Air Intake on Roof ref. Songman

[edroelle]

Rather than add to the post "engine/ gen exhaust out of the roof??", I am starting a new post.

Songman wrote, "I'm not going to run the exhaust through of the Eagle but I am planning on putting an air intake up there to get a good supply of fresh air. And since my generator will be in a compartment beside the engine, I plan to run the gen exhaust through the regular engine exhaust out the back of the bus. Should make it quieter and also keep it away from other bus nuts when parked."


Be very careful with your design of an air intake on the roof.

Last week, while at a campground in Florida, they towed a 1999 Bluebird Wanderlodge to the Detroit Diesel Dealer.    The Wanderlodge has its air intake near the roof.   The owner of the campground had not used the coach for a long time.   When it would not start, the Detroit Diesel Dealership came out and identified that rain and/or wash water, came in the air intake.  They are afraid that besides getting into and damaging the turbo, that it also got into the Series 60 cylinders.

What surprises me, is that this was a supposedly PROFESSIONAL installation !!

BTW, the tow truck driver did an excellent job at preparing the coach, and getting the Wanderlodge out of a tight spot.   (Hopefully no one will need this but ... Revis Towing out of Ocala 352-622-6977)

Ed Roelle
Flint, MI

[luvrbus]

Some of the model 10 Eagles had a roof mount air intake from the factory and never had a problem with water or leaves fwiw    good luck

[Songman]

Thanks Ed. I have already though about the dangers of water getting into the intake. I figure you have to have a P-trap like in a sink but with a drain hole in the bottom of it to let any water that did come in the inlet escape. I would appreciate any further discussion on this idea though. I just want to get good cool clean intake air. I think that Eagles in particular aren't designed to get the best intake air so I want to make it better if possible.

[Songman]

Clifford, is that actual rook mount or is that the one that is behind the rear window on the curb side? I don't think I have seen the actual roof mount. I got the idea from Duane's Model 20. He mounted a big snorkel up on his rear corner. I figured I would try to mold something into the rear cap.

[Busted Knuckle]

Dina had a roof top air intake too! Just be careful and make sure to do what Dina didn't and screen it or something to keep birds from building nests in! I know of at least a dozen Dina's that have had this problem!
Belfert's included! FWIW   BK 

[John316]

Ours (DL3) air intake is on the driver side, top. It is mounted right next to the roof on the side. We haven't had any problems.


God bless,

John

[Songman]

You guys give me opinions on this...

I've got that big square R&M rear cap. I was thinking about building some sort or air deflector onto the top rear edge. Remember those little valances they had on Chevy Blazers back in the 90s that pushed the air down across the back to keep the rear window from getting so dirty?

I was thinking of molding something similar into the top of the rear cap, but closing in about a 12-18" section on the curb side to use as the air intake. Putting a screen on it is a good suggestion, BK. Of course, I would want to shape the thing and make it look like it is actually a part of the bus instead of something just thrown on top.

Ideas welcome...

[belfert]

As BK indicated, the roof air intake on my Dina was indeed plugged due to a bird nest built inside.  It wasn't as bad as some as my aluminum intake pipes were not crushed due to lack of airflow.  BK knows a charter operator who had to rebuild or replace the Series 60 in a Dina due to air starvation.

I ended up putting hardware cloth over the intake after dismantling and cleaning the air intake.  The hardware cloth is secured by stainless screws and fender washers driven into the fiberglass cap.  (It looks bad, but better than no air flow.)  Dina placed an Donaldson air/water seperator in the vertical portion of the intake pipe to get avoid water ingestion.

[Rick Brown]

Here is an air intake on the roof of a 4905.
http://intermountainac.net/Bus/Eng1.JPG is a rear view
Keep in mind that the decorative motif is battle bus.  This a dual wall arrangement that replaced the rear window.  Notice the pvc tubes sticking out on either side just below muffler bottom level, those are the drains for the air intake space.
http://intermountainac.net/Bus/Eng8.JPG is a side view. Not clearly visible are the 1/4" mesh ss screens that keep the birds out.
http://intermountainac.net/Bus/Eng3.JPG is a K&N air filter accessible from inside the coach, shown with door removed.
This has worked well for me and I travel dirt roads to dirty places like the Burning Man festival.  Air cleaner needs cleaning about every 50 hours depending on where I've been.  Good for starting on cold mornings with a 1 to 3 second shot of ether on the filter element.  Also gets read of the oil bath air cleaner in the engine compartment.
-RickBrown in Reno, NV

[Van]

Don't know if you can see the snorkel on the rear of this drawing,but this is what I had in mind



Or how about this for a deflector (rear)Oh this is my low rider rendition ;Dby the way.

[belfert]

I would think a forward facing air intake would collect more bugs and debris than something to the side or rear.  Just something to think about.

[gus]

My opinion is that you need to find a high pressure point and the roof may or may not be one. Using the same location as the original is probably the best bet if this is possible. If you find a good high pressure point a scoop is not necessary.

Air flow is pretty tricky and sometimes what appears to be a perfect spot turns out to be a low pressure area. I found this out a few times when trying to mount aircraft instrument venturis. I got fooled a bunch of times.

If the intake duct has a circular path with a water drain at the bottom you probably won't have any problems.

[TomC]

My intake is a stack on the right side with a right facing leuvered vent.  When I turbocharged the engine, I had to change the air cleaner and enlarge the stack by adding another vent opening.  Now it works well with water vents both in the ducting and in the air cleaner.  Good Luck, TomC

[NJT 5573]

Considering the turbos job is to suck air into the  engine and pressurize the cylinders, if you have adequate airflow it shouldn't matter where the air comes from as long as its cool and dry.

The best running  2 strokes I ever had always had 2 aircleaners on them and that is on the list for my Eagle someday.

The raked bus looks cool but every bus I have driven that was low in front changed lanes everytime the cross winds blew. Raising the steer axle cures all the handling problems in high winds.

[Songman]

Van, you crack me up with those chopped hot rod buses! haha

The first picture is actually similar to what I am thinking of. But I will try to incorporate something that looks like it is a part of the rear cap and goes all the way across. I am thinking from the rear it would look sort of like the rear of Merle's new bus but the opening would be farther across the rear and would be angled down to direct air downward to keep the rear cleaner.