and not doing at least what he did could lead to a fatal fire or explosion, injuring the occupants of the Toyhome and anybody in the surrounding area, ie: other campers near you in the campground or on the street. Also, an installation of this type will void your Honda warranty

John

http://fubigoil.net/?s=honda+generator+install

[straygoose]

Explosions? Mayhem? Common household items as incendiary devices? I'm there dude!

Seriously, thanks for the link. This is kind of what I am looking to do. I don't want to spend 3K on an Onan, no matter how much I like them. Hopefully in a month or so I will be able to report that this got done.

Quick update: This looks more complicated and dangerous than I thought. Fun, but dangerous. I think I need another solution. Looks like I'm back to square one.

Edited October 24, 2012 by straygoose

[Maineah]

There are many issues with non RV generators. The RV units exhaust out the bottom both hot air and engine exhaust they have their own fuel pump not gravity feed drawing fuel from the truck tank. Cooling is a problem because the portable units need air from 360 degrees to cool both the engine and the generator it's self where the RV units force the air through every thing. I know a portable unit would be a hassle but if you don't want to spend the big bucks the only real way is to put it on the ground. If you go to Cummings directly you probably can beat the cost down on an Onan and come close to a 3KW Honda price. Chain it to your rear wheels get a big dog but putting it in a compartment is asking for trouble.

[straygoose]

There are many issues with non RV generators. The RV units exhaust out the bottom both hot air and engine exhaust they have their own fuel pump not gravity feed drawing fuel from the truck tank. Cooling is a problem because the portable units need air from 360 degrees to cool both the engine and the generator it's self where the RV units force the air through every thing. I know a portable unit would be a hassle but if you don't want to spend the big bucks the only real way is to put it on the ground. If you go to Cummings directly you probably can beat the cost down on an Onan and come close to a 3KW Honda price. Chain it to your rear wheels get a big dog but putting it in a compartment is asking for trouble.

You are probably right but It looks for all the world like this compartment was designed to hold an Onan 3Kw. It is identical to several other Toyotas I have looked at that have generators. All it needs is to have one installed.

She is in the shop getting her brakes done, but I should have her out this afternoon. Let me get her back and get some pics posted. It may be a day or two, as I have to make a 700 mile drive to KY, but I'll get them up as soon as I can.

[Totem]

love that honda link John! is that thing mounted in a truck camper? I can see accordion stairs off the back.

[Derek up North]

love that honda link John! is that thing mounted in a truck camper? I can see accordion stairs off the back.

The Profile of the OP who did the conversion says he owns an '04 Alpenlite Saratoga 935.

http://www.rv.net/fo...id/20038531.cfm

You can also see the door in the back wall plus one of the jacks.

One fact that makes his installation is that he could run the exhaust through the rear wall. I think most of our generator compartments are on the side, just behind the driver.

[linda s]

In 1987 that compartment was more likely designed to hold a Kohler 2500 generator. They have not been made in a long time. The Onans 2.8 and 2.5 are pretty durable and a used one would probably be fine if it runs good when you buy it. I see them for sale near me for 800 to 1600 dollars. If there are any rv wrecking yards near you you might find one from a class B camper like a Roadtrek.

Linda S

[Totem]

spot on Linda, but its only $100.00 for a used 2500:

http://albuquerque.inetgiant.com/automobiles/rvs/kohler-2500-watt-generator-13259869

[Derek up North]

I believe Linda was referring to the Onans at that price. Even at $100, a Kohler is no bargain if you're not going to use it because of the noise. Like the Seller.

[straygoose]

In 1987 that compartment was more likely designed to hold a Kohler 2500 generator. They have not been made in a long time. The Onans 2.8 and 2.5 are pretty durable and a used one would probably be fine if it runs good when you buy it. I see them for sale near me for 800 to 1600 dollars. If there are any rv wrecking yards near you you might find one from a class B camper like a Roadtrek.

Linda S

That's pretty much what I'm looking for. I have seen tons of used Kohlers and Onans for sale over the last few years. Someone will have one with relatively low hours for a good price.

Come to think of it, I'm not even sure what size BTU AC I've got. I assumed it was a 13,500, because that's what I've always had. I did not know there was a smaller one. I will have to check soon as I get the RV back. All I know is that it's a Carrier rooftop unit. I figure that will have a lot to do with what I need for power.

Sorry there's still no pics. Apparently the mechanic took the day off or something because my brake job isn't done.

[Maineah]

New Honda 3KW over 2 grand used Onan 2.8 1 grand or less. Honda's are very quiet Onan's are very tough (they make them for the military) If it came out of an RV chances are pretty high they have very few hours on them. They also were pretty popular as camp generators so if you look at a used one I would go for the one from an RV.

[straygoose]

New Honda 3KW over 2 grand used Onan 2.8 1 grand or less. Honda's are very quiet Onan's are very tough (they make them for the military) If it came out of an RV chances are pretty high they have very few hours on them. They also were pretty popular as camp generators so if you look at a used one I would go for the one from an RV.

Oh I'm definitely looking used. I just bought the MH, and while I like her, I'm not willing to invest 3K+ in a genset.. Finding a decent used one with low hours shouldn't be a problem, if the ads on CraigsList are any indication.

Right now, I would just be happy if I could get the vehicle back from the shop and get out on the road. Three days to do brakes? This mechanic is starting to pi$$ me off.

[Totem]

hahahaha thats because he keeps ordering brake parts for 1/2 ton and its probably been upgraded to one ton... My Mech had same issue.

[straygoose]

hahahaha thats because he keeps ordering brake parts for 1/2 ton and its probably been upgraded to one ton... My Mech had same issue.

I hope not, since I made it a point to let him know that. If he ordered the wrong parts, then he's a dumb@$$, and both he and my buddy that recommended him are going to get an earful. I'm usually pretty patient, but I'm in Baltimore and I need to get over the mountains and out of the way of this storm that's coming up from Florida.

[Maineah]

If it has 6 bolt wheels it probably has the bigger rotors and different brake pads.

[Maineah]

I hope not, since I made it a point to let him know that. If he ordered the wrong parts, then he's a dumb@$$, and both he and my buddy that recommended him are going to get an earful. I'm usually pretty patient, but I'm in Baltimore and I need to get over the mountains and out of the way of this storm that's coming up from Florida.

I used to live in Harford county actually in Joppa (not Joppa town) good luck on the storm think it's going north of you.

[stamar]

that project is nice but its too much for me.

i need mine to be externally mounted im sure now so thanks for the info.

[straygoose]

I used to live in Harford county actually in Joppa (not Joppa town) good luck on the storm think it's going north of you.

Thanks, but I got out before the storm. I'm in KY now and on my way home to Texas soon. I work in MD and bought the vehicle there. I have a lot of friends in MD and they seem to be OK, but I also have friends in PA and NJ and they didn't fare so well.

[straygoose]

that project is nice but its too much for me.

i need mine to be externally mounted im sure now so thanks for the info.

It's probably too much of a project for me too, but not for an RV tech, so if I can find an acceptable genset then I will have it all put together at the shop.

No sense in me messing up a perfectly good Toyota by messing around with something I have no business messing with.

[stamar]

Ive forgotten to post this twice now.

But Ive seen a gadget twice now that houses a honda ttype generator in a generator bay like in a toyhome.

Only it slides out of the bay when its open. meaning its outside of the bay when its running. the cover keeps some rain off and it runs in open air.

meant for a small honda or lookalike.

now the reason I never mentioned it even though ive seen it twice is I cant find it online. but its simple as can be its just a tray it slides out.

ive seen it twice in a standard c class motorhome.

http://www.pplmotorhomes.com/parts/rv-locks/morryde-cargo-slide.htm

this is not it but its the same concept.

to me this seems like the best of a few different concepts.

You need to stop and open up the tray, buy you can leave it permanently plugged into the converter box ( upgrade from stock obviously to the best made)

then you dont have to create a furnace space inside the storage thing. and it locks up too as opposed to leaving it on a bumper. out of the weather, and secure unless being used.

you can creat a seperate gas feed to the generator as a safer project leaving it in the storage or just dont use one.

It is project free which is always the goal.

also leave the heavy electric things plugged into the converter box outlets and then small things hooked up to a small inverter.

The generator powers both the battery bank and the ac stuff at the same time.

[Nam]

Here is my weight in on ext. gen v.s. internal gen:

I went thru the trouble of installing a used Onan 2.8 with 82 hrs. on my previous Toy home. Worked great and convenience but it turned the whole house into a message chair...well not all that bad but it's noisy and vibrating while running quite a bit.

On my '90 Itasca, I decided to try the external setup. Just picked up the Honda eu2000i and I do plan to install a slide out tray where I can pull it out and run it while parked only.

The Honda is a lot quiter than the Onan even at full load. The Onan has remote starting SW while the I have to pull start the Honda (the Honda can be remote started for $800 ough!). The Onan can be ran while driving, the Honda cannot. When the coach battery is drained, I cannot start the Onan, same case when fuel tank is 1/4 or less. The Honda can be started at anytime by pulling . The Onan weight twice as much as the Honda but it can run most roof top AC. The Honda can't...well depends but most of the time it won't run roof top AC

Cost wise, the Honda is 1/3 of Onan when new but on the used market, they both cost about the same...go figure. However, the Onan involves installation cost, the Honda is plug-n-play.

Here is the noise level I found on a yahoo auto website:

Noise at full load:
Generator Model 10ft 23ft 50ft
--------------- ----- ----- -----
National Park Noise Limit 74 db 67 db 60 db
Honda EU-3000 (full load) 66 db 59 db 52 db
Onan MicroLite 2800 Gas / 2500 LP (full load) 72 db 65 db 58 db
Onan MicroQuiet 4000 Gas / 3600 LP (full load) 70 db 63 db 56 db
Yamaha 2800i (full load) 65 db
Honda EU-2000 (full load) 59 db
Yamaha 3000 is (full load) 57 db

Noise at reduced load:
Onan MicroLite 2800 Gas / 2500 LP (1/2 load) 70 db 63 db 56 db
Onan MicroQuiet 4000 Gas / 3600 LP (1/2 load) 66 db 59 db 52 db
Generac 40G (1/2 load) 69 db
Honda EU-3000 (no load) 56 db 49 db 42 db
Yamaha 2800i (1/4 load) 57 db
Honda EU-2000 (1/4 load) 53 db
Yamaha 3000 is (1/4 load) 51 db


The noise levels of the Yamaha 3000is
setup using a Radio Shack dB meter:


Position No Load Microwave and A/C on
-------- ------- --------------------
Inside LD (standing by cab) 54 db 60 db
Standing next to Gen 67 db 71 db
10 ft 61 db 67 db
20 ft 57 db 60 db

[Nam]

I was checking out the Boliy generator too...looks interesting but for now I am sticking wiith the Honda

http://www.boliyguy.com/boliy_specifications.html

Not sure if I trust the noise spec.

[Derek up North]

Thanks for taking the time to post those noise levels and take your own.

So you have a Honda 2000 and a Yamaha 3000?

[Nam]

No, I copied the noise specs. from yahoo auto website.

I only have the Onan 2.8 and Honda EU2000i. No Yamaha. Well I have a big Coleman 6500 contractor generator...very heavy and noisy...only good for construction job site.

[Derek up North]

Ah. You'd best go and correct the noise readings you took. You say it's a Yamaha 3000.

[zero]

Seems posted noise specs can be a little misleading when not given in 10 X Bell Labs (dB) along with the distance from the generator where the noise is actually measured. I've got many spec sheets on various generators. Some give NO distance specs, whereas some show the dB reading taken at 15 feet and some at 30 feet.

I've got a pair of Honeywell 2000i inverter gennys that operate at 1/4 load making 53 dBs at 15 feet. Home Depot was selling them in parking-lot sales for $399 each which was a fantastic deal. Wish now I'd bought more at that price. Also . . . unlike an AC generator, an inverter generator can make AC power at any RPM. The lowest noise rating posted is at 1/4 load they but they can also run slower at 1/10 load if that's all that is needed. An AC generator must run at one fixed speed to make the proper Hertz Cycles when there is AC demand.

Regardless of what the generator is - you get 20 RVs parked 30 feet from each other with generators running all day - colllectively they make noise and can ruin an otherwise quiet rural campground. I'm not "anti-generator." Good for some places and do not belong in others. We went to a very remote campground last summer in the eastern UP of Michigan. Although the place was near empty we got an RV that pulled in next to us. Ran the generator all day long to keep their AC going even though we were lakeside and it was mabye 80 degrees F outside? We finally had to leave - could not stand the constant day and night humm from our "next-door" neighbors.

[Nam]

I am with you, jdemaris on the use of Gen set on camp grounds. I don't know what's the reasons behind staying inside an RV with the AC on when going camping all day long...I may well just stay home. For this reason, I actually removed the roof top AC on mine for now. I occasionally use it as an office in summer but that's when I plug in and AC could come handy.

[Maineah]

It's all about respect there are those that really don't care if their generator is noisy guess that is why the Federal parks have noise standards at least it keeps it down to some thing tolerable. The party all night group is equally as bad.

[stamar]

http://rvnow.rvtravel.com/2010/04/build-your-own-rv-slide-out-storage.html

heres a do it yourselff for the slide out generator. A honda style camp generator does cover everything Ive heard of except the overhead AC unit.

so in the event that didnt exist it would be the best solution by far. somewhere earlier in this thread there is even a write up for creating its own gas gravity feed.

so except for running while driving... and for running the overhead ac unit.

[zero]

I would never install a gravity feed gasoline source to an RV generator. It's asking for trouble and a possible fire. With a float-operated carb - all it takes is a sticking inlet needle, a spec of dirt, or leaking gas line and you've got gas leaking all over the place. Gravity feed is fine IF you have a way to make sure the gasoline cannot flow when the generator is not running. Manual valve or install a 12 volt operated fuel shut-off valve. Without it it's a fire waiting to happen. Some engines with gravity feed have gas valves that get turned on by engine oil pressure. Modern cars and trucks get the fuel pumps turned on by sensing when the alternator is charging. Every big engine powered generator I've seen with a gravity feed tank has an electric gasoline shut-off valve. I'm not suggesting buying from any of the links I posted. They are just examples. I tend to buy cheaper.

http://www.dan-marc.com/79-afc11112.html

Vacuum operated fuel pump are cheap and easy to install on any gas powered generator so getting fuel without gravity feed is an easy fix with no extra wiring.

No good on diesels though. Vacuum pump works of the vacuum pulses whenever a gas powered engine is turning - including when cranking the engine with the starter. Many generators and all chainsaws have them. Most diesels do not have engine vacuum so no good on them.

http://www.jackssmallengines.com/Parts-Lookup/520590/57270/ps?gclid=CPic9sPNg7UCFY9DMgod2UsAiw

http://www.jackssmallengines.com/Products/WALBRO/Fuel-Pumps-Diaphragms/520159/57250

http://www.ebay.com/itm/SMALL-ENGINE-VACUUM-FUEL-PUMP-FOR-BRIGGS-KOHLER-HONDA-OTHERS-PART-491922-/330833184704?pt=LH_DefaultDomain_0&hash=item4d0731c7c0