Using the trans oil cooler at the bottom of the radiator as an engine oil cooler

[GGR]

Hi all,

I'm fitting a manual trans to my '62 W111 Coupe currently equipped with a 3.5 engine and radiator. Currently, the 3.5 engine oil cooler is on the side, and takes fresh air from where the original air filter was taking it. This is not ideal, and doesn't look good. A proper job would require hacking the body around the radiator, and I would like to avoid this as much as possible.

Using the trans oil cooler in the radiator to cool engine oil, a bit like the M189 engine, would enable to avoid hacking anything and would make one less thing in the engine bay. How efficient would that be?

[Mike D]

Logic says it wont be as good as the sidemount but it would be better than nothing.

Oil being exposed to say, 75 degrees F airflow as opposed to coolant temps of 190 F. Of course then you consider the heat transference properties of a liquid versus the dissipation factor of the conducting fins in contact with a moving gas, then carry the 6...... You get the picture.

[ja17]

Hello,

Your radiator is not made to take the very high oil pressure produced when the engin is cold or at high rpms. I suspect that you would split the seams in the radiator almost instantly. The M189 engines had a water cooled oil cooler built into the engine block.

To handle the high pressures most of the early oil coolers were constructed of steel then brass welded together. Later units were aluminum and welded together.

Think about installing an oil temperature gauge on the car to see if you really do need an oil cooler at all. If you are not in a southern climate and you do not spend a lot of time at high rpms you may not need one at all.

[Tomguy]

FWIW I would not run my 4.5 without the oil cooler. I would not dream of running the higher-compression 3.5 without one, either.