External engine oil cooler

mTk · Post by **mTk** » Wed Apr 07, 2004 1:19 pm

When i had a 4eat i installed an external tube & fin atf cooler. I'd like to use the same cooler for engine oil now that i have no 4eat. I can probably find a sandwich adapter for between the block and filter that i can run hose from.

My questions are, will the same hoses i used for the atf work w/ engine oil? I'm guessing that the engine oil will be under quite a bit more pressure than the atf was.

Additionally, what is the thread size for the oil filter?

MK

mTk · Post by **mTk** » Wed Apr 07, 2004 1:26 pm

If not a sandwich adapter, then i may use a filter relocation kit and run the cooler through the return hose.

MK

mTk · Post by **mTk** » Wed Apr 07, 2004 1:41 pm

Also, i suppose i could use the atf cooler that's built into the tranny.. would it flow enough to be effective for oil?

MK

vrg3 · Post by **vrg3** » Wed Apr 07, 2004 4:26 pm

1) I don't see why hoses that stand up to ATF wouldn't stand up to motor oil. Isn't ATF under high pressure too? I mean, it does operate hydraulic circuits.

2) I believe the filter threads are M20x1.5mm.

3) Someone else who knows better should offer their insight too, but I think the fittings on the radiator's ATF cooler are really small. I don't think it'd work that well for motor oil.

4) Why not use an OEM oil/water heat exchanger? Unless you're making a lot of heat, engine coolant should be able to carry it away. You get other benefits too: the engine warms up quicker, you don't have hoses running all over the place, and the oil changes become easier because the oil filter is easier to reach.

mTk · Post by **mTk** » Wed Apr 07, 2004 5:02 pm

I agree that the atf cooler in the radiator is too small. I would love to run an oem engine oil cooler, but it is probably quite a bit more expensive thatn using what i already have.

MK

vrg3 · Post by **vrg3** » Wed Apr 07, 2004 5:15 pm

If I recall, ciper has an oil cooler from a 91 turbo he's willing to sell. That might be affordable.

Brat4by4 · Post by **Brat4by4** » Wed Apr 07, 2004 6:06 pm

oil cooler cores can be had for $40 or so from www.summitracing.com

DOA · Post by **DOA** » Wed Apr 07, 2004 9:55 pm

If the hose bore on the ATF cooler is much smaller than the main oil lines then youll probably lose oil pressure all through the system due to the restriction but the connectors will almost definately handle the pressure, hydraulic hoses of any sort are way OTT for engine oil pressures.
Also, why are you adding an extra cooler and where are you planning on putting it? If youve got a turbo model then it may be worth running it inline with the turbos oil feed, preferably before the turbo to keep it nice and cool.

NICO · Post by **NICO** » Thu Apr 08, 2004 6:36 am

hot oil can eat any line no matter what it is.

vrg3 · Post by **vrg3** » Thu Apr 08, 2004 2:35 pm

It can be hard to find good high-temperature oil-resistant hose. We were looking when plumbing my brother's turbo oil drain line. I'm sure you can find expensive Teflon hose that's spec'd right, but we're poor so we ended up using some hose that's only rated up to something like 257 degrees F. That was the highest we could find.

Then again, the hoses that came with his oil filter relocation kit seemed to be made of ordinary rubber (no Teflon sheaths or anything), so there may be some rubber formulations out there that would be fine...

DOA · Post by **DOA** » Fri Apr 09, 2004 8:02 pm

Quite what temperatures are you expecting here, the hottest I ever saw it get on my old golf was 105degrees. I accept on a turbo car it may get a bit hotter but much hotter and the engine will be scrap anyway and the coolant will all boil off surely. Oh and whoever said hot oil will eat through any hose eventually, yeah your right, but thats why you maintain your car lol

.

vrg3 · Post by **vrg3** » Fri Apr 09, 2004 8:14 pm

It all depends on where you're dealing with the oil... The oil drain line off the turbo probably has the hottest oil you'll find on the car. The oil that's fed to the filter is probably fairly close to the engine's operating temperature, roughly 100 degrees Celsius.

mTk · Post by **mTk** » Sat Apr 10, 2004 9:33 am

What size are the oil and coolant fittings on the turbo?

MK

vrg3 · Post by **vrg3** » Sat Apr 10, 2004 5:40 pm

Someone please correct me if I get this wrong, but:

Coolant (both sides): 12mm banjo. I don't know the threading on the banjo bolt but I'd guess M12x1.25mm or M12x1.50mm.

Oil feed (head side): 12mm banjo also, same as coolant lines.

Oil feed (turbo side: 10mm banjo, probably M10x1.0mm or M10x1.25mm threads.

Oil drain: 2-bolt flange with gasket. The stock tube that attaches there has an outer diameter of 15mm.

THAWA · Post by **THAWA** » Sat Apr 10, 2004 5:51 pm

on a semi related note aren't our wheel studs 12x1.25?

vrg3 · Post by **vrg3** » Sat Apr 10, 2004 5:55 pm

Yes, our wheel studs are M12x1.25mm. Just like the MT's shift knob.

THAWA · Post by **THAWA** » Sat Apr 10, 2004 5:56 pm

I could just see someone with spline drives or an STi knob on their turbo

vrg3 · Post by **vrg3** » Sat Apr 10, 2004 6:33 pm

On the turbocharger? Those are banjo bolts...

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External engine oil cooler

External engine oil cooler