Honda Generator EU 3000is-Installation do's and dont's?

[LJ-TJ]

Well lads, You did to good of a job helping me out with my Trans Cooler problem I thought I'd try a gain and throw this out atcha. I sold my Onan 4000 generator because It just got to difficult to get parts for it. So I ended up buying a Honda EU 3000is with the intention of installing it in my old generator bay. They say you shouldn't enclose it because of heat. The generator bay is pretty big. Any thoughts on the best way to go about this. Have any of you tried this.

[BigAlsVehicleEmporium]

I just started going down a similar path. I tried to get my Onan 4.0 CCK generator working. Judging by the state of the plugs, it burned oil pretty good and the inboard cylinder hadn't been firing in a long time. Compression on that cylinder was 0 psi and I decided to pull it and not mess with it. If anyone needs/wants one let me know!

I'm going with the Predator 3500 myself because the Hondas are a little outside of my budget. I think mounting it in the old enclosure will be just fine with proper ventilation. The Onan had a snorkel that allowed the flywheel fan to pull in outside air from under the coach. The exhaust then routed out the bottom. The hot air left the cabinet through the louvers on the door.

To duplicate this, I could route the exhaust out like the Onan had and put an intake fan in the old intake slot. Another option would be to run the fan as an exhaust fan and not worry about opening up the case and figuring out a way to plumb in the muffler.

I'm going to hopefully pick one up on sale this 4th of July and then I'll see just how difficult it would be to tap into the exhaust. Either way though, I think it definitely needs forced air ventilation.

Has anyone here installed one already?

[DaveVA78Chieftain]

On the original generators the air was sucked in thru the access doors and exhausted out the bottom the rig.  If you think about it this makes sense because you do not the very hot air of the engine being blown across:
1. Carburetor (prevent fuel percolating)
2. Control relays and boards (early heat related failure)
3. Generator (overheating of windings)
4. Wiring, etc.
5. fuel tank (Excessive tank heat as well as pouring gas in the tank over a very hot engine)
Also, look at the operators and installation manuals for the original generators and this will be confirmed.

Heat removal (both cooling air and exhaust pipe heat) is essential in this enclosed  space.  Generators like a Honda EU3000 were designed to be operated in open spaces (free flowing air flow around and thru the generator) so establishing external air flow thru the compartment is essential.  I have no clue what say a 4.0 CCK air flow value is but I suspect it was fairly high so over design. If I remember correctly, the EU3000 fluctuates in speed based on engine load (electrical load demand) so heat load will also fluctuate.

Exhaust design it critical also in that you do not want back pressure on these engines which were not designed for this application. If determine to put in this space, look at go cart engines for potential exhaust pipes fabrication.

The EU3000 uses a gravity feed carburetor with the gas tank and fill valve at the top center of the unit. Will you be able to fill the tank with fuel?  I suppose you could design in a electric fuel pump however it will need to be very small psi due to prevent forcing the carb float needle of the seat which is only designed for gravity feed tanks.

Maintenance - Gonna be very difficult to access things to change oil, plugs, filters, etc. for a engine not designed with this space in mind.
EU3000 Maintenance

Vibration - will need to design your own anti vibration mounting system or your going to feel all the vibrations.  Yes the original engines had vibration mounts.

All this is why I eventually had my external generator mounted to trailer hitch mounted luggage rack.

Lastly I am not saying don't do it, I am providing info for what I went through when I attempted this.

[LJ-TJ]

Hey Big Al thanks for responding.Looks like we're going down parrell tracks. Dave your opinions are always welcome. I love the way you process challanges. You've have helped me and got my bum out of many a situations over the years. I could never thank you enough.

https://www.youtube.com/watch?v=pWzF2TkXM-I

[BigAlsVehicleEmporium]

Dave,

All great thoughts and info, thanks! I'm surprised to find out that the air scoop coming out of the bottom was an exhaust scoop. I never had mine running so I just assumed since it was right there at the flywheel that would be an inlet. Looking at it more though, an exhaust scoop makes sense from the shape of the cowling.

I'm curious what cfm fan would compare to the original engine fan. Did you ever feel the exhaust air duct of yours while it was running? If so, was it more/less/similar to a leaf blower at idle?

The front cowl/ducting of my generator has a 12" diameter. Amazon has a 12" automotive cooling fan for $23. It is spec'd at 600-800 cfm. The generator cabinet in my '72 D20 is roughly 3' x 2' x 2', or 12 cubic feet. On the lower end, this fan would move that same volume of air every 2 seconds. Obviously the flow isn't going to be such that it's a total evacuation of air in that cabinet every 2 seconds and ducting would cut into that cfm number. If it replaced the air around the generator every 8 seconds or so, that seems like it would be pretty similar to open air to me. Does that seem reasonable? Plus, it's noise level is rated at 50 dB so hopefully it wouldn't add significantly to the 56 dB noise level of the Predator 3500.

A low pressure electric fuel pump, possibly in combination with a regulator, would work for fuel supply. My concern would be safety. I think I would supply it 12V using a relay with a 120VAC rated coil, supplied from the output of the generator. That way if the engine died it would kill the fuel pump. I'd probably wire a 12V relay in parallel with it and have a Prime button on the dash that would let me fill the bowl if it had been sitting. There are tutorials online on how to use an inexpensive, off the shelf door lock actuator to electrify the choke, so I'd probably wire that into the prime circuit as well. This should give me full ability to start it from the driver's seat.

I've still got the large rubber mounts for the Onan generator and they're in great shape. If I built a mount plate that went between those and the existing shelf/floor plate and mounted the generator on that, it seems like vibration would be less than with the Onan as the generator is shock mounted already in it's closed frame.

The original generator on my rig weighed 340 lbs. The Predator 3500 comes in at a svelte 98 lbs. At that weight, I'm comfortable putting a handle on the front of the generator shelf and sliding it most of the way out onto some jackstands for any maintenance. For a Chieftan level of fanciness, one could utilize a $40 set of 24" drawer slides comfortably rated at 250 lbs to make that shelf slide out for maintenance access.

Like I said, all good thoughts and questions. Please keep them coming! Hopefully the Predators go on sale for the 4th. If they do, I'll start looking at this a lot more seriously!

[Eyez Open]

I've been there, while I've decided to go another path I too was going with a predator. Actually my neighbor has a few of them..they are amazing. The RV i have had a Onan 6500 self cooling genset, the cooling fan was a industrial design,actually the entire system was a industrial setup.

Had I gone with a genset system I would have gone with a predator system and a morryde pull out.

https://www.etrailer.com/RV-Cargo-Slides/MORryde/MR79RR.html

[LJ-TJ]

  WOW, good stuff guys. Here's the route I've gone so far. The honda ways 130 lbs. With the sliding tray it allows me access for fuel and maintance.

[DaveVA78Chieftain]

The generator for the 78 Chieftain I had was long gone when I bought it so have no point of reference how much air flow the original Onan gen had. For the Honda, being a smaller inverter based gen I would think there would be a lot less air flow required however inverter based says electronics which means heat sensitive.
On a 78 Chieftain the gen tray had to be unbolted then dropped down to the ground so I did not have a sliding tray option which is another reason for the trailer hitch mount.
Vibration mounts are typically weight rated (moment rated) so have no clue how that 250lb difference will effect their damping characteristics (to stiff for the lighter weight?)

[DaveVA78Chieftain]

BigAl,
Your fuel pump and choke ideas are sound but please understand that many here, while energetic and willing to learn, they need a lot of details on how to do something that may be simple to you or I. So links and extensive details go a long ways here.

Example: Upgrading from a PD694 (no 12VDC charging capability with manual transfer switch) converter typically installed in pre 74 rigs to a modern 3 stage converter/Power Panel is a daunting task for the person afraid of electrical things in general. Even the auto battery relay transfer power center that replaced the PD694 to 3 stage converter/Power Panel is a daunting task for many people.

Thanks - Dave

PS: TJ's post on what he has done is not lost on me in this regard - Good job

[BigAlsVehicleEmporium]

Dave, great point about the lighter weight affecting the vibration damping. I hadn't thought of that. I don't have a reference for vibration either, so I'll just see if it seems like too much I suppose.

And you're right about the electrical details as well. I have a MS in Electrical Engineering and forget all too often that not everyone has the same background that I do. When I do the conversion in my rig I'll make sure to draw up the schematic and post it in my project blog so anyone can follow it.

Well, I was really hoping that the Predator 3500 would go on sale for the July 4th weekend but it didn't, dang it. And the Harbor Freight 20% coupons aren't worth much anymore because nearly everything is excluded. I don't want to drop $900 on a generator so I'll probably try to pick up one of the refurb ones locally for $500. I'll let y'all know how that works out!

Alan

[LJ-TJ]

I'm sure you lads have checked these sites out all ready

https://www.youtube.com/results?search_query=predator+exhaust+extension

https://www.google.com/search?client=opera&q=Preditor+Aux+Gas+Tank&sourceid=opera&ie=UTF-8&oe=UTF-8

[LJ-TJ]

Small up date. Anyone looking for a slid out tray inexpencively. Go to the Auto Wreckers and look for an old amblance or Fire Truck. Got the generator on the tray and wired. Works like a dream.Now I have to figure out hot to deal with the exhaust and fresh air intake.You can't even hear the darn thing running when your in the motorhome.There's some great stuff on exhaust for the preadator from Harbor Freight on Youtube.