ET: Engine (Twin) Oil change with anti sumping valve

[Kevin Emery]

Hello

I have a series C twin. I am gradually working through 'things to do'.

I have fitted an anti sumping valve. It works well. But, how do I drain the oil from the tank now?

Thank you in advance for your help with this.

Kevin

 

[GBewley]

I made a simple round plate slightly larger than the oil tank filler mouth, with a hole drilled in the middle to match one of my air blowoff guns on my compressor. Some thin rubber was bonded to the plate to allow it to seal against the top of the filler. Pull the cap off, remove the feed banjo at the engine and pressurize the tank and it is a quick job. The other option is to take a spare oil feed line fitting as fitted to the oil hose coming out of the oil feed at the back of the tank and put a length of hose on it. Replace the "running" hose with this and let it drain by gravity.

 

[vibrac]

Boy Im glad I dont fit these valves...

 

[GBewley]

Yeah, I haven't fit one in years, but I do tend to keep tools I’ve made around for the eventuality of customers bikes which have them.

 

[TouringGodet]

Boy Im glad I dont fit these valves...

Me too

 

[Kevin Emery]

Thank you for your replies.

So it's looks like this is a poor piece of design. It fixes one problem but creates another. This solution has not been properly thought through.

Are there any other solutions out there for draining the tank, after all, there must be many of these anti-sumping valves fitted with some creative solutions.

 

[ericg]

Never seen this type of valve but I have a ball and spring ASV on my Commando for about 30 years and 50 000 miles with no problems so far. An oil pressure gauge is fitted between speedo and tacho as a safety checking device.
Same on the Norvin twin, ASV from Conway's for 10 years and 25 000 miles, no problems neither. Checking device is a piece of clear pipe on the return line as Egli practice.
These are facts so an ASV will be fitted to the Comet as well when it's ready. I think the key is air tightness between valve and pump.
They were factory fitted on Velocette. Any Velocette owner here to let us know if there are recurrent problems with them?

 

[erik]

Another way to change oil with an anti sumping valve is to suck the oil out of the tank through the filling hole.If you take a not too thin hose you suck the oil by your mouth until it reaches your lips and then you put down the end of the tube very quickly .The result: the oil is flowing into your old oil pot by gravity! Erik

 

[Ian Savage]

I made a simple round plate slightly larger than the oil tank filler mouth, with a hole drilled in the middle to match one of my air blowoff guns on my compressor. Some thin rubber was bonded to the plate to allow it to seal against the top of the filler. Pull the cap off, remove the feed banjo at the engine and pressurize the tank and it is a quick job.

Glen
I like this solution but I think I have an old oil tank cap that I'll fit a tyre valve to. I made one like that to pressure test a fuel tank after repair.
If you do that fit the rear tank brace and only use a very few psi. You'll be surprised how much the tank swells under pressure!

 

[Martyn Goodwin]

Simple - remove that anti-sumping valve!