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Can I use my transmission cooler for engine oil?

Old 12-17-2006, 05:14 PM
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Vlocity
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Default Can I use my transmission cooler for engine oil?

Hello all:

I converted my automatic car to a 5 speed some years ago and still have the stock radiator with an automatic transmission side.

While I haven't had any overheating issues since my twinscrew install I'd like to take advantage of any additional capacity that I can.

So, my question is; would it be possible and advisable to make an extra set of lines and use the transmisssion cooler side of my radiator for additional engine oil cooling?

If the above is possible, would I sacrifice the water cooling ability of the radiator by adding back in this extra load.

Thanks,

Ken
Old 12-17-2006, 06:31 PM
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marton
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would it be possible and advisable to make an extra set of lines 
and use the transmisssion cooler side
Looks like a good idea. I assume you would run the oil through the first cooler & then through the second cooler and then back to the motor? I do not see any other easy way to do it?

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would I sacrifice the water cooling ability of the radiator
I do not see why it would make a big difference, radiator is designed to cool the transmission as well as the standard engine.

Marton
Old 12-17-2006, 06:40 PM
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Thanks Marton.....
Yes that is exactly what I envisioned.....not much of a run needed for the lines.

Thanks,

Ken
Old 12-17-2006, 06:42 PM
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Oil cooler hoses to rad are larger than trans. It is possible to slow down oil flow.
Old 12-17-2006, 07:17 PM
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RyanPerrella
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If you have a twin screw I would find a way to pump the gearbox fluid through that cooler, similiar to the GTS cars. You already have hardlines running on the underside of the car, you would need to find a location to pull from the G28 box amd likewise to return to, (although You could probably use the front drain plug and the top, breather area as your return) and get a small electric oil pump. You wont have the efficency of the GTS unit as i believe there are squirters directly onto the gears but it would increase your transaxle capacity by nearly 2L and would be great if you drive the **** out of it.
Old 12-17-2006, 07:19 PM
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Oil cooler hoses to rad are larger than trans. 
It is possible to slow down oil flow.
Never saw an auto oil cooler; I have a manual.

I copied this picture from the Behr site, I hoped it would give dimensions for the engine & transmission oil coolers but there is nothing written. The connections for the 2 coolers look very similar but I do not know how accurate is the drawing...

Marton
Old 12-17-2006, 07:23 PM
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If you follow Ryans suggestion about cooling the gear box and you are still worried about engine oil temp you could always add an extra external engine oil cooler?

Marton
Old 12-17-2006, 07:24 PM
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The fittings do appear the same on my S4. Maybe it will flow normally.
Old 12-17-2006, 07:51 PM
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I tried to do this after converting to a Devek Radiator with no cooler. I bought an external automatic transmission oil cooler off of a 928 and planned to use that as an external oil cooler. The fittings are significantly smaller than that of the oil cooler. Offhand I would say about 1/2 the size. I was worried that this would restrict flow significantly so I went with an external oil cooler with proper sized fittings.
Old 12-17-2006, 07:55 PM
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The restriction is what concerned me also. The fittings on my S4 do look the same, just smaller hoses.
Old 12-17-2006, 08:13 PM
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Good feed back guys.....

I may just go with a MoCal and mount it up front with the heat exchangers for the intercooler.

As for the tranny, if I go with a cooler back there I would probably just mount a cooler in a horizontal position with a small designated fan.

Thanks for all of the replies.

Ken
Old 12-17-2006, 08:26 PM
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The radiator is already cooling the oil since the oil is running through the same aluminum block as the coolant. It has at least some risk of harm, and little to gain.

Before doing any plumbing I would measure the temperature to see if its warranted. Air ducting might be better than a external cooler too.
Old 12-17-2006, 08:31 PM
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if you want an external oil cooler buy the 90+ porsche item. I paid I think $305 for it new, it mounts just below the radiator. Use that for oil. Use the trans cooler above the rad to cool the transaxle oil, or just remove it.
Old 12-17-2006, 09:04 PM
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"The radiator is already cooling the oil since the oil is running through the same aluminum block as the coolant. It has at least some risk of harm, and little to gain."

Danglerb
I don't understand what difference this would make as one "end" of the radiator is already circulating engine oil. I would be employing both "ends".


"Use the trans cooler above the rad to cool the transaxle oil, or just remove it.

Ryan
The cooler is integral to the radiator and not an external cooler.
Old 12-17-2006, 09:56 PM
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Oh,

Is the cooler above the radiator and below the intake ducts one piece with the radiator assembly? I didnt know, manual cars before 92 dont have that. I figured it would be a different part.

Regardless, I wouldnt run oil through it, your radiator is your oil cooler it runs through a tank inside the end cap of the rad. If anything you would reduce circulation of the already effective engine oil cooler and also have the potential for more oil leaks with the additional lines you want to run.

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