Serenity - 2002 Thomas HDX

[RHOMBUS]

Those are inlets (intakes). I call it ducted air because it really isn't doing anything other than providing a couple more channels for air to get to the intercooler. There shouldn't be a ram-air effect unless I put a scoop over the holes. The picture showing the holes with the shiny rings around them are the outlets in front of the intercooler. The intercooler goes up much higher, but due to the body design, that's as high as I could make them.

The original design of the radiator and intercooler layout put the radiator facing flat to the driver's side, and the intercooler at a 45 degree angle to the radiator. You can't even see the face of it in any of the pictures. Therefore, whatever air get pulled through it is almost an afterthought, so I'm hoping this will help it along some.

[cadillackid]

im trying to figure out how that intercooler setup works at all unless your bus is hot and the fan is running... seems like you would get almost no air through when you need it most... ie climbing a hill or starting out with the blower spooled high...

unless the fan is engaged all the time?

-Christopher

[RHOMBUS]

That's what I was thinking too. If the main fan isn't turning, then I don't see how the intercooler would even work at all, unless the air intake temp is being monitored and the system can trip the fan for that condition as well.

[aaronsb]

On a cummins 8.3, there is a charge air override control valve widgulator that kicks the hydraulic fan motor into full power. With the charge air reaches a temp, it opens an electric solenoid valve and allows full hydro volume to motor.

Check out this pdf, page 5

http://www.centralstatesbus.com/2003...s/a3hydfan.pdf

Originally Posted by RHOMBUS

Those are inlets (intakes). I call it ducted air because it really isn't doing anything other than providing a couple more channels for air to get to the intercooler. There shouldn't be a ram-air effect unless I put a scoop over the holes. The picture showing the holes with the shiny rings around them are the outlets in front of the intercooler. The intercooler goes up much higher, but due to the body design, that's as high as I could make them.

The original design of the radiator and intercooler layout put the radiator facing flat to the driver's side, and the intercooler at a 45 degree angle to the radiator. You can't even see the face of it in any of the pictures. Therefore, whatever air get pulled through it is almost an afterthought, so I'm hoping this will help it along some.

[RHOMBUS]

Aaronsb: hopefully the same type of system is used for the air-clutch fan I have.

[dan-fox]

Is this engine oil operating the fan motor? Or do you have a completely separate hydraulic pump/motor/reservoir system? If so, does it run anything else? TIA

[RHOMBUS]

The way mine is set up (2002 Thomas rear-engine) is a belt-driven fan with an air-actuated clutch. I don't know how the hydraulic fans work.

[Docsgsxr]

on my 3126b250 the fan runs when the motor is running. nice job on the vents. it should increase airflow quite a bit.

[Tango]

RE's are notorious for having poor airflow over the rad & intercooler. Typically, any given engine in an RE will have a much bigger rad than the same motor in an FE. Anything you can do to increase airflow is a bonus.

[Scooternj]

Originally Posted by Tango

RE's are notorious for having poor airflow over the rad & intercooler. Typically, any given engine in an RE will have a much bigger rad than the same motor in an FE. Anything you can do to increase airflow is a bonus.

That's why I went for an IC bus. 2 YUUUUUGE vents in the back, plus flip up work steps, the tunnel, and a full size rad and fan. But then when it comes to buses, just like the Big 3, everyone has their preferred builder

As for the new air ducts, see how well they work and maybe consider turning them into ram air intakes if there isn't any improved cooling.

[RHOMBUS]

Note to self: take better and more pictures from many angles of existing wiring before taking it all apart and relying on memory.

Fortuately, I have wiring diagrams, but even those take a while to go through. The little letters and numbers on the wires can get hard to read.

[Scooternj]

That's why I plan on rewiring the electrics. Especially since it doesn't support 2 wire LEDs

[RHOMBUS]

Speaking of LEDs, scooter, I plan on every last light on the bus, inside and out, being LED. Would it be bad to ground them to the chassis like normal lights?

[dan-fox]

Boy, I wouldn't. Just an opinion from an old guy that used to build electronic chassis before he got seduced by the Dark Side and went to software. I never trust a chassis ground; I always run a black wire back to a known good ground somewhere (like a terminal strip with a big black wire going back to the battery).

That's just me, but it'll nip an especially annoying class of problems in the bud.

[cadillackid]

Originally Posted by dan-fox

Boy, I wouldn't. Just an opinion from an old guy that used to build electronic chassis before he got seduced by the Dark Side and went to software. I never trust a chassis ground; I always run a black wire back to a known good ground somewhere (like a terminal strip with a big black wire going back to the battery).

That's just me, but it'll nip an especially annoying class of problems in the bud.

I aleways grounbd certain things directly with a wire and other things I allowed to be chassis or body grounded..

on cars i always had a couple body grounds separate of the chassis ground... granted this does run the risk of a ground loop but theoretically if you place a bodyt ground on each side of the body.. (nice and heavy) directly from the grounbd bar and then re-set the main chassis ground you should be good...

that said, I still always discretely ground anything that is computerized or electronic in nature... and then I tested..

say I ground lights, fan motors, and such to the body I would turn everything on and check for ground potential between the battery Minus and the ground point where my major devices are grounded.. I should see negligble voltage... if I see vo,tage i know the ground is not good under load... I also would do the same while driving and make sure i didnt have intermittent grounds as I hit bumps and flexed the car..

granted a bus is much larger and likely much tougher to test.. but the concdept is still similar..

the reason i always grounded all of my computers and el;ectronics the same place.. is that oftentimes those computers share comms loops and such between them.. those comms loops are often voltage sensitive... sensors for say temp, oil pressure, etc i always boiught the 2 wire version as engine grounds are notorious for being bad.. esp if aluminum is involved...

-Christopher

[Scooternj]

Originally Posted by RHOMBUS

Speaking of LEDs, scooter, I plan on every last light on the bus, inside and out, being LED. Would it be bad to ground them to the chassis like normal lights?

The tail light's I'd initially gotten had a ground pigtail to use one of the screws for ground. But it shouldn't be too difficult to run a ground wire to chassis

[RHOMBUS]

I'm definitely paranoid about grounding since before I took everything apart, there were ground wire issues affecting the computers. For ground to the body, chassis and motor, I have taken everything down to the bare metal, used dielectric grease and sealed with multiple coats of paint and rubberized material. I am also cross grounding the body to the frame in several locations.

What is a ground loop?

[Scooternj]

Originally Posted by RHOMBUS

What is a ground loop?

This

And/or

This

[cadillackid]

a ground loop can easily happen if you "spider ground" where you ground aimlessly at various points ..

most often in a vehicle there is a Main ground to the chassis and then the body has a connection to the chassis.. most often then for body systems like lights, heaters, etc.. they get grounded to the body metal itself...

for chassis systems.. (engine, starter, solenoids) they get grounded to the chassis.. sometimes there are shared grounds in the form of engine sensors that go to the computer (newer vehicles).. the computer most often is then one of the grounds you see at the chassis going direct to the main computer..

biody sensors for climate, temperature etc usually have 2 wires.. as they need "reference" ground.. which means their ground '0' needs to be the same as the computer..

in the scenerio i mention, there is only one path to ground for any given point..

when you start running wires everywhere.. there can be m,ore than one path to ground... and also induction can occur creating a non-zero voltage reading from ground-to-ground.. (ie measuring ground in 2 places should always read 0 if all is good).... by that I mean place the red and black leads of your meter on ground at 2 different places in your bus... you should always see 0 volts or very close to it..

a more proper way to "fix" a broken ground would be.. lets say you want to have separate ground for a heater motor.. you wouldnt simply run a new ground to the heater and attach it to the existing ground lug (going to the heater frame).. you would lift(disconnect) the ground wire completely off the frame and connect your new wire to the ground terminal of the motor.. and your new ground would be run back to the central spot or ground-bar where theres still only one possiblke ground path for your motor...

-Christopher

[RHOMBUS]

I guess I need to read more about it then. I am pretty confused now. Wouldn't all of the existing little ground wires from each and every light cause the "spider" effect and make a loop?

If I add several ground straps from the body to the frame, am I creating a ground loop then?

My thinking was that every piece of metal in the frame and body was basically a giant negative wire, with the return flow essentially taking the most direct route to the negative post of the battery, through bolts and welds and whatnot.