Wet Sumping Poll

The dangers of wet sumping or lack of continues to be debated. So in the interest of science:

  • I never knew about it until recently.

    Votes: 3 2.4%

  • I never worried about it, and never had a problem.

    Votes: 55 44.0%

  • I worried about it but never had a problem, installed a new seal on my lapped (or new) oil pump .

    Votes: 11 8.8%

  • I worried about it , never had a problem, installed a shut off or check valve.

    Votes: 5 4.0%

  • I worried about it, installed a modified breather system, no valve.

    Votes: 25 20.0%

  • I had a slight problem, like hard starting, installed a shut off or check valve.

    Votes: 19 15.2%

  • I had a problem, like a failed main seal, installed a shut off or check valve.

    Votes: 4 3.2%

  • I will always build a Norton with a shut off or check valve.

    Votes: 3 2.4%
  • Total voters
    125
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Fast Eddie said:
If they stick open, can they also stick closed? Or at least partially closed?
Click to expand...

Didn't ever happen to mine. I think start up pressure forces the plunger back and then it rocks in the bore. The steel plunger had sharp edges and when it rocked it tended to dig a small mark in the alloy and then it stayed there. The spring was pretty lighweight, thin wire guage with plenty of turns. Though I am sure someone will tell you they have had one working well for 40 years I doubt anyone has had one work for more than a handful of start ups!
 
Fast Eddie said:
Same here. Mine has to be left a long time before the oil level drops enough to expose the filter screen though.

With the Comnoz breather the sump is emptied to normal operational level in seconds upon start up.

In my book, this just ain’t a problem.

I’ve nothing fancy or controversial in my oil feed. I just fitted a new ANIL pump when I built the motor. Seems to me that if the wet sumping ever does become a problem, it’ll just be an indication that a new (or refurbished) pump is in order.
Click to expand...

Only problem I have had is that when the sump is full of oil I did get a leak from the read valve gasket! Popped the fairing lower off and wiped it occasionally between races to keep it dry then when run it would be good for several hours! I need a new gasket! And to trim a millimetre off of the two screws that touch the crankcase when the gasket is crushed!
 
Dommie Nator said:
What about a "I just drain it out and put it back in the tank" option?
Click to expand...

And what about, just after a ride, aspirate in the tank half the oil with a syringe? Then empty the syringe in a can, and put the can on the seat or under the bike to remember for next ride.

Like this you take advantage of half wet sumping for cam splashing at each start. Without the need of draining each time...
 
The first time I owned my Commando I rode it for 9 or 10 years, 1974 - 83. I never heard of this phenomenon, nothing ever happened (that wasn´t my own fault) it just worked. Didn´t hear about the wet-sumping until I bought the bike back 3 years ago and joined this site.
Tommy
 
LOL...yeah, funny that now we have all sorts of "problems" with these bikes that must be corrected. But back when we actually rode these bikes and put serious mileage on them we didn't know all the problems existed. I think that's because...well, because they don't. ;)
 
MexicoMike said:
LOL...yeah, funny that now we have all sorts of "problems" with these bikes that must be corrected. But back when we actually rode these bikes and put serious mileage on them we didn't know all the problems existed. I think that's because...well, because they don't. ;)
Click to expand...


Sometimes the “fix” becomes the “problem”. Not long ago some were touting the virtues of a spring loaded valve in the intake line of the pump. How many Commando engine were destroyed by that “fix”?
 
fiatfan said:
The first time I owned my Commando I rode it for 9 or 10 years, 1974 - 83. I never heard of this phenomenon, nothing ever happened (that wasn´t my own fault) it just worked. Didn´t hear about the wet-sumping until I bought the bike back 3 years ago and joined this site.
Tommy
Click to expand...

You never heard of it because you used the bike every day, or several times a week. Wet sumpings occurs when the bike is not used frequently.
 
Actually, not quite true but almost.
My 1973 Mk2a engine in Slimline frame used to wetsump quite badly since I bought it a few years ago.
I used to drain it before starting the engine, until I bought a brand new AN oil pump last year.
Problem solved.
I think that 45 years is probably quite a reasonable lifespan for a Norton gear oil pump and its 160€ pricetag a lot cheaper than having to rebuild the engine after fitting a tap (whatever the system) on the feed.
My 2c.
 
NKN said:
You never heard of it because you used the bike every day, or several times a week. Wet sumpings occurs when the bike is not used frequently.
Click to expand...

Exactly.

Every time the question comes up some one will tell you to ride it more often.
I think we all know that, but it isn't going to happen.

It's a multiple bike/old guy problem. And if the multiple bikes are mostly old dry sump Brit bikes, after a month or so the sumps are going to be getting full. After two months, very full.
Mostly it's an annoyance more than a problem.
I did have a tiny pieces of rock get in the rocker feed line on one bike.
That partially blocked the oil flow.
Guess I didn't clean around the sump plug well enough before draining.
Now I strain the oil before putting it back in.

The one bike with the valve is the favourite, I don't have to piss around with it before riding or remember to start it up a couple of times thru the winter just to pump the oil back.
It also doesn't leak oil on the floor and on itself, something my wetsumpers all do when sumps are very full.

Glen
 
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JimC said:
Sometimes the “fix” becomes the “problem”. Not long ago some were touting the virtues of a spring loaded valve in the intake line of the pump. How many Commando engine were destroyed by that “fix”?
Click to expand...

Yeah well we heard that same mantra many times before :confused: But what are the actual facts? Maybe we should start another poll ‘What particular type/brand AWSV device did destroy your engine?’ So we will know which type/brand proved wrong and should be avoided. Please don’t give me the ‘all AWSV devices are no good’ answer because for example I am using an AWSV device (in combination with an oil pressure gauge) for many years and countless miles with great satisfaction.
 
nortonspeed said:
Yeah well we heard that same mantra many times before :confused: But what are the actual facts? Maybe we should start another poll ‘What particular type/brand AWSV device did destroy your engine?’ So we will know which type/brand proved wrong and should be avoided. Please don’t give me the ‘all AWSV devices are no good’ answer because for example I am using an AWSV device (in combination with an oil pressure gauge) for many years and countless miles with great satisfaction.
Click to expand...


If it’s between the oil tank and the pump it’s no good. Common sense dictates that.
 
I have either ignored the oil in the sump and started it anyway, or drained the sump and reintroduced the oil into the tank. All this worked fine. Recently I bought a Pera vacuum oil change device and drained the tank that way (it does need to be warm). It was dead easy and if you, like many others, have gaps in your Commando riding exploits then this does the trick with minimum chance of spillage and some encouragement to oil the chain and generally wipe stuff down while you wait for the magic to occur.
 
'Just came across this thread (again), and thought I'd add some recent insight: stock '74 Interstate that wet-sumps after a month of non-usage. Due to extended family priorities (don't ask), the old girl has sat since last Spring. In other words, longer than twelve months. The mates were going for a ride last Saturday, and I was finally in a position to attend! A quick glance in the oil tank showed the level to be such that the inlet filter screen was exposed, but no oil on the floor (!), telling me that is was all in the sump. I thought "what the hell", set the cap back on the tank, turned everything on, and she fired on the first kick. In the couple of seconds it took me to swing off and peer into the tank, there was a solid flow of oil from the return line, and the inlet filter was now well below the oil level. Since my biggest fear is the cam getting oil, I have to assume that the oil in the sump had thoroughly covered everything in sight the instant she lit. Went on a very strenuous 100 mile ride, and she's no worse for the wear.
 
With my little science project heres some wet sump data
1975 MK3 fresh engine, lapped pump,MK3 antisump valve functional, not run 1 day ,300cc
1974 850, 2800 miles never rebuilt, pump lapped, not run 90 days , 1700cc
same 1974 , not run 2 days , 450cc
1973 850 ,32000 miles, unknown engine history, not run 9 days , 1000cc
 
Dellis said:
That gets my vote too.

Dave
Click to expand...
Used to drain the sump before starting, but I’m concerned about wearing out the threads in the crankcase. ‘72 and ‘73 750 crankcases have the breather at the bottom of the drive side. As mentioned above any oil in the sump clears out in about 30 seconds up the breather.
 
illf8ed said:
Used to drain the sump before starting, but I’m concerned about wearing out the threads in the crankcase. ‘72 and ‘73 750 crankcases have the breather at the bottom of the drive side. As mentioned above any oil in the sump clears out in about 30 seconds up the breather.
Click to expand...

If you have the big brass drain plug, there a guy on ebay selling them that have a smaller plug in the middle.
 
or a manual valve with electrical interlock, so no start without turning it on.. now available from ebay.co.uk
 
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