I think one of the dangers of wet-sumping is the reducion in volume inside the crankcase. So when you start the bike, there is a potential to "pump out" a crank case seal, owing to this reduced volume.
However, having said that, all my British bikes have had a wet-sump problem to some degree. And I've had no problems with "blown" seals in some thirty years of owning them.
Suppose that is exactly what happened when I used that Mobil1 oil...ending up with 2 quarts of oil in the primary chaincase....seal was a bummer to get out...but I got it changed and switched back to Castrol and the problem hasn't reappeared....but point taken about blowing seals...in principle...any seal in the system "Could" blow....all the way up to the rocker arm covers and at the bottom of the barrels, the whole area is open and free to the sump area and the pressure must indeed be a bit strong for all the seals, but I have never had any really nasty side effects from the exrta oil in the sump and even rebuilding the oil pump didn't stop the oil from returning into the sump...so....life goes on and I just don't worry so much about it....
But...I will admit that I have gotten "Winded" every time I have to start the bugger in the winter...no fun at all, and not even always successfull, if I'm honest.....maybe in my next life I will weigh more and can kick it over better...or just get it fixed....HUmmmm...thats an idea!
Best and safe riding! piperboy
Joined: 21 May 2004 Posts: 270 Location: Australia's Far tropical nth
Posted: Tue Feb 15, 2005 11:10 pm Post subject:
Piper boy
I have niether experienced it or know of such an ocurrence but Ibelieve the first thing that may well happen is that the seal between the crankcase and the primary drive can blow and of course the engine oil would flow into teh primary drive.
I am / have been always one for starting up and idling up to bring the oil back to the standard levels. Additionally , warming up the oil before delivering any "styck" to the engine / throttle.
My Trident was the easiest to repair the wet sumping.. but required the engine to be removed.. ALthough I did explain my method on www.triplesonline.com and one of the blokes in the USA emailed me thanking me personally for the idea.. and he did not remove the engine..and achieved the same result..
But again this is academic as we are discussing Commandos here !
Don't know much about the triples...had a workmate in 79 or so that used to have a Trident...but other than that...no personal experience with one.
The story with blowing the seal into the primary case is more than likely the main problem you would get from the oil being too full in the sump, as you say, but other than that...don't know...any other ideas, or should we leave this as the main problem.....and one we can live with?
Think so...unless one of you has another earthshaking reason to do something about it, I will leave it as is...but then there is a simple question...what, other than putting in one of these questionable valve things, can one do to stop this oil getting into the sump? Does this spell a new oil pump, or is there another solution or thing that should be fixed...or did these things do the wet sumping thing, back when they were new and the folks at Norton just didn't worry about it either?
Can't remember, just seems the problem was always there...sort of like a cold....it's there, but you don't think about it unless you have to sneeze.....
Best and greetings to the world down under.....
Joined: 16 Feb 2005 Posts: 16 Location: Portland Oregon USA
Posted: Wed Feb 16, 2005 11:06 am Post subject:
piperboy states "...in principle...any seal in the system "Could" blow....all the way up to the rocker arm covers"
PO installed a vent fitting on one of the rocker covers on my 74. Looks like a grease zirk but is open to the atmosphere. I didn't know what it was for and have had an expert opinion that "it was done in the old days to collect overflowed oil but was unnecessary". According to what piperboy is saying, could this have been (or is) a solution to pressure build-up in the oil system due to the sumped oil? IOW does anyone think that this might be the solution that keeps seals from blowing?
Gene
Think the valve on the rocker cover is an interesting thing, but it wouln't help releave much pressure, it isn't near the size of the breather tube, and if it was open to the outside air,,,woundn't it whistle? Save on having to install a radio in your helmet, no doubt, and I think I have seen this on some engines, but it never could have have much effect of releaving pressure...unless someone wants to point out my miscalcuation...Peace!
Joined: 21 May 2004 Posts: 270 Location: Australia's Far tropical nth
Posted: Fri Feb 18, 2005 2:11 am Post subject:
Hi Blokes ..
Since restoring my Commando back in the early half of the 1990s, my bike has always built up a oil misting on the crankcases below the front isolastic mount. This would be quite severe each time I did a reasonable ride.
Recently I took a PCV from an Australian GM (H) six cylinder engine and fitted it it as close to the oil tank as I could get it.. (After extensive inquiries and research..including the concept that any weak seal, gasket or joint is going to leak oil due to this same pressure.)
My theory being that with the crankshaft and associated hardware executes a massive pump with pistons, the pressure build must be severe.
I fitted this valve working on the research and the thought that if I put the PCV in it will allow discharge of crankcase pressure gases, but NOT allow the rising pistons to suck in additional air which then would be othewise compressed on the down stroke.
It works,....
My cases are now dramatically cleaner and require a "wash" only once in a while!
I would suggest that any open 'breather" or such fitted to an engine is another attempt to alleviate the same pressure.. but I for one would NOT be fitting and leaving an open tube protruding from my bike engine or any other engine. (It is reminescent of some of the older 1950/ 60s vehicle engines which hung a breather pipe down the side ~ what a thought!)
(Piper boy .. the weather down under is our "wet season" as we live in the tropical mountain regions of far northern Australia ~ high humidity and high temps.. high 20s. to low 30s.. too hot and humid at times to ride.. no dramas kicking over an engine here . as opposed to German winter/s! )
I fitted this valve working on the research and the thought that if I put the PCV in it will allow discharge of crankcase pressure gases, but NOT allow the rising pistons to suck in additional air which then would be othewise compressed on the down stroke.
(Piper boy .. the weather down under is our "wet season" as we live in the tropical mountain regions of far northern Australia ~ high humidity and high temps.. high 20s. to low 30s.. too hot and humid at times to ride.. no dramas kicking over an engine here . as opposed to German winter/s! )
Thanks for the weather report....snow and such here, and 07:00 the street has to be shoveled, even on Sunday...not plows here in our street...you do it yourself. Very good explanation of the way this PCV works, by the way...even got through MY think head.....Piperboy
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At the end of 1967 the Norton Commando was announced.
The Norton Commando was greeted with a certain amount of scepticism because on first sight the commando appeared to comprise of the old Norton Dominator twin cylinder engine mounted at an inclined angle in a set of new cylinder parts.
It was not realized that the new Norton Commando Isolastic method of engine suspension damped out all engine vibration and produced a machine which had uncanny smoothness for a vertical twin. In due course the critics were silenced and the Norton Commando had the distinction of being regarded as the first of todays so called superbikes. There can be little doubt that the original design concept of the Norton Commando has proved correct, since comparatively few modifications of any real consequence have been made since production commenced during 1968.
Now nearly 40 years later Norton Commando riders like us are a breed of our own, and as far as we are concerned its still more fun to go for a blat on the old Norton Commando, and fast. As a Norton Commando owner and enthusiast, my goal here is to promote and give credit to those who keep the Norton name going.
It is more deserving to give credit to the Commando itself, for after all these years it continues to be respected. The original Commando designers like John Favill are those who deserve the credit for developing this incredible motorcycle.
The Norton Commando Roadster and Interstate of the late seventies, never died. Although the Norton Villiers factory dispersed the tradition lived on. Today Kenny Dreer in the USA is developing the new 952 CC Norton. What a great looking bike this is, and its engineering is still based on the original layout. It will be interesting to see how the new 952CC Norton does in todays tough motorcycle market. One thing is for sure, I would own one if I could afford it.
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