best way to vent?

[uemjg]

I plan to install my generator in the middle bay of my MCI-8 bus and wondered what is generally the best (better) way to bring fresh air in and exhuast hot air out?

It's liquid cooled and diesel with a electric pusher fan i on radiator.

thx.

This may be a dumb question, but since its a diesel engine does it also use diesel motor oil?

[Len Silva]

The best way to vent is in the off topic section.

[uemjg]

Well I guess that was #3691.

[Lin]

Ours is mounted across the bay.  It sucks air in from a grating on one side and blows it through the radiator out the other side.  I placed the exhaust pipe under the radiator so the fan is also blowing the exhaust away from the bus.  If there are other people nearby, I have a tube to run the exhaust to the roof.

[bevans6]

More answers than busnuts!  You want fresh air in/out to flow from high pressure to low pressure, so the best would be intake from the side of the bus and output to the bottom under the floor.  You can arrange an air dam just in front of the lower output opening to increase it's negative pressure.  Exhaust ultimately needs to go high, some take it up directly to the roof, others send it under the floor to the rear or to the side.  Low mounted exhausts need to consider exhaust ingress to the interior of the bus, and a high mounted extension is very good for while parked.

Brian

[TomC]

My genset uses a remote mounted radiator (because of space limitations).  The gen compartment is entirely enclosed with the air cleaner outside the cabinet also.  To ventilate the cabinet I use an 8" inline bathroom fan from Graingers split into two 6".  The fresh air blows on the gen side and the hot air comes out of the front of the engine side in two 6" vents-so the air is circulating down the entire length of the gen.  Also have the exhaust manifold and exhaust pipe wrapped for heat.  Good Luck, TomC

[uemjg]

good suggestions guys...what oil for my generator's diesel motor?  Diesel oil for it?

[TomC]

Typically they suggest normal 10W30 oil.  After I had a few hundred hours on the genset, I switched to 15W40 that Diesel truck engines use.  All gensets and APU's that are used on big rig trucks are made to run on 15W40 for ease of using a single oil for both the putt putt engine and the big engine.  Course, if you have a 2 stroke Detroit you still have to use straight 40 weight.  This would be to thick for the small genset.  Good Luck, TomC
P.S: I belong to a men's chorus (Masters of Harmony.org) that has a Chevy pickup to haul our 5th wheel trailer with equipment around.  The entire rig weighs 16,000lb and with the 454 in it, we get all of 6mpg with it.  I changed to the 15W40 oil, and the engine loves that oil.  Have 60psi and doesn't burn any.  Quality oils are always the best to use.

[Uglydog56]

Although mine is mounted longitudinally, my genny also sucks from the side and blows out the bottom.  I, however, run straight 30w in mine.  No rational reason for it.  I run 15w40 in everything I own except the lawnmower and the generators.

[Oonrahnjay]

Typically they suggest normal 10W30 oil.   (snip)   

      The Cummins/Onan customer service people eagerly recommended Mobil 1 Synthetic 5W-40 "Turbo Diesel Truck" oil.  It is becoming hard to find in quarts (only gallons) but my VW TDI loves it.   As a "full synthetic" oil, it may not be good for people with substantial hours on their generators.

[Kwajdiver]

I install air ducts, bought at a marine supply store. They look great, chrome, and work really well.  Just mounted them on the bay door.

Bill

[buswarrior]

Think hard about under slung exhaust systems and a grassy field.

happy coaching!
buswarrior

[Kwajdiver]

Here's a photo of how I vented my gen set.

By the way, this coach is for sale.

Bill

[Carbone]

I sell oil for a living. Mobil, Citgo, Mystik, and a few others. My Isuzu diesel water cooled unit calls for 10w30 full synthetic. "Diesel" engine oils are much different than automotive oils and even I found it odd that an automotive grade oil was original equipment in my unit. Look up the manufacturers recommendation. It is recommended for more reasons than you could ever imagine. Oils designed for diesel engines would be tough on upper end components in this application. There are many misconceptions when it comes to oils but there is no doubt that multi-billion dollar companies do extensive research and make their recommendations based on facts and longevity.

[HB of CJ]

Excellent answers already given.  Do you plan on running the gen set while driving down the road?  High pressure to low pressure.  Cold low position and hot high position.  If possible gentle sweeps instead of tight bends.  Sometimes a helper fan on the inlet side or perhaps somewhere in the works works.

Running the gen set down the road presents challenges.  FWIW, Crown Supercoaches used a big driver sided side mounted radiator in front of the midships pancake engine.  Cooling air was pulled thru the radiator via a BIG fan mounted just left and forward of the engine.

Used a big sweep type intake duct like on an airplane turboprop.  Below the fan was a big mud flap thingie that ran tranversely side to side of the bus just in front of the engine down to about 6" off the road.  Flexible rubber.  Always got beat up by road strikes.

The setup exploited a high pressure--low pressure situation that existed driving down the road.  At speed the fan was greatly assisted by this effect.  Sometimes engineering solutions must take into consideration all the possible conditions.  What may work sitting may not work driving?  Sometimes.   HB of CJ (old coot)