Who runs a oil cooler anyway?
My oil runs too cold most of the time as it is.

Cooper S owners...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Bloody cold in Goulburn .

Maybe now but not in Summer.

According to published figures (Scientific Publications Workshop Manual Series No64 Morris Austin Mini, Pg 224), standard mini oil capacities are:

Engine/transmission including filter 4.83 litres
With oil cooler 5.25 litres

I compared this on the weekend with an old oil cooler I had, and the above appears to be a pretty accurate measure. This works out at 8% of your old oil not being changed if you don’t empty the oil cooler contents each time you do an oil change.

If you happen to do low miles/kms between oil changes and your engine is in good condition, then I don’t really see any concerns. However if your oil gets pretty dirty between changes then it might be worth considering cleaning out the oil filter oil as well. Just think, after doing an oil change how would you feel about pouring 8% of your old black dirty oil back into the mix...?

My car is a '70 Cooper S which came out with an oil cooler as factory standard, so I’m going to keep running one and keep my car original. The engine has been recently fully rebuilt, and has a new oil cooler fitted. I’ve fitted some rare earth magnets to the oil filter and sump plug to assist with picking up any fine grit in the oil. Also, I don’t tend to do short shopping trips in my car, and so the engine always gets to full operating temperature for a decent amount of time in a generally warm climate (Sydney).

I reckon if I lived in a genuinely cold climate – England, or say Goulburn – then then I might reconsider running an oil cooler. If your car didn't have one standard, then I really don't see too much benefit in running one unless your car was seriously highly tuned, or doing a lot of trackwork.

In the meantime I'll just make sure I do regular oil changes (Valvoline XLD Classic), and probably clean out the oil cooler oil every 2nd/3rd time.

Any further thoughts?

Why would you not replace the oil filter every change?

I think he meant cooler !

An interesting analysis and obviously worth considering to maximise the likelihood of preserving the internals of our very prized possession.

Have you thought about how you will actually do it? Will you remove the oil cooler completely each time and invert it, or disconnect the output hose and run the engine briefly until the new oil comes out, or disconnect both hoses and manually pump some new oil through using a suitable 'service tool' so as to expel the old oil, or something else?

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ex-NSW Police 1970 MK II Cooper S
VMCI #43

It's only oil. It is not like a filter change where failure to change it in time risks blockage due to contamination.

IMO not draining the cooler is like when I'm only changing the filter at every 2nd oil change. The amount of oil left behind would be around the same. it's no big deal, it's how I roll (mind you the oil gets changed every 1500 miles). Oil still looks clean on the dipstick, filter changed or not.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Oops sorry, that should have read "oil cooler oil" - now fixed.

Oil filters are are cheap and warrant changing every oil change.

As you would any oil change, make sure that the engine oil is warmed but not too hot. Then remove grill (on roundnose), couple of screws holding oil cooler onto panel, and then the oil cooler hoses. Decide which end of the oil cooler hoses you disconnect so that you minimise oil still in the oil cooler hoses running/dripping from down the front area.

Once the oil cooler is removed, just tipping out the old oil (still warm) should remove nearly all of it. If you think that the oil cooler contains some sludge build-up or grit, you could flush the oil cooler with kerosene. Though as mentioned, a new oil cooler is not that expensive if it's too far gone.

When it was daily driving mine it meant short trips to work in winter.
It just put a piece of plastic in front of the oil cooler to block air flow, sort of like a manual oil thermostat.
It worked well. I got the idea from a Kenworth truck and its radiator baffle.

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Too many cars, and too little time.

Bit of real estate agent sign coreflute (painted black) works for me. Stuck in front of the cooler. In the past have also used cardboard, but they dont like the rain.

a covered 13 row oil cooler allows the oil to get about 20 degrees hotter than when uncovered

For winter I use a piece of clear Perspex cut to fit. Drilled some small holes top and bottom through the Perspex to line up with the 2 vertical brackets on the back of the grill and cable tied around grill brackets and through holes in the Perspex. It completely blocks off airflow onto the oil cooler and helps to keep water off the distributor cap and leads. Works a treat and doesn't matter if it gets wet like cardboard.

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1963 Morris 850