Relationship between oil flowing between sump and primary chain case
Normally, oil simply does not flow between sump and primary either way.
Also normally, 120 degree triple, there is little air movement between the crankcase and the primary chaincase (and the air filter or atmosphere); generally only expansion as the engine heats up.
What usually changes that is a broken piston ring and/or badly worn bores/rings allowing combustion pressure into the crankcase.
Much being vented from the crankcase into the primary, much oil droplets condensing in the primary, raising the oil level there, the engine designers still did not want oil in the main bearing itself sapping the reduced power still being generated despite broken piston rings, badly worn bores/rings, etc. In "Main Bearing pdf", note the slots in the crankcase around the main bearing housing; however, not so clear there is the slot below the main bearing housing, shown better in:-
... the highest the primary oil level can reach, before overflowing into the crankcase, is that slot below the main bearing housing.
"Chaincase Lubrication"
seems to suggest that oil level is eventually maintained by the datum of the outer race of this main bearing.
I can see the reason for that interpretation of the workshop manual, but it is not correct.
if I have 3 ltrs of oil in the sump, (after standing), is it not reasonable to believe that the level of oil in my now "flooded" sump will be the same as the now overfilled oil in the chain case?
Correct.
if this be the case, in order to re-establish the correct oil balance can I not simply drain a quantity of oil from the chain case, (which is easily accessible), transfer to the oil tank, in order to ensure I have oil feed to the oil pump, start the engine and let the scavenge pump create again the levels of normality?
The operative words are "a quantity". You can only drain from the crankcase though the primary until the level in the crankcase reaches the bottom of the slot below the main bearing (you can increase this a little by putting the bike on the sidestand).
Once the oil stops draining, is that "quantity" sufficient to feed the pump until scavenged oil can replenish the tank? Bear in mind:-
. if you get it wrong, the fix is very expensive;
. the person who sized the oil cooler for BSA/Triumph is still around and posts on a couple of other internet forums; he has posted the triple pump shifts about six or seven pints a minute ...
the problem
the anti drain valve
Most likely - commonly the valve seat in the crankcase was cut poorly and/or the anti-drain valve housing was drilled slightly incorrectly, reducing the seat area for the ball. An American who posts on a couple of the triple-specialist internet forums makes a seat cutting tool that screws in place of the anti-drain valve parts; not sure if the reduced seat problem is always fixable.
However, anti-drain valve seat fixed as good as possible, do not discount the the possibility of a worn or badly-assembled pump - the latter leading to the former in 9,500 miles is not impossible.
anti drain valve
don't physically see this on my T160 - is the manual showing a previous version of the T160 - T150?
All triple engines have it, all have the same engine lubrication system.
This drawing:-
... shows the drive side of the crankcase and sump plate; however, what it does not show is the frame tube between these parts, the hex of the anti-drain valve and the viewer ... Engine in the frame, you have to get your head under the engine almost to the front of the sump plate, then look up and back between the sump plate and the frame tube;
the anti-drain valve is actually quite a small hex, on the outside of the part of the crankcase enclosing the oil pump.
it is not identified on the oil flow schematic (the one appearing to be hand drawn) and neither on the drawing 3D schematic I posted as attachments previously.
It appears in the T160 workshop manual "Engine lubrication diagram" ("Fig. A2", page A4); however, you need the actual paper manual to see it more clearly than the online manual, where it is not reproduced clearly.
As I posted for you earlier, the anti-drain valve is depicted just to left of the oil pressure switch depiction on that diagram. If you follow the oil route from the bottom of the oil tank into and then out of the oil pump, the diagram then shows the oil apparently taking two "V"-shaped routes between the oil pump and the oil filter. The anti-drain valve is on the point of the 'lower' "V"; however, as that is a 2D depiction of a 3D system, in 3D the anti-drain valve is not actually next to the oil pressure switch - on the rear of the crankcase oil filter cavity - the anti-drain valve is on the
front of the crankcase oil
pump cavity; it is only the viewing angle of the "Engine lubrication diagram" that
apparently places oil pressure switch and anti-drain valve side by side.
I read that some 7000 T160's were produced,
IIrc, 7105 - XK00101 to CN07203 plus 00052 and AN07500.
been thinking about it all - and wondering how much "aggravation" at my age I actually need in my life.....
they receive positive appraisals from classic bike "aficionados" - and no where have I read "Beware!!! don't leave them standing" - they wet sump and it is messy and a bal* ach* to put the oil back where it should be.... "
Depends what you call an "aficionado", and how much space and/or time they have. Less of either, even an actual enthusiast is more likely to write/talk about the good bits than the bad bits. While the actual task of draining oil from the crankcase and putting it in the tank might be "messy and a bal* ach*", so are several others I can think of - e.g. cleaning the carbs because of ethanol in fuel. However, because these tasks are "messy and a bal* ach*", actual enthusiasts either fix each problem or find ways around it.
Any T160 is around 45 years old and has been used for anywhere between 37 and that 45 years; whether that use was much high mileage and a bike's worn out, or much sitting around in damp garages, any bike has aged, they never worked like a modern bike and they never will.
But T160's are not particularly unusual, any of their Japanese, Italian, German or American contemporaries also have foibles that have to be fixed or worked around. Having done that, a T160 is rewarding like no other British bike.
So how many owners are aware of it and moreover, take them out every sunny day (and have been doing for many years) not realizing that upon initial start up there is actually no oil in the oil tanks (as it is all in the sump)...?
How many adults would spend several thousand pounds/euros/dollars/etc. on any 40 year old vehicle without doing any pre- or post-purchase research? The few that would are simply going to waste their money wrecking their purchase? You are doing post-purchase research.
From an empty oil tank to sufficient oil entering the oil pump to create oil pressure - how long does this actually take
When you are watching the oil tank return for oil returning ... a
very long time ... it is one of the reasons "Waking The Sleeping Beast" recommends putting oil in the crankcase of a rebuilt engine before attempting to start it ...
during this period on low idle, is any damage really done?
I do not know, never tried it. Many years ago, I paid to fix a T160 engine that suffered a collapsed oil hose; that puts me off experimenting with the lubrication system.
From memory, the British police used these bikes for some time and I just cannot see the police transferring quantities of oil around a motorbike prior to starting it and taking it out.
a) The police do not leave expensive motorcycles standing around for a week between uses; b) if they did and all the oil transferred from the the tank to the crankcase, they would consider that a fault, remedies would be tried, eventually the engine would be stripped by a mechanic, anti-drain valve and oil pump checked as a matter of course, any faults found fixed.
Afaik, British police never tried the T160; perhaps you have seen the "Cardinal" version sent mainly to Saudi Arabia? I believe Birmingham police trialled Rocket 3 soon after they were launched (Birmingham normally bought BSA) but found even them too heavy.
not clever enough to "quote", " copy" and "reply" as per the structure of your response Rudie, (how do you do that...?),
When you click on "Reply" under a post, the forum software copies the text of that post into the Message Box under "Reply to thread" at the bottom of the page. While this implementation of the software hides it from you, the text has what are called "HTML tags" at the beginning and end of the text; when the text is displayed to you, the software interprets those particular "tags" to draw a box around the text and put the poster's name above the text.
If you want to 'break into' the quoted text - say it contains two or more questions or statements to which you wish to respond separately - simply position the cursor where you want to break in and tap 'Enter'; the forum software will split the quoted text into two boxes with a blank line in between, where you can type your response.
E.g. to pick out the quote above, first I positioned the cursor to the left of "not" and tapped 'Enter', then I positioned the cursor to the right of "?)," and tapped 'Enter' again; your post now split into three boxes, I simply Cut the box above and Pasted it at the end of my post. If my previous statement looks simple, be aware it takes a little practice to find the correct start and end cursor positions to Cut (or Copy) both the displayed text
and its hidden HTML tags - so it displays correctly after Paste - the underlying software is not intuitive to use;
if you did not know it before, you will make much use of Undo (Ctrl+Z) ...