how to exhaust generator out of roof without rain water getting in engine?

[Kevin Warnock]

I am at the stage of thinking about how to exhaust my Honda EU1000i generator that I've adapted to propane and am running in a quiet box. I am trying to keep my RTS looking stock, so I want to avoid any projections from the roof that would be visible from the ground as seen from 50 feet away. I want to exhaust out the roof so as to lessen the chance of bothering people with a curb level exhaust. But if I just run a pipe to the roof and have it exit, won't water fall in when it's raining? My RTS itself has a roof exhaust for the engine, so how does my Series 50 deal with water falling down the pipe? In the engine case, the exhaust pipe curves back so the opening is actually pointing back, not up, but in big storm, I think some water must fall down the pipe. Does it simply get boiled and expelled as steam?

For my little Honda, I would prefer an exhaust pipe flush with the roof, at the center of the bus left to right, if the generator can tolerate some water getting down the pipe. If that's not OK, how about installing a small box, say 3" x 3" x 3", with no top on it, flush with the bus roof and extending down 3" into the bus. Then I could have the generator exhaust pipe enter the bottom of this box and have the outside part of the pipe curve back 90 degrees just like the bus engine exhaust does. This would keep out a lot of the rain. Of course, I would have to drain the bottom of the box through to the ground, via a pipe I would run inside the bus.

If these ideas won't work, any other suggestions?

Thanks

[robertglines1]

rain cap. small tractors have exhaust thru hood and use a flapper valve ie rain cap..

[Busted Knuckle]

1967_MCI5a if it were me I'd run the generator exhaust over next to the engine exhaust and come up as high as it with a 90* also! Or yo could put one of the old style exhaust flappers on it like the old tractors & Semi trucks used to use! Either way I would not leave it flush with the roof! JMHO FWIW
 BK  

[Tenor]

How about this?

http://www.busconversions.com/bbs/index.php?topic=12727.0

I just updated it.

Glenn

[BG6]

. Does it simply get boiled and expelled as steam?

Nope.  I gets blown out when the engine starts.

This can be very amusing to watch.  It looks like a whale spouting, and if timed properly, can drench a particularly-deserving passerby..

. . .not that I would ever DO such a thing, you understand . . .

[James77MCI8]

Can you generator tolerate that much back pressure on the exhaust? If so the flapper on the end of the pipe will work.

[Kevin Warnock]

I don't know. How can I do a simple test before I install it? If I just put a 10 foot exhaust pipe on the engine and run the generator and it runs without apparent distress, does that mean it's OK? What kind of problem am I looking out for?

Thanks.

[PCC]

You could put a tee at the top of the exhaust as it exits the roof, and the rain might choose to go another way than down your pipes. They did that on cabooses on trains, as I recall (am I dating myself?)

Don't forget that hot air rises, so the exhaust will rise up the vertical pipes easier than flow along a horizontal line.