Here we go again

[vibrac]

Fired up the Vincent Comet same petrol in the tank over winter (last of the Esso zero ethanol perhaps) you have to love the lithium battery still charged after 5 months in an unheated garage all that power in an old black Lucas battery shell one push of the starter button no valve lifter and away she went magic! good run round the lanes.
Only when I got back I remembered I had even forgotten to drain the sump :-0

 

[bmetcalf]

I had the impression that it was your habit to leave the crank in the "anti-sump" position.

 

[vibrac]

Thing is Bruce there is no way to tell now but its worked before and on pressing the button she certainly just went woof woof woof and fired up so I cant believe the case was full

 

[Cyborg]

I had the impression that it was your habit to leave the crank in the "anti-sump" position.

I tried experimenting with my Comet. Made a spigot that screwed into the drain plug. Drained the sump with the crank at BDC, then opened the valve that I installed on the feed line. Measured the amount coming out the spigot over a 48 hr period. Then rotated the engine to TDC and left it for another 48 hours. It sumped about 1/2 the amount of oil. Repeated the test to confirm things…. this time on TDC, it sumped more oil than on BDC. I was going to keep repeating the test to verify the flow at different pump rotor positions, but decided the whole thing was just a PITA and will just use the shutoff valve on the feed line.

 

[erik]

My Comet is not wet sumping at all.But!? What has the crank position to do with wet sumping? This is only on bikes with shells istead of rollers. In the shells there are sometimes holes which correspond with little jets in the conrods pissing oil on the inside of the pistons . If this little jet and the oil feeding hole in the crankpin is in line oil has nearly no resistance flowing in the sump. To my mind only the position of the oilpump can restrict the wet sumping on a Vincent,single or twin.Regards Erik

 

[vibrac]

lt could well be that the 'closed position' of the oil pump often (not always) coincides with TDC on compression stroke. By that I mean just on my bike by serendipity
Anyway the comment was just a by line on my post about my love affair with the Comet electric start and the li battery. I hope my twin bike I am building will have a starter as reliable.

 

[erik]

Does anybody knows how many crank revs per pumpstroke ?

 

[timetraveller]

15 with a single start worm.

 

[erik]

Thank you Norman! This means that it is nearly impossible to find the perfekt oilpump Position against wet Dumpingpreise!

 

[erik]

Wet sumping ( I don‘t know how to switch off the automatic word korrection ?)