Wet Sumping Redux

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Well, actually, I think somebody has posted on blowing a primary seal from wet sumping and the guy who rebuilt his engine for nothing came from this board too.
 
Danno said:
bill said:
Danno said:
I have been told the Mk III has an anti-wet sumping valve built into the timing cover. There is a check valve between the pump and the rocker shaft oil supply that's not present on older models, but i can't see how it would do anything but stop the oil in the rocker line from draining back. Something's going on that keeps all but a little from draining out of the tank. More precision in later oil pumps?

danno
you need to do a little more research before you post on this. THE CHECK VALVE STOPS THE FEED TO THE CRANKSHAFT/ROCKER FEED PASSAGE!!!! with that said it is also known that that valve sticks and no longer functions as meant.

So the crank is lubed by way of the same outlet as the rockers? My research will consist of measuring how much oil there is in the sump after x amount of time since I just changed the oil.

danno
here is a timing cover so you can see how it works. the MK3 valve seals the oil pump outlet

Wet Sumping Redux
 
That passage doesn't feed the rockers. The rocker feed comes off the crankcase, remember?
Seems like I'm getting at you!! Not so but that gallery does feed the rockers, where the banjo attaches at the rear of the timing cover.
 
grandpaul said:
That passage doesn't feed the rockers. The rocker feed comes off the crankcase, remember?

Look, I just enlarged what was on the picture. :mrgreen:
 
bill said:
bill said:
Danno said:
danno
you need to do a little more research before you post on this. THE CHECK VALVE STOPS THE FEED TO THE CRANKSHAFT/ROCKER FEED PASSAGE!!!! with that said it is also known that that valve sticks and no longer functions as meant.


danno
here is a timing cover so you can see how it works. the MK3 valve seals the oil pump outlet

Wet Sumping Redux
Thanks. it's been a good while since I've had the cover off. I have an old cover I should have dug out and looked at.
 
I want to close this thread out by comparing the data sent to me by forum members.

I started this thread when I checked on the state of the sump of my stationary Mk3 and was surprised by 1 1/2 quarts of oil that streamed into and out of my 1 quart container. Since then, after topping off, I measured the sump flow over three days (results below). My mk 3 is a complete rebuild, but the oil pump WAS NOT refurbished as it looked good and passed the manual pump test (the bike has 24,000 original miles on it). I did refurb the check valve, which was, as many have stated, inoperable and stuck open. My measurement was made with the pistons at TDC.

Compiling the results:

Mexico Mike 1973 Commando refurbed pump no TDC 1.3 oz/day
PJL 1972 Commando 750 Combat no pump refurb at TDC 0.74 oz/day
Rick in Seattle 1975 Commando 850 Mk3 no pump refurb new check valve at TDC 0.96 oz/day

The manual reminds us to expect a "normal" sump oil volume of "a teacup or so" , say 8 oz? It appears from the remarkably consistent data above that this translates into 1-2 weeks of inactivity. Standing for a month, at least for the bikes above, would drain 1 quart (4 teacups?) into the sump. For myself, I plan to ignore wet sumping during the riding season as long as I fire up the Norton at least monthly. I'll drain the sump in the spring before that first delicious ride in the dry.
 
steven wardlaw said:
I've got one one cnw anti sump check valves and I don't really trust it . I wish I had a manual cutoff vave that also had a ground wire switch for the ignition so that you could not crank the bike with valve in shutoff position. As much as I don't trust the anti-sump valve I also don't trust myself to turn a manual valve on and off.
Sorry to keep it going Rick but this bike has a mechanical electric switch that looks interesting. It just needs to be located beside the ignition switch for convenience.

http://cgi.ebay.com/ebaymotors/Norton-D ... 951wt_1167
 
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