Radiator questions

skullone · Post by **skullone** » Wed Dec 27, 2006 1:08 am

I have an 84 SR5, with a broken radiator (just bought the car too, doh).
I've been to a couple junkyards and all the radiators there have transmission coolers for automatics.
Mines a manual, so I dont have the inlet/outlets for the transmission on my broken radiator.
Can I use a radiator with a transmission cooler in it anyways? I can't seem to find one online without one either.

keith · Post by **keith** » Wed Dec 27, 2006 6:47 am

All replacement radiators have AT coolers built in. You can use them with a manual.

Iain · Post by **Iain** » Wed Dec 27, 2006 7:26 am

Can we use the trans cooler part of the rad for an engine oil cooler?

coltarms · Post by **coltarms** » Wed Dec 27, 2006 9:34 am

All replacement radiators have AT coolers built in. You can use them with a manual.

You could use them with a manual transmission, but how would you get the fluid circulationg through the radiator? Also, MT's generate far less heat than AT's due to the lack of a torque converter, and therefor the oil will usually last a lot longer before breaking down due to heat. MT oil is also usually tough stuff in it's own.....

Can we use the trans cooler part of the rad for an engine oil cooler?

You could, but again it is not really necessary. ATF coolers are used because the AT generates lots of heat (torque converter.) As this heat has no where else to go other than the tranny and it's fluid, the heat damages seals and breaks down (burns) the fluid. Burnt fluid can also do unhealthy things to a tranny. Seeing as we really don't want to change our ATF every 3k miles we want to make it last a long time. Cooling this fluid by transferring the heat load of the AT to the air via a radiator can help prolong fluid and transmission life. Engine temp, on the other hand is "controlled" by the thermostat. Oil travels around the engine, providing lubrication and absorbing and spreading heat. Coolant travels through the engine head and block sucking this heat out of the metal and transferring it to the air. Thus, the engine oil is cooled. And we change it every 3k miles anyway.

The reason off roaders (and bigger tranny's) use ATF fluid coolers is because of all the idling we do. the AT torque converter is like a friggin heat gun when it keeps slipping at these low rpms. Running engine oil through a radiator would probably be nice during this idling, but is still not really necessary. A good clean engine coolant loop and radiator fan is a better thing to have. However, for the sake of argument (and this thread) lets say one is going to use the ATF coolant loop for engine oil. One would need to install some sort of oil bypass. This would be a great time to install a remote filter setup, too. Heck, just run the oil through some metal pipe on the way to the filter......but I digress..... Anyhoo, set up a remote filter and then run a T from the filter return line (with a thermo controlled valve, cold oil won't really like flowing through a radiator) up to the radiator. A small second pump may be necessary as well....or maybe a stronger sump pump?

Typrus · Post by **Typrus** » Wed Dec 27, 2006 10:43 am

A stronger pump isn't too necessary if you're internal flow can keep up. A big enough diameter (same as the primary oil passages) interchanger will not hold up flow. The filter will do a much better job of that.
Don't need coolers for your engine oil? Oh... Quite on the contrary. Most engine oils out there start to degrade at about 200 degrees F. Most thermostats are set to around 170-190F. Puts that margin pretty close, eh? Well, consider this. The entire bottom end of the engine is ENTIRELY OIL COOLED. The head and the cylinder walls are all that get cooled by coolant. The crank, crank bearings, oil pump itself, and all those good parts are all oil-cooled. Its VERY easy to think that that oil will well surpass 200F in normal operation purely due to the lack of the cooling effect of a circulating, well, coolant.
Look at my moms TDI engine. Came factory with an INTERCHANGER for the oil. Now what is the difference between an INTERCHANGER and a radiator? An INTERCHANGER transfers heat from the ATF, engine oil, or P/S fluid to the recirculating coolant system. An in-radiator "cooler" is an interchanger. If it were located outside of the fluid and transferred heat to the air, it'd be a radiator.
An interchanger for your engine oil is a spectacular idea. It will help keep engine oil and coolant temps close. In a standard-duty car, this is more than enough to ensure safety in the system and longer/more reliable oil life, and thereby engine life.
The real issue with a RADIATOR for engine oil is that its playing a different game than the coolant. It could be getting cooled to say 170 F and recirculating in while the coolant sits at 200. Is 30 degrees that much? Maybe not. But the worst of it is that if you do not have a thermostatic bypass, you know whats happening? You can be recirculating 10F oil into the engine while trying to warm up. That will make things quite hard on the system, as it will take significantly longer to heat it all up.
Now, a good thermostatic bypass, as with the Perma-Cool setup, about 10% of flow will ALWAYS go to the radiator. Why is this good? Well, if none flowed through below a certain temp, you'd have 169F circulating, 20F oil in the rad and pipes, hit 170 and BOOM! Cold-shock to the system. Thats not a great thing by any means at all. With 10% flowing through at all times, When the main circ. is 169F, the rad fluid might be 140F, because it has a gentle recirculation. Hit 170, and you still have a baby jar of 30F but it beats the bloody snot out of our 150F shock.

I think an interchanger, as you are inquiring about, would be a good idea, providing that the piping is sufficient.
On the thought of a remote filter.... Where are you going to put one thats more convenient than now? I can reach the thing easily from top or bottom. If I'm on a lift, I do the whole change under-body. If I'm in my driveway, I just let the oilpan drain into my catch and take off/replace the filter from up top. It can get a little messy, yes, but I like being able to not have to contort to get it to work. Though, it does beat the snot out of our boats setup... Filter is upside down. And its 4x the size of the tercs filter.

BTW, when he asked if it could be used on a manual, I think he was asking if it'd be able to be used in a car with a manual, not on a manual trans itself. Though I'd love to see that setup.

Don't go telling me that a tranny cooler is a bad thing to have if you do more than just off-idle running....
Idling isn't that hard on the TC. Even in D you aren't gutting the thing. Not a massive amount of torque going to it. Want to know where it makes the most heat? In the 100 RPM leading up to lockup. ESPECIALLY in a diesel. Man, you could just watch the temp skyrocketing in our F-250 wonder-truck with the old tranny and old cooler. Thats why the old tranny is the OLD tranny. Our new BTS (Brians Truck Shop... Best Ford E10D and 4R100 truck trannies in the world) and gi-nourmous RADIATOR-style cooler keep the temps tamed even under the harshest TC slip. Which is power-braking for a burnout. Did you know that your tranny temp rises about 7-10 degrees per second while you do that? Its not a good thing to do, even with the cooler-from-Hell.
Point is that during standard towing the temps would rise to a bad state. Even in lockup the stock-style tranny liked to slip up the TC. Not our BTS though. That thing locks and doesn't let go.

Essentially a rule of thumb for all fluid-
If you can keep it within its safe operating temperature at all times, component life will increase by a huge amount.
Typically, the best way to do that is with a good interchanger or radiator style of cooler with a good thermostatic bypass.

Speaking of P/S fluid... It is ATF in our cars. And man can it ever get hot.
Most of you know that as you compress something, its heat increases, right?
Well, imagine the P/S fluid going from room pressure and temp and being compressed to about 1000PSI. The pressure rise is immense. If you know that the discharge air off of a turbo spooling 27PSI or so (stock Powerstroke high-end essentially) can hit over 200F from an ambient of 70, imagine an increase 33x-ish as much. Now imagine the associated temp increase. It isn't as massive as air, but its still significant enough to chew ATF down pretty handily.
Anyway. We have metal lines across the lower rad support for feed and return to help cool this off. But the more cooled it can get the better. I'm considering installing a small cooler on mine. If I can find an ATF thermo-bypass I'll install it too.
Just remember that the pressure line should NEVER be tampered with. It hold sometimes over 1000PSI. Not to be taken lightly. However, the return line from the rack to the reservoir is usually around 30PSI or so.
So how does one differentiate? Easy. Look for the line that is clamped on (return) versus the one that is screwed in (feed).

keith · Post by **keith** » Wed Dec 27, 2006 11:15 am

Couple of minor things here. If you ran the MT oil through the radiator heat exchanger, you would actually heat up the oil, not cool it. ATF is subject to a lot of heat build up as noted. But, ATF needs to be warmed up to a certain temperature for the transmission to operate properly, so if you use an external ATF cooler, you still need to route the ATF through the radiator after the external cooler and before the transmission. If the ATF is not warmed up, many modern automatics will not lock the torque converter.

Any oil that meets specs (SAE) for modern engines will not start to break down until 300 degrees. Synthetics can go to 450 and higher. But oil temperatures in modern engines can go well over 300 degrees. Typically it runs 305. The thin film of oil left coating the engine parts and passageways when the engine shuts down can reach 400 or higher, because it has to absorb all the residual heat and no supply of fresh oil coming behind it. Some of the new Toyota engines reach even higher oil temperatures after shutdown and that is why they are prone to sludge build up. Pumping this oil through the interchanger would probably not help a whole lot, I'm only guessing here because if it did, I'm sure there would be a lot of people doing it vs. getting an external cooler.

The reason for remote filters is capacity. Most remotes have larger of dual filters. IMO, these are a waste on modern sealed engines, the filters just don't have that much to do, and the larger they are, the longer it take to build oil pressure on start up. They have a place on racing engines though.

Typrus · Post by **Typrus** » Wed Dec 27, 2006 12:18 pm

I don't think a dual standard filter is needed. However, I like bypass filters. Most only route a small degree of the oil through themselves at a time, I don't know exact # but I'm guessing 10-20% of flow. They do an INCREDIBLE job of getting the fine garbage out, especially in diesels. Most diesels will turn the oil black in 100 miles from soot. With a bypass, I've seen them go 2k before they start smudging up. The best thing about a bypass is that if you have a proper oil (Schaeffers or Amsoil for instance) you can go 10-15k between oil changes. You'll have to change the filters before that, but the oil will last.

I think the main reason people don't talk about interchangers is, again, because they are great for stock-esque setups. Most people don't bounce around the web bragging about the things they've done to their near-stocker. Except for me. And a lot of the TDI community. That, and interchangers specific to oil aren't around all that much. Again, amongst the TDI community, they are everywhere. Mostly because that is the VW-families choice of cooling, so people will take a V10 TDI interchanger and put it on their 1Z 1.9L I-4. Helps keep oil down to 190-200F. The guys pushing 300HP out of their 1.9L I-4 TDI's (that came factory with between 90 and 110) usually use a combination of interchanger and radiator. It first passes through the interchanger, then the rad, then back into the system. For track purposes, that system works great.

Our tranny cooler setup uses the interchanger FIRST then the cooler. Why? Ours has a thermostatic bypass setup to keep it within operating temp. I don't remember where we bought it, but it was everywhere in their description- It is highly recommended you use a bypass, lest the tranny get too cool and override TC lockup. So we went with the Thermo-Bypass. Have yet to see issues with it. It hovers nicely around 150-170F post-coolers now.

coltarms · Post by **coltarms** » Wed Dec 27, 2006 12:54 pm

I have a new 3core radiator for my Jeep. It also has the 2nd circuit built in for ATF or whatever I feel like running through it. I was thinking about hooking up a small external hose and pump and running water through that 2nd citcuit for a "camp shower." Gets awfully dusty on those trails.....

skullone · Post by **skullone** » Wed Dec 27, 2006 1:30 pm

Through all those answers, I was able to sum up that I can use a radiator with the automatic transmission cooler inlet/outlets on it, with my manual trans. Ill just plug up those lines, or turn it into a water heater for a shower like Coltarms

I just didnt want compatibility issues, since my terc currently doesn't have those lines at all.
Also, are new replacement radiators made out of aluminum nowdays?

coltarms · Post by **coltarms** » Wed Dec 27, 2006 3:22 pm

Oh....

I thought you were referring to using the radiator to cool the MT oil.

You are right, the answer to your question is yes you can use that radiator on your car. And yes, plugging those ports if you're not gonna use them would be a good idea.

Dunno if the Terc puts out enough heat or if the ATF circuit on a Terc radiator would be enough to heat water for a shower, but it sure beats cold creek water.....

Typrus · Post by **Typrus** » Wed Dec 27, 2006 4:56 pm

You'd create an influx of cold into the system and might shock the block a bit. (shrug)
Heh.

coltarms · Post by **coltarms** » Wed Dec 27, 2006 6:16 pm

There are kits available for purchase for Jeeps that do the same thing. Only issue is the kits cost mucho bucks. The aftermarket kits replace the radiator top hose with a heat exchanger that transfers the heat of the coolant to water that is pumped through and out of a little shower head. Figure the ATF loop on the aftermarket radiator would do the same thing for less money. Shouldn't "shock the block" any more than hitting a puddle.

The thermostat should compensate the engine for the heat loss. Bear in mind that my Jeep is a 4.0L I6, not a 1.5L I4. I dunno if the 1.5 would generate enough heat at idle to still be able to maintain engine temp AND heat water for a shower. The coolant MUST be flowing through the rad to allow the shower water to heat up, therfore the t-stat must be somewhat open.....

Typrus · Post by **Typrus** » Wed Dec 27, 2006 6:39 pm

Sure it could. Just set the carb all the way to the rich side!
lol
True enough.

skullone · Post by **skullone** » Wed Dec 27, 2006 6:50 pm

Just ordered a radiator from RadiatorBarn, after reading a recomendation on these forums about them.
Radiator + shipping = $112
Has a lifetime warranty against defects too, should have it by Monday or Tuesday.
Coltarms, wanna come help install it?

Typrus · Post by **Typrus** » Wed Dec 27, 2006 6:55 pm

Oh yeah. Its unlikely that a replacement rad would be aluminum. Aluminum rads are usually a good bit more expensive for our cars at least.