Engine heat management

[etbadger]

Last fall I installed an electronic gauge set that can display the various temperature sensor values in the engine and transmission, as well as an exhaust gas temperature probe (EGT) on our `05 diesel.

In a test drive after doing this I finally saw how hot everything was getting. A 20deg F day while driving up a hill at about 40mph had the transmission temperature hit about 205deg, the EGT got up over 1000deg, and the engine temperature was about 220.

This seemed quite excessive, and a quick check of our power-steering fluid (which doesn't have a temperature sensor) revealed definite burning.

That data, coupled with the consideration that often we are driving very slowly in hot temperatures (think Moab trails in the summer) would tax the cooling systems even more (no airflow, hot air for cooling, etc).

The contributory issues appeared to be many: First the transmission cooler is tiny (1/6 the size of the one in the F350 of same vintage), and located right behind the FORD emblem on the grill. The power steering cooler is tiny. We have an Aluminess bumper which blocks the lower 1/3 of the radiator stack for AC, coolant, and intercooler. Finally, the van engine compartment is packed and cramped, with nowhere for incoming air to go, so this builds high-pressure in the engine keeping cooling air from flowing through the radiator stack as easily.

The solutions we chose were these: Remove stock grill and replace with a relatively sparse metal grill for more airflow. Trim away all of the excess bracing and plastic around the radiators that we no-longer need to allow more airflow. Replace the transmission cooler with one over 2x as large. Replace the power-steering cooler with the old transmission cooler. Put louvers on the hood and quarter-panels to let hot air out. Auxiliary electric cooling fans mounted to both the transmission and PS fluid coolers, and triggered by thermal switches mounted on the intakes to the coolers @ 180deg.

I have seen some folks put a scoop under the front bumper to pull air up into the lower part of the radiator stack at speed, but this won't work for us as we currently have an extra cross-frame member here for rigidity and holding a front receiver. Additionally this won't do much when the forward speed is just a few miles per hour, which is when I think we are probably torturing the cooling systems the most.

Here is a view of the front of the van with the new transmission cooler (left), and steering fluid cooler (right). Also note how the lower 1/3 of the larger coolers would be covered by the front Al bumper.


And here is a view of our hood and quarter panel with the new vents and grill in place.


After putting all of these changes in place I did a test drive on the same hill on a 10deg warmer day and found the transmission temperature just sat at 170 (the thermostat temp), the EGT never exceeded 950deg, engine was at 205deg, and the power-steering fluid hit a high of 80deg after 30 min of in-town driving.

At a pull-off on the road I hopped out and could feel hot air gushing out of all 4 of the louvered vents.

More pics & details at our webpage http://www.badgertrek.com/sportsmobi...l#Transmission

-e

[scatter]

Good write-up Eric. Where did you get the louvers/vents?
I was concerned that increasing the size of the trans cooler would just add more heated air to the engine radiator, but from your tests that doesn't seem to be the case. Or maybe it's just able to get out better. Thanks for taking the time to write this up.

[saline]

Nice writeup! BTW, where did you get the vents? Particularly the side vents.

[etbadger]

The hood louvers are a set from http://www.raceace.com/ which almost exactly fit the structure of the hood (size large). The side louvers are a set from an early 70's snowmachine (Arctic-Cat Cheetah or Panther '73 I believe) which had the proper curvature and the right size and shape to avoid some of the internal structure in the quarter-panel.

To address your concern about a larger transmission cooler: The transmission is going to generate the same amount of waste heat regardless of how large the cooler is. Eventually the transmission cooler will achieve equilibrium with the airflow over it and stabilize the transmission's temperature, however the smaller the cooler the hotter the transmission fluid will be at this point. Thus, the same amount of heat-per-unit-time will be extracted from the cooler and flow over the rest of the stack (minus a little bit radiated from the body of the transmission/pan). In one case you have a stream of very hot air over a small area, in the other the air is not as hot, but covers a greater area. I chose to go for the setup that keeps the transmission fluid colder. (in the real world the larger cooler WILL generate a bit more back-pressure on airflow through the radiator stack, but I don't think this is terribly significant, especially with the way I mounted the cooler offset to the side in an area that use to have solid plastic baffles).

-e

[carringb]

I have the same transmission cooler, and still have never had my coolant temp hit 210F, even pulling 12,000 pounds up Cajon Pass in 110F weather.

[Greggd]

I wonder why these stamped units would be so costly ? We had three different sized Aluminum Vents that approximated these specs and dimensions that we retailed for under
$5.00 apiece , these were also applied with SS Screws and Rivets . We now use an injection molded HDPE for the screens/vents . It really seems like a good solution though .
Greggde

[saline]

Thanks for the vent info. Now where the heck can I find a 1973 snowmobile for the vents. Time to start looking.

[etbadger]

eBay. Here's one like I used in this listing.

I also ended up with a couple of these, which look like they would work, about the same area, but I ended up with 2 RIGHT side ones instead of a left & right.

I cleaned them up, sanded, and painted them satin black to match the rest of the van trim. After trimming the quarter panel I painted the visible area inside the "cheek" of the van in flat-black.

-e

[Greg In Austin]

E,

Two things ...

One, thanks for the great writeup and testing.

Two, it is great to see you back!

How is the family?

.

[Ford_6L_E350]

I wonder if the vents off a late F350 would work if you machined off the F350 part and then painted it? The size looks about the same.

Mike