Electric scavenge pump

Even better, an auxiliary elecrtic pump and heater to clear the sump, pressurise the crank,lube the cam etc and prewarm the oil before starting.Its all do-able.

It's technology used on locomotive diesel engines not to mention Merlin engines. Makes sense to have oil pressure up and oil circulating before starting an engine. But even just sorting the bogey of a sump full of oil is worth a look at. Will a windscreen washer pump cope with SAE 50 when the temperature is lurking around freezing? Yes, I know I shouldn't be using SAE 50 in winter but sometimes it happens. Would love to see it done. Gordon.

Merlins weren't originally fitted with electric auxilliary oil pumps - it's a modern addition. The idea is that because they stand for weeks or months between starts, you want to reduce wear by getting oil circulating before it fires up. So the important bit is the feed side to raise pressure rather than the scavenge side clearing the sump. Inverted engines like the Gipsy Major or radials like the Alvis Leodines do wet sump, filling the underside of the pistons and sometimes the cylinder heads with oil - so you have to take the plugs out to drain the heads. Failure to do so produces a hydraulic lock, bending the con-rod or pushing the head off. A Piston Provost I have flown crashed fatally last year due to con-rod failure caused by starting the engine without draining the cylinder heads. Makes our wet sumping problems seem trivial. Gordon.

I saw this idea in an old classic bike, it was on a Matchless twin and used your exact plan, a wiper wash motor connected to the sump and the oil tank and used to clear the sump before starting.

Bearing in mind that the Commando oil can get hot enough to melt plastic oil lines if the incorrect material is used, I'd be very wary of introducing unknown components into the lubrication system. Aren't these usually vane type pumps ? They are likely to include some plastic parts which may or may not be resistant to solvents and oils and there is also the risk that the pump could become an unintended engine breather which probably wouldn't do it any good at all.

I can imagine a Murray Walker type commentary as a Commando explodes in a cloud of smoke "Oh my goodness ! His windscreen washer pump has blown !"

I think that I prefer the risk of wearing out the drain plug threads.

The old adage is "Add lightness and simplicate". Adding extra components which can fail to the lubrication system may not be such a good move. I learned my lesson when an oil pipe came off the in-line oil filter which I had added some years earlier - and worse, it was on my wife's bike which I was riding when it seized... See also the thread about in-line filters and fuel lines and ethanol in petrol. Gordon.

Hi All it takes about 30 seconds to drain the oil tank after a run ,but don't forget to hang a tag on the bars with (NO OIL) ,easy and simple .If you have more than one bike use a seperate container with lables and put the same oil in the same bike .Steve

I have had very good luck with the anti wet sump devices sold by Mick Hemmings. They prevent oil from draining from the oil tank to the engine when the bike is not being used.