| Author |
Message |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 10:40 am: | |
I wanted to show everybody the progress I made over the weekend getting some cooling to my V730. Here’s the pics: http://www.brownland.org/bus/4108/trannycool/
If you recall, I was running high temps on the last leg or our trip down to Texas. It turns out that the oil cooler’s fan fuse blew on that piece of the trip. I also discovered that the fan was pushing air through the cooler and right up against the exterior skin of the bus, rather than pulling air through the unit and into the engine compartment, which probably let to the overload condition.
So, I reversed the leads on the wires to reverse the fan flow. Then, I cut a hole in the panel where the cooler sits for intake air, and another in the tranny door for exhaust (hopefully). I covered these on the inside with a decorative aluminum screen from Lowes.
We leave on Friday for a ten-day trip to the Bay Area, so hopefully this will make an improvement to the tranny cooling.
I’ll keep you posted,
Brian Brown
Longmont, CO
P8M-4108A-216
PD4106-1175 |
Cliff (Floridacracker)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 11:30 am: | |
Brian,
Looks good.
There is also a second benefit to the venting.
My 4905 developed an exhaust leak and where the muffler sits is a pocket that can hold the gases so they will rise into the pasenger area if not air tight.
I am going to cut a vent like yours on each side to allow the gases to escape and prevent this if I should ever develop another leak.
Of course I have to cut out the old waste tank too.
Cliff |
Tim Strommen (Tim_strommen)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 1:12 pm: | |
Hello Brian,
Your fix looks good (glad the fan fuse was found too...). I would comment though that the small holes in the type of metal you installed over the holes typically make air circulation hard. A stretch mesh sheetmetal is the type of guard typically put over that type of hole.
Granted - I think the method you chose is suitable and will probably prevent over cooling of the tranny. The bus looks good!
Cheers!
-Tim |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 1:43 pm: | |
Did you actually check fan rotation after changing the leads? Most DC motors will not change direction when the input polarity is reversed.
Richard |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 1:49 pm: | |
Thanks, Cliff. I did have a teensy-weensy bit of concern removing some of the shear strength from the back of the bus (the forward hole). If I need to shore it up with some struct. members and rivets, I'll do that. I sure don't want to crack a bulkhead.
If you keep your holes small, maybe you can get away with it also.
Tim: Thanks for the kudos. Yes, the metal does seem to be more opaque than what is often used (like on the rad.). It does look much better (IMHO) than seeing the tranny and cooler beyond. Once I get her out on the road I should be able to tell if she's cooling adequately. In a pinch, I can remove the covers in just a few minutes.
Standing still, the fan can still suck a piece of paper against the forward mesh hole. The rear hole doesn't do much now... but maybe it will let some of the converter heat dissipate. I could always put a fan on it to suck air out, but it might be overkill until I have some data.
There's also a big slot in the top of my aftermarket rear cap that might let the rad. and tranny heat out (hopefully).
Thanks,
bb |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 1:52 pm: | |
DML, yes the fan does "pull" the air in the opposite direction now (the spec. sheet for the cooler says this is as intended).
I have no idea why this works. But I also installed a similar but smaller 12v fan in my '06 that would reverse depending on leads, and the manuf. directions said to this and turn the fan around in its mounting if you wanted to reverse fan direction.
Thanks,
bb |
Jim-Bob
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 1:57 pm: | |
Hi Brian,
My comment would be the same as Tim's. GM seemed to use stainless steel expanded metal screen for body openings. I'm sure aluminum would work but more suseptible to denting. The expaneded metal will allow several times the air flow.
I would lean toward a self resetting breaker for such an important circuit. But maybe your fuse blew due to a short? If not, maybe it's marginally sized. |
Tim Strommen (Tim_strommen)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 2:12 pm: | |
Further on JB's comment,
Two things: 1) I'd ensure that the wire/fuse size is correct for the current draw of the fan, 2) the overheating motor may have just blown the fuse due to the temps indicating a correctly sized system (in high temps motor winding efficiency goes down nd the power draw goes up - thus the fuse blowing may just be indication that the safety device worked as intended).
A self resetting breaker would be good, but I still like Brian's method of glancing at your gauges every once in a while to make sure everything is in it's place. If something is off, everyone should learn from Brian's correct example of pulling over when safe and taking a good look at what is happening.
Cheers!
-Tim
Edit: Permanent magnet motors can have the coil polarity reversed by switching the power poles. This will cause the motor to turn the oposite direction. Stator/Rotor motors do not care which way they get the power so long as it is there (i.e. both the stator and rotor fields reverse in polarity so the motor will always spin in the designed direction). - Tim
(Message edited by Tim strommen on May 01, 2006) |
JR
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 9:27 pm: | |
Hi Brian,
FWIW, the reason the fan should be turned around is that the fan blades are not as effective running "backwards"...whatever that is. Generally, rad fans are most efficient pulling air thru a rad (oil cooler or whatever) than trying to push the air. Lots of Jap cars push air.
Yours may work either way...your trip will tell.
Good luck, JR
BTW, Now that you have moved up you don't have a dog in this hunt, but finally got a respectable sound level with the Yamaha Genset. Set the thing on 1" rubetex and "floated" the bolts that hold it down. Mounted the air cleaner on isolator mounts. Also moved the muffler under the coach. Soo much better! |
frank-id
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 9:54 pm: | |
The material used to cover the body openings looks small. Maybe some factory or custom louvers would be a nice choise to block view of cooler and fan.
Louvers are always a nice touch. Frank in Idaho |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 01, 2006 - 11:23 pm: | |
Tim,
The wire from the 40A relay to the fan is 10GA. The ground is also 10GA. The actual leads on the fan were smaller, maybe 14GA, but they're only about 8" long before butting into the larger wires. It's a 24v unit, 1200cfm (no clue on draw), but I'm assuming the wiring is adequate. I'm hoping that high temps and stalled airflow caused the trip. When I short the alarmastat to ground the fan comes on as it should.
JR,
Yup the thing now pulls as it was designed (according to literature). I think that the prev. owner just reversed the leads. Like you said, "the trip will tell."
Glad you've had success with the Yamaha "quietening". My experience with the unit showed it was a relaiable, miserly (if loud) genset. When I sell the old '06, I'll let the new owner know about your sound solution.
Frank,
I'll look for something better to go on the holes when I get back from SF. Thanks for the advice.
Thanks all,
bb |