The Generator-Line Enclosure Exhaust System

Wayne, I think you would have exhaust gas and muffler temperature somewhere in the 500-700F range.

Luckily your generator location and the ladder make installing a secondary exhaust pipe easy. I'd suggest to come off the Honda with metal pipe and fittings. Your exhaust pipe extension doesn't even need to be attached to the Honda, clamp it to the RV body or the ladder. If you use a metal pipe and make it long enough, you'll also end up with a good FM antenna, lol.

Reddog1 wrote:
Thanks for your input.

You're welcome! It's a fun thought exercise. ;)

I just checked, and the air flow in the Honda 2000 is in throught the front and side vents, with the exit out through the plastic muffler guard. So, it could be enough flow with the EUX2 shroud and 4" flex to both cool and push the exhaust out.

ShapeShifter, I think you are correct neither system is really needed for me, more curiosity than need. You made several good points, I seldom if ever attend a rally, race, dog/horse show, or similar event where rigs are packed in like sardines.

Thanks for your input.

Wayne

Reddog1 wrote:
Considering I have never had a problem with what I have, I am probably just fixing something that is not broke. With my solar, I seldom run the Honda over twenty minutes a day. Maybe run for a few hours a couple of times a year.

Sounds to me that the whole concept isn't really needed for you. If you run it for such short durations, and so seldom, it hardly seems worth the effort.

The biggest concern would be if you frequently attend a rally, race, dog/horse show, or similar event where rigs are packed in like sardines. In that case, with your setup, the exhaust might be blowing directly into the window of a neighboring rig. But since you use it so infrequently, simply taking the generator off of the platform and aiming it more carefully could be a whole lot less work than adding a stack.

But hey, if you feel like tinkering and experimenting, go for it! (But if you've got that much free time, head over this way and help me with some work on my rig! :B)

Considering the shroud covers the entire muffler, and the exhaust pipe flows directly into the 4" flex, it appears to me that maybe the size of the flex and air flow of the muffler heat will pull the exhaust up and out. Guess I will have to try it to find out. The only cost should be the Aluminum duct flex shaped to cover the Honda plastic muffler guard and a little Duct tape to fasten the flex to the plastic muffler guard.

The mounted height of my Honda is high enough I think the flex will be out of harms way.

Considering I have never had a problem with what I have, I am probably just fixing something that is not broke. With my solar, I seldom run the Honda over twenty minutes a day. Maybe run for a few hours a couple of times a year. The GenTuri/EUX2 shroud has me curious, so I will probably give it a try.

Wayne

You're a better judge of how much heat there is and what you can handle. It's been a while since I've run my little Honda for anything serious since getting the current rig, so my recollections have faded and can be flawed. All I know is that the current on-board 8kw Onan diesel can really pump out the heat! :E The Honda certainly does put out less.

I was thinking this new shroud is the way to go, but if it ends up as cool as you think it will be, then Mike's version may have some merit. The definitive answer would be to ask Mike how hot that elbow and nipple gets under heavy load.

Still, the more I think about it, that flex hose will be a lot easier to route back to the vertical stack. (And more easily damaged by inadvertent contact!)

The Honda OEM plastic muffler shroud is within 1/2-inch of where the exhaust comes out of the muffler. Using the Street Ell as in Mike's version of the GenTuri, the OEM exhaust pipe is easily within 1/4" (or less) Street Ell. The Street Ell would act as a heat sink, and due to the Street Ell being screwed into the OEM muffler shroud without melting the plastic suggest the Ell must not get too hot.

I can put my hand anyplace on the OEM plastic muffler shroud, including where the muffler exhaust is, with no problem. Definitely hot to touch the metal muffler or exhaust tip output.

Wayne

If that shroud also captures the air from the cooling fan, then it is likely that the resulting mixture of air won't be hot enough to melt a plastic pipe.

If you go with any variation of the GenTuri or Mike's version, then that metal piping could still get quite hot since only the exhaust gases will be in the initial piping section, and no cooling air will be mixed in until you get to the venturi opening at the plastic pipe.

Holding your hand a few inches from the exhaust allows a lot of ambient air to mix with the hot exhaust to cool it down. Even under the vinyl cover, the exhaust and cooling air probably blew the cover far enough away from the exhaust to allow some mixing and cooling.

If you run the generator under load for a while, and then touch the actual metal of the exhaust pipe (that little bit of metal tube showing through the plastic casing) I'll bet you'll find it quite hot. Any metal exhaust piping connected directly to that output with no additional cooling air is likely to get just as hot. The little Honda's don't put out huge amounts of heat, but the exhaust heat is still concentrated on that little output. If the muffler wasn't shrouded by the plastic casing, I'm sure you wouldn't want to touch it directly.

Given that the exhaust is at such an exposed location, and easy to accidentally contact, maybe your best bet is to use this shroud you found. That's assuming that it does indeed mix in the cooling air from the engine fan. It would be easy to route that flex hose section back to the camper body, and then run up from there with rigid plastic.

The Honda 2000 engine is so small, it does not produce much heat. With your hand, very little heat 6-inches away from the exhaust.

I did not have my cover secured properly when pulled back for operating the Honda in the rain, and the cover slid over the exhaust. You can see where it burned a hole in the vinyl cover. Actually, it did not burn, just melted the plastic of the vinyl, with no harm to the cloth backing.




The EUX2 shroud covers the entire muffler/exhaust assembly, and uses a 4-inch aluminum flex (clothes dryer) to divert the exhaust. It relies on the air flow from the honda exhaust system to move the exhaust out of the flex. I am not sure if the Hondas fan blows out the exhaust end of the Honda. I will have to do some testing to see just how hot it gets a few inches from the muffler, and also to see if the Honda fan pushes air across the muffler.




I have several options for routing the flex, to move the exhaust above the roof of the TC. I could use only enough flex to connect to a solid piece of plastic pipe, probably plastic a post or plastic downspout.

Wayne, while expensive, that hood looks like it would be useful for situations where the generator is enclosed in a box or compartment. But that's not your situation.

The GenTuri is a proven design, and you'd never be able to take mine away from me, but it's probably a lot bigger than you need. Yes, it does come with several adapters, but none small enough that would work with the tiny exhaust output of the Honda.

The way you have your generator mounted, I think you'd be much better off with a variation of Mike's home made stack. He kept his plumbing short until he got to the stack, but if you go with the next size up you could probably be safe to go a little longer with the metal pipes, You could then run them closer to the vicinity of your ladder, then run the plastic pipe up along the wall, clamping it to the ladder for support.

Just be aware that while the plastic will get warm (warm enough that it's uncomfortable to hold, but not hot enough to burn) the metal will get very hot: hot enough to cause some bad burns! With your generator mounted at that height, and the exhaust by the outside corner of your rig, it might be a concern.