Engine Temperature Management-Trans Circuit Warning many pictures!

[Photoman]

This is part of some things I am doing to try to set up the cruiser to run at a stable temperature. It is not complete and may not be the final way I do it but maybe this or bits of it will help others. The idea in the diagram is not just trans fluid cooling; although that is the main goal, but also to warm the trans fluid at cold temperatures via the radiator bottom tank trans cooler. Oil thermostats in picture two. Other picture is of front external trans cooler. FWIW, the intercooler plumbing has since been finished and powdercoated. I would like to keep the trans temps between 175° and 185° F.

Bill

 

[Photoman]

These are some pictures of the number three and four trans coolers I am making. I am going to try to mount them next to the ABS stuff on my 97, connected to the second snorkel I made. Attached to the snorkel is a bilge fan activated by a temp switch when trans fluid flows to the coolers. Air will dump from the coolers under the cruiser via 3 inch hose. In the one picture it can be seen that I have not welded on the aluminum hose connections I made, since I don’t know the exact locations on the cooler box yet.

 

[Photoman]

Picture showing connection to bilge fan on DS snorkel. Picture of bungs welded in trans pan for return.

Bill

 

[e9999]

very impressive work, as usual.

But why do you want to run the Trans at a relatively high temp? Could you try for a lower temp setting? (IIRC, mine is running at lower temps than that most of the time in town and on the fwy.)

 

[SUMOTOY]

Nice metal work Photoman. A couple of suggestions. Ditch the bilge fan. They are very low output fans, a lot of air pressure doesn't mean a lot of air flow. Most Bilges use either 3 or 4 in ducting, and max at around 200-300cfm.

Try getting a smaller (8 or 9in) aux rad fan, it will flow twice what a bilge does. Then put it behind the box you built, and let it pull air thru it. Get some ducting the size of your opening, and run it to a fresh air source. I don't think you need to spend a bunch of time or expense in doing this, the first aux cooler and the rad will do most of the work anyhow. Just leave the aux3 setup with a thermostat activated fan, it won't turn on often.

Stacking coolers reduces the efficiency of them. You really want to have surface area, not depth, epecially if you have marginal flow. Since these are all series anyhow, but one beside your IC, and the other somewhere down below. If your baseline trans temps are that high, I'd have something sitting in front of a radiator fan, it will get much more direct and fan air than you'll ever blow thru that box with a bilge pump.

Scoop air and or use really big ducts. Limiting ducted air to 3or4inches is ok for a high to low pressure zone (read: brake cooling), but it's not very efficient for coolers.

Also, the RX7 cooler needs a plug to replace the thermostat (between the inlet outlet end cap). Otherwise, you are mostly bypassing the cooler. If it was me, I'd spend my time getting the RX7 cooler ducted. Then find out why the overheat. I don't believe for a second that locking the center diff overheats the trans, nor do I believe that any 80 needs 4 trans coolers!

Still, nice metalwork.

SJ

 

[Photoman]

e9999,

Good question and I don’t know the answer. Maybe Gary would know more on this. I talked to a local tranny guy that has a shop and he said that heat was one of the main tranny killers. Nevertheless, he said it was good to get the fluid temps up at times to burn off moisture. Link1 and link2 with charts showing temperature vs. tranny life. Don’t know if they can be believed or not.
This fluid thermostat opens at 180 ° F so if I use this one I am stuck with that temperature. I have done something like this in the past and used a temperature switch and a solenoid valve, but this seemed easier.

Bill

 

[e9999]

e9999,

Good question and I don’t know the answer. Maybe Gary would know more on this. I talked to a local tranny guy that has a shop and he said that heat was one of the main tranny killers. Nevertheless, he said it was good to get the fluid temps up at times to burn off moisture. Link1 and link2 with charts showing temperature vs. tranny life. Don’t know if they can be believed or not.
This fluid thermostat opens at 180 ° F so if I use this one I am stuck with that temperature. I have done something like this in the past and used a temperature switch and a solenoid valve, but this seemed easier.

Bill

they must be referring to domestic cars since they seem to think that 100,000miles is great...

all I can say is that if my ATF were kept at 180F, that would be significantly hotter than what I'm running now as OEM.

 

[Photoman]

SUMOTOY,

The 3” snorkel I’m using for the intake is dead without moving. If I’m not moving I need a fan. A 9 inch fan would be nice, but it’s hard to get 10 lbs. of air through a 5 lb. hole. I agree the 3rd and 4th coolers will almost never be used, but the two stock ones weren’t cutting it. Also realize with my diagram that the radiator tranny cooler will only see a max. of 180 ° F temperature; in effect cooling the engine by reducing the coolant temperatures if they are greater than this. I realize that stacking the coolers is not the most efficient, but I’m working with a small area and wanted to maximize it. I’m sure you noticed how I ran the fluid into the first stacked cooler then the second one since this is the most beneficial way to run the fluid if the coolers are stacked.
My baseline trans temps are fine. Churning up a mountain through deep snow locked up with a heavy vehicle is where I have overheated the transmission twice.
Could you explain what you mean by an RX7 cooler and the plug? I have a GM cooler in the rad tank, an external Modine, and two external Setrabs.

Quote by SUMOTOY

I don't believe for a second that locking the center diff overheats the trans, nor do I believe that any 80 needs 4 trans coolers!

Pretty strong words. Have any data on that?

Bill

 

[SUMOTOY]

SUMOTOY,

Could you explain what you mean by an RX7 cooler and the plug? I have a GM cooler in the rad tank, an external Modine, and two external Setrabs.

Sorry thinking of clownmidget...

Quote by SUMOTOY

Pretty strong words. Have any data on that?

Bill

Just reason for now. I've seen a lot of offroad trucks, race cars, many built by manufacturers. I have a bro in law that does engineering for GM drivetrain, including the race trucks. For years I've picked his brain, added a few beers, and repeat. I'd be happy to bounce this off him, but I've got good money the data I need, would be under the hood of *your* truck.

I enjoy watching engineering projects, especially DIY. I've doubled up an oil cooler but only once, on my big block yamaha FJ1387 motorcycle. It really adds more capacity, not cooling. I vowed I would never do it again, and haven't. That includes in nacelles a fraction of what's in the LC. I guess it's what you're used to, I find the LC to have acres of room to play.

Good luck with it Photoman, given the project, you have sure made it look pro. It has design and concept flaws, but who am I to judge that? I do think any guy with that kind of metal skills only needs to back up to a few books on airflow engineering, and he'll be king.

SJ