Oil coolers

[Superheat]

I am now at the stage of fitting the radiator and oil coolers and need some advice.

The radiator has been re-cored but the transmission oil cooler fittings have been blanked off. There was a separate transmission cooler fitted with dimensions of 450x125x50mm (18x5x2" in rod ton fortnight units). This was adequate so I will be reusing it.

The engine has been changed to a 440 so a separate oil cooler could be useful as our ambient temperatures can be well in excess of 30degrees (and under minus 5 degrees too). Is there any rule of thumb for the oil cooler size? Would a similar size to the transmission cooler be adequate?

What is the pusher fan at the front of the radiator for. Is it primarily for when the car is stationary or is it to give additional cooling for the AC condenser? Do I need it?

I have two 12" Davies Craig fans fitted. They are Australian made so can blow a lot of hot air, but I understand that the Kiwi's blew cold air on them over the weekend. I will replace them with VW equivalents as suggested elsewhere on the forum.

Is there any risk of over cooling the engine and transmission fluids at very low temperatures? Probably little risk for the engine but not sure about the transmission.

Final question is has anybody else fitted the AC condenser, engine oil cooler and transmission oil cooler in front of the radiator? It will be fairly full so cooling may be compromised. I am thinking of the merits of an oil cooler behind the transmission which will have a (small) benefit in weight distribution and opening up the space in front of the radiator.

[Jorrocks]

They are Australian made so can blow a lot of hot air, but I understand that the Kiwi's blew cold air on them over the weekend.

Seriously though, I was also wondering about the viability of setting oil coolers for engine and transmission in front of the rad /condenser. I kind of thought that with the 450W Veedub fans it might be possible. Whether it can all be made to look 'factory' is another thing....

[Jorrocks]

Something like this:

DSC01066.jpg (46.14 KiB) Viewed 4842 times

[RAP72]

Som photos of the work Wallace did on RAP 72, engine and gearbox coolers. As always with Wallace all can be reverted to original. More photos after this one.

http://www.joc.org.uk/Interceptor_Mk_1/ ... 72.html#18" onclick="window.open(this.href);return false;

[Chris_R]

Oil performs a significant amount of the engine cooling and generally dissipates that head by radiation through the sump or by the oil cooler that is part of the radiator. Some performance sports cars had fins on the sump pans to improve heat dissipation. Having the oil cooler as part of the radiator ensures that the amount that oil cools during its passage through the radiator is not excessive.
Any external oil cooler that you fit should be thermostatically controlled so that you don't overcool the oil because yes, you can overcool it. Once the engine has warmed up, the oil temperature should be maintained at around 90c. If it is much cooler than that it becomes thicker and increases friction in the bearings potentially leading to increased bearing temperatures and increased wear and also less oil splash onto other areas. Much hotter than that and the oil is less able to support the bearing loads, also potentially leading to increased wear.

[Joerg]

The Photo is from my CV8 before the rebuild.

Today it has no oil cooler ( total unnecessary -ask Peter Ulric who races a CV8 in Australia ) I have a 7.7 quart Milodon oil pan and that's fine. Engine is a 439 stroked with about 550 HP. Oil is always at 75 to max 85 degree Celsius even on very hot days - And we have no speed limit on our Autobahn

Transmission should always be cooled in a row. Out of Tranny into extra cooler into radiator cooler back to tranny, otherwise over cooling is an issue on cold days.

[Superheat]

Thanks Joerg.

Have you bypassed the radiator oil cooler as well? This would make the high capacity sump the only oil cooler? I'm all for simplicity if it works.

[Joerg]

Today´s setup:

Öl2.JPG (80.26 KiB) Viewed 4775 times

Milodon pan and high volume oil pump, a big filter and solid tubes, that is all.
No cooler needed at any temperatur.

Joerg

PS: Car has 5 speed manual gearbox now, so no need to cool the gearbox.
I would go for a B&M deep pan for the A727 to cool the box a bit more. Overcooling is bad for an auto-box!!

Foto314.jpg (98.53 KiB) Viewed 4774 times

[Barrie]

Whilst appreciating that over-cooling may be bad for an auto transmission I have heard that cooling is essential to prolong life of the bands. So I wonder what is the right temperature?

[Joerg]

Did some research on that topic, all friction elements (bands) work between 40 to 100 degree Celsius and any "hard work" for the gearbox should be avoided at temperatures below 60 degree.

Joerg

[Jorrocks]

Joerg,

Can I ask which model of Milodon sump you use? You have no ground clearance issues in normal street use, speed humps etc.?

Also, are you saying that a deep transmission sump like the B&M (+2 quarts) will provide sufficient extra cooling to the gearbox without any auxiliary cooler being required?

Eric.

[Chris_R]

Eric, A reasonable question to ask is why are you so concerned about cooling? Are you intending to use your car for racing or just for everyday use? It is a misconception that cool is good. It isn't, especially with oils.

[Jorrocks]

Chris,
Just fast road use. I was thinking ahead really, as the motor is due to have a big hop-up to 512c.i. over the winter, I was assuming more displacement & compression = more heat, so more efficient cooling might have been needed.

[Chris_R]

Fast road use? From Buckinghamshire ? When on earth are you going to find empty enough roads especially with UK speed limits and all the speed cameras! Plus on our UK roads, you'll barely find more than 1/2 a mile of straight, if you're lucky, before you have to slow down for a bend or a truck or a caravan in tow!

[Jorrocks]

Oh alright, drearily slow road use then! I forgot for a moment that I was in the UK

If I assume that the mounting of additional oil coolers, thermostats etc. is not going to be of benefit (And a lot of hassle!), would you think the extra oil capacity was worthwhile?