2400cfm trans cooling fan?

[booster]

Sort of!

Transmission temp issues come up pretty regularly with the Chevy based class B's, and secondarily, engine temperature problems. They are intimately connected as all the cooling goes on in the radiator, oil, water, trans fluid. The only available auxiliary cooler is the factory add on trans cooler, unless you go aftermarket stuff.

We already had added the trans cooler, but others had mentioned they still got hot with the cooler, so I decided to add a fan to it. The cooler is of good design, plate and fin, but fairly small, so an add on fan would block a lot of it with its motor. The small fans also are on such a small diameter, the airflow isn't the best.

The stock trans cooler sits off of the AC condenser by a bit



Very near the center of the condenser



I decided to try to kill two birds with one stone and get air to the trans cooler and also more air to the radiator to cool the oil and water. I picked up a Spal 16" pusher fan that is rated at 2400+cfm (at 0"). It comes with mounting straps, and I bought a rubber pad/gasket that fits on the output side to cushion the condenser and keep the blades from hitting it. I took off the cooler brackets, and it moved very readily, so I could move it about to get the best new mounting position.



I mounted the fan with the two straps up to the radiator crossmember, and another down the passenger side to the frame below.





The fourth mount, for the inboard bottom goes down through the plastic shield to the lower cross frame of the van



The cooler goes back in place, overlapping part of the fan, so it will get forced air. The original brackets were modified to tie it to radiator crossmember on top, and to the plastic shield on the bottom.



What is looks like finished



And from the side



The fan will control from a temp sensor that comes with the Hayden relay control I got. It is made to go into the fins of a radiator, but I will silicone it to the back side of the trans cooler. The relay control has adjustable temperature capability and will mount in the engine compartment. I will also have a manual switch in the van, so we can give it head start at getting cool, when we are coming up to a big climb or stop and go traffic. Hope to wire it up tomorrow.

The mechanical fan in the van is probably doing about 6000cfm at 1500 and over engine rpm, so the 2000+ from the electric fan should be significant. It pulls a piece of paper tight into the cooler and with the engine not running, and it blows quite a lot of air through the condenser and radiator, into the engine compartment.

I am also going to get some dense styrofoam insulation and block of the openings the let air, coming in through the grill, to go out under the van without going through the radiator. I will leave a bit of opening on each side to let some air into the sides of engine compartment, by the battery on one side and the fusebox on the other. That should improve cooling while moving.

Hopefully, this will all be worth it if we get into the mountains and Alaska.

[Mike]

What would some sort of a stone deflection system do to the air flow throughput,
assuming you're headed to Alaska at some point?
Apparently the (loose gravel) roadways are notorious for damaging rads and windshields.

Also, did you consider changing out the rad for a new one before adding the fan mod?
I can't recall what year your chassis is, sorry.
If you ever need to replace it out in the real world, what will a rad shop say about it, or
would you do your own replacement?

Nice mod, btw.

[booster]

We have thought of the stone protection, but it probably would only work in cool weather, as we would put a screen across the grill that would reduce flow. Probably would try if we get on a lot of gravel.

We have an 07 C190P, and there are not many options for a radiator change. If they add core thickness (nor room anyway) it restricts airflow, which is a big issue with the vans anyway, getting the air out of the tight engine compartment. No room to go wider with the radiator.

The only way I know of to increase the radiator capacity readily, to cool the water, would be to add fan cooled trans and oil coolers under the van, on the frame. Then you wouldn't be putting all the trans and oil heat into the water of the radiator.

I am hoping that by boosting the air, and closing off some of the areas that the air can "leak" to instead of going through the radiator, it will be enough. I also have room to add another fan (14") on the other side of the radiator, if it doesn't give enough.

Folks seem to have the trouble only on long climbs, in hot weather, fully loaded, or in stop and go traffic when it is hot, so it isn't a severe problem, just under some conditions.

There is always the ace in the hole of running the heater full blast, which is amazingly effective. The problem with the Express vans is that the AC runs in all positions (don't want the AC on if you are running hot) of the heat control except floor and vent, so blows right on you. We changed ours, so we can shut the AC off in all positions, if we want, so with the heat on full through the defrosters, it will go right out open side windows (most of it anyway).

We have found we really like the fresh air, no AC, coming out of the defrosters when driving in moderate weather, as it is less drafty and you don't have a lot of hot air coming down off the dash.

[markopolo]

Originally Posted by booster

....................There is always the ace in the hole of running the heater full blast, which is amazingly effective. The problem with the Express vans is that the AC runs in all positions (don't want the AC on if you are running hot) of the heat control except floor and vent, so blows right on you. We changed ours, so we can shut the AC off in all positions, if we want, so with the heat on full through the defrosters, it will go right out open side windows (most of it anyway).

We have found we really like the fresh air, no AC, coming out of the defrosters when driving in moderate weather, as it is less drafty and you don't have a lot of hot air coming down off the dash.

Brilliant idea. Maybe a new topic for Tweaks, Mods & Projects if you get the time.

[Mike]

I know what you mean about the under hood engine compartment air having few intake/egress routes.
The whole Roadtrek design has issues dissipating heat from underneath, with the additional skirting
and external storage compartments. Both engine and exhaust heat from routine driving is trapped
underneath the vans. If there's a breeze when you stop for the day, it's less of a problem. Or, if you
camp routinely in cooler climates, it can be a bonus. However, when you stop for the day and it's hot
and humid and the air is still, it's a problem.
Then there's the placement of the generators under the sleeping area. I realize there aren't many
options there, but perhaps moving the fresh water and holding tanks aft and moving the genset
forward might help. It sort of defeats the purpose by the positioning of the generator under the rear
end of the van so that if you're dry camping and want to run the A/C to cool you, you have to fire up
the generator right under the bed, which generates heat which just sits under the floor under the bed
with nothing to move it along.
It's a problem in any small footprint RV. Some of the bigger rigs can place their gensets forward, so it's
less of a problem.

[AZ ADVenturist]

I've been concerned with this heat "trap" issue under the hood of our C190V R/T.
On long drives, especially leaving Arizona - I've gotten into the practice of leaving the hood unlatched. Secured by the lever hook only & two rubber bungies hooked onto the center grill support. It all stays in place with no bounce or rattle. Gives a sorta' Ram Air effect (I Hope).
The temp. gauge rides a little lower and my imagination convinces me that we gain 1 or 2 mpg. Then when we arrive at the evenings destination I open the hood (or is it a bonnet - eh?) to dissipate all that trapped hot air & let 'er cool down.

I like the trans. cooler & fan setup. Not sure I'm qualified to do the installation & my mechanic already holds 2nd mtg on the R/T...

[Mike]

Sounds a bit risky, driving with the hood only partially latched.
I find the temp gauge creeps up if we're on an especially steep climb and losing speed as we climb.
I'll usually try to mitigate engine stress by allowing us to lose some momentum, and slow as we climb,
unless it's not safe or may cause more grief by doing so. In warmer weather, it's better to keep our
speed up, to keep air flowing through the grill.
So at that point it can become a catch 22, if you put the hammer down, to try to maintain speed and
air flow through the standard rad setup, it increases the rpms and the engine heat. If it ever got to a
critical point, I'd pull over and let things cool down, but that's not a solution, as you'll eventually have
to start your climb again when you've cooled down, but this time from a standstill, with no inertial momentum to get you started uphill.
I like booster's rig.
I wonder if there might be some way to increase or focus the air flow through the grill into the rad?
Using some sort of deflectors? Or is the factory setup best of breed for overall cooling performance?

[AZ ADVenturist]

Mike; I can't swear that my part'l open hood is effective or not (wishful thinking - maybe).
But it is secure even at freeway speeds.
When we are approaching very steep inclines I take it off Cruise Control so the trans. doesn't keep shifting - down, up, down. I use the foot feed/throttle to try to maintain speed & control shifting, let speed decrease slowly then let it shift down - at about 55 mph. I do shift Down for long/steep descents to save on braking (some).
We also turn off Air Cond. (even in Arizona or Mojave Desert). Before we start a climb.
It's a little different technique than driving my Honda Accord. But seems to work for me.
Ric.

[booster]

Originally Posted by Mike

I like booster's rig.
I wonder if there might be some way to increase or focus the air flow through the grill into the rad?
Using some sort of deflectors? Or is the factory setup best of breed for overall cooling performance?

As I mentioned in the earlier post, the grill/radiator opening setup is not ideal for forcing air through the radiator and engine compartment. When you have the grill out, you can see lots of openings, other than the through the radiator, that the air coming in through the grill can go. Of particular interest are the ones that open down towards the road, for a couple of reasons. Obviously, you would rather have that air go through the radiator and engine compartment before going out the bottom. If the front air dam is low, like a Roadtrek with bumper covers, and doesn't have too many openings, it will block the low air going under the van. Air going down the side of van at road level will pull a vacuum under the van, so if most every route for the air is blocked, except for through the radiator and/or through the engine compartment, the vacuum will pull air through and help the cooing. That same vacuum will rob air from the radiator if there are opening between the grill area and the ground. I plan to plug up all those areas with the dense, pink foam insulation to see how that works. I may also tape up all the middle openings of the front bumper cover to help it pull vacuum better. I will leave the outside openings clear so air can get to the brakes.

AZ, a very common trick in the world of hot running muscle cars is to remove the rear hood seal strip that seals the back of the hood to the engine compartment. When you are sitting still, it allows hot air to go its natural way (up), and when you are moving it will push air into the engine compartment as the windshield base is a high pressure area at speed. Depending on how well the air can get out of the engine compartment at speed, it MAY reduce the air through the radiator by a small amount.

I am hopeful that the single fan will be plenty to keep us cool (with the heater in reserve), along with the blocking of bypasses, but we could still add another (14" this time) fan to the other half of the radiator. We should be able to get a good read on how it works by watching the trans temp on the Scanguage, as it always goes up before the engine temp for us.

[Mike]

Ric: I do that stuff, too. There is also a suggestion that downshifting out of O/D is a good idea.
I've got a scan gauge and have engine load as one of my regular displays. My 2002 downshifts
around 37-38% load on the engine. So I can better predict the degree of difficulty the van is
experiencing as we head up a hill, and deal with it that way.
booster: I still haven't figured out the transmission temperature display for my unit and
year/make/model, but I think if the water temperature begins to climb, the transmission is
probably already there.

It's funny about folks who regularly drive in the southern States. If they go for a drive in the
summer heat, it's not unusual to see hoods popped and opened up at rest areas and other short
stop points like shopping mall parking lots. A couple of years ago, we saw a large GM pickup truck
with a large number of occupants at a Walmart in WV, early morning, cool in the 50F range with the
hood up to let air flow through the engine compartment. It struck me as odd at first, and I wondered if
they needed help, but then the lit up. They were doing it probably out of habit.

[booster]

All the parkways and hills. although not the Rockies, and not very hot (70-75 degrees) let us get some testing on the added fan setup.

With the fan off, in general, the temp would climb farily quickly to the 200 degree range on the water and transmission (didn't let it go further). During that temp climb, if I turned on the fan, the climbing would very quickly stop where it was and stay there or go slowly down. If I turned the fan on before any climb in temperature, we would rarely see much above 195* water and 185* transmission. The exception was when we had an over 2 mile twisty climb up a mountain to a lookout point that was 20 mph in second gear at about 2500 rpm. The fan did not stop the temp climb on that one, just slowed it down a bunch. Reached 205* water and 200* trans on that climb.

Bottom line is that the fan helped a lot, but did not prevent heating completely, so I think I am going to put in a second fan, and do the air bypass sealing mentioned earlier, to see if we can get a bit more benefit.

[peteco]

Originally Posted by markopolo

Brilliant idea. Maybe a new topic for Tweaks, Mods & Projects if you get the time.

Agree. Please describe this mod. Thanks.

Pete
2006 210P

[booster]

The only really difficult part of modifying the AC to add an off override is getting the Chevy dash apart to get at things, but you may be able to avoid that step. In our case I had to get the dash apart to get to the heater controls out so I could see how they were built and wired, but now that it is known how they are done, you may be able to just find the appropriate wiring elsewhere in the harnessing.

The heater control is the plain old school variety of a knob control that has brass contacts around it at the various conditions. Individual wires go back to the control module (I think in the BCM) to set the functions. The output that says run the air conditioner is on long contact that is active on all the positions except vent and floor heat. The output from that contact is a single wire, green IIRC, that comes out in the harness to the module.

ALL you need to do is put an on/off switch in that wire and you are done.

I was afraid the BCM would be monitoring something and not like that being done, but there appears to be no affect at all, except to be able to turn the AC off in all the positions, like defrost, or bi level, that the it would normally run.

If you decide to do the mod, let me know and I will go back into the manual to confirm the wiring so you could try to pick the wire up easier.

This has been one of our most used and favorite modifications to the van.

[Bruceper]

You might want to try a product called Water Wetter

http://www.redlineoil.com/Products.aspx?pcid=10

We use it for racing in small water cooled engines and it really does work. Due to it being racing, ONLY water can be used in the cooling system, no glycol. Saying that however we have tried it in our regular vehicles and it does give a little help.

[booster]

Originally Posted by Bruceper

You might want to try a product called Water Wetter

http://www.redlineoil.com/Products.aspx?pcid=10

We use it for racing in small water cooled engines and it really does work. Due to it being racing, ONLY water can be used in the cooling system, no glycol. Saying that however we have tried it in our regular vehicles and it does give a little help.

I have used Water Wetter in the past, in our twin turbo Challenger, which was "cooling challenged'. We saw a very small improvement in the cooling, but not significant, and with iron block and aluminum heads, we needed antifreeze besides here in MN. The Challenger turned out to be airflow related when finally corrected.

Gut feel is saying the van is also has airflow issues, especially since the single fan made a noticeably positive difference. I am hoping the second fan, plus eliminating the ways air can go around the radiator without going through it, will help a lot. I do worry about the underhood temp rising, though, if I force more of the air to the radiator instead of going through cool.

[Bruceper]

I did not mean to advocate not using glycol in any way in an automotive engine. I was just trying to state where my experience with water wetter came from.

I'm in Winnipeg, and just like anywhere in Minnesota if you don't have antifreeze, you will no longer have an engine block that's in one piece. But the water wetter may offer some assistance with glycol and keep 5 degrees off. Anything helps.

[Mike]

I just googled water wetter to find out more about it, and there was a "problem" hit in the list. Read a few anecdotal blogs and threads and the one most often mentioned was a brown sludge deposit in the cooling system. Suspected to be some sort of reaction with old coolants or simply the breakdown of the product itself or it's components over time. The manufacturer was contacted about it, according to some posters, and they suggested it was normal.
FYI?

[booster]

I finished up putting in a second 16" fan which is a tight fit, but works fine. Trans cooler sneaks in between them without any tubing modifications.

While I was at it, I decided to fix up some of the older add on wiring that included a lot of splices, inline fuses, etc.

Went to fuse taps in the main fuse block:



Added a small fuse block with its own power and put the fan relays next to it:



Put the temp sensors on the outside of the top radiator hose with a piece of rubber sheet to insulate them. Crude, but I don't think I will ever have the fans on automatic:



The two fans and cooler:



This is with the fans running, engine off so no engine fan pulling and low voltage of only 12.2 volts. That is a piece of heavy printer paper, I am holding the far edge out of the pic. The fans will pull the paper flat to the cooler from nearly a foot away.



As long as I was wiring, I put in a 300 amp digital ammeter so I can see how many amps are going to the coach from the big alternator conversion. The meter is to the right of the two fan switches in the dash:



This is the inductive pickup for the ammeter in the lines to the coach from the separator:



Now on to sealing up the air bypasses around the radiator.

[booster]

For trying to get better control of airflow and road splash, I started by adding splash shields to the front of the front wheelwells, that were totally open to bumper and up into the radiator area.



There have been times when we came off of gravel roads onto blacktop that we saw rocks coming off the front tires and actually going out ahead of the van, so we know stuff flies forward a long ways.

I started with a cardboard template, cut and tape version.



This is with the semi rigid, .090 ABS plastic in place, and with a small piece of rubber splash shield material to fill the upper corner.



Cutting the ABS with a Stanley knife is pretty tough, as is using a jigsaw or regular tinsnip. I decided to try the old HVAC slot cutting snips I have. They have two cutting edges so they cut a strip out of the piece. That way they don't need to bend the sheet in any way. They worked really nicely.

[booster]

After the wheelwells, I moved to the inlet area of the radiator, which had huge areas that the incoming air could go through instead of going through the radiator and cooling it.

To the sides:



To the bottom:



I added seals to the sides and bottom including the gap between the bumper and floor of the inlet area:

The sides are like this: (headlight and turn signal lamps block a little when in place, but not much):



Bottom middle:



Left side were bottom meets side at grill mount:



There was also good sized gap at the hood latch where it comes through the grill shroud, and also a gap all along the shroud at the top. Siliconed the top and put a seal around most of the latch gap:



The material I used is the same stuff the factories use for the flexible splash shields, like in the wheelwell to engine compartment sheields. I had looked many times in the past and couldn't find anyplace to get it, but finally found out what it is called, and found some on ebay. It is called masticated rubber (recycled rubber with fabric strands in it) and it is very strong, but still flexible enough. It is about .090" thick, and I could not tear it. It is not cheap, but it works way, way better than anything else I have ever found.

All the sealing is kind of a grand experiment, as I have no idea if it will help, or not. It could even make the engine compartment run too hot. We will see what happens the next time we get to some real hills instead of molehills we have around here.