- Joined
- Oct 19, 2005
- Messages
- 18,978
Ok, can someone interpret Mr Hudson's report, in regards how much oil is bypassed that the engine don't need and could be used for piston jets yet pump it all back out.
From Bob Davis in Oz about a decade ago.
On the oil pump, this may be of interest and is something I found while
bogging around in the pressure relief valve saga a few weeks ago. You may
have already read it. How accurate it is, I dunno......John Hudson is the
elderly guy who stars in the Brit NOC club videos on stripping and
rebuilding the Commando motor and g/box. Apparently he worked at the factory
forever till it's collapse. Is a lifetime member of the club, is or was the
president and for many Norton owners he has a seat up near the other elderly
white bearded gentleman in the sky.
Bob
I found some words penned by John
Hudson in a Classic Mechanics publication of his service notes for the 750.
(No. 8-9 Summer 1985) The article says and I quote "An oiling system
alteration on Commando engines, which may not be generally known, reduces
the rate of oil circulation in the tank. This is best explained by quoting
some approximate rates of flow. At 6,000 rpm the high speed large capacity
pump on these (Commando) engines delivers approx 26 gallons per hour. Of
this some 13 gallons per hour pass the big ends and maybe another two or
three pass the valve gear. This leaves some ten gallons per hour to pass the
pressure relief valve from where it goes into the timing cover and down into
the crankcase sump. Where the return pump has to send all 26gph back to the
oil tank.
By means of altered drillings in crankcase and timing cover on the
Commando engine, the oil discharged by the relief valve does not enter the
timing cover, but instead is diverted across the timing cover joint through
an additional loop on the gasket directly into the inlet side of the pump.
In this way some 10 gph less circulate in the tank.
When the timing cover is removed from one of these engines , oil
immediately emerges from the now open drillway direct from the oil tank. For
convenience this drillway in the crankcase is threaded 1/4 in Whit so it can
be temporarily plugged by screwing in one of the timing cover screws."
unquote.
From Bob Davis in Oz about a decade ago.
On the oil pump, this may be of interest and is something I found while
bogging around in the pressure relief valve saga a few weeks ago. You may
have already read it. How accurate it is, I dunno......John Hudson is the
elderly guy who stars in the Brit NOC club videos on stripping and
rebuilding the Commando motor and g/box. Apparently he worked at the factory
forever till it's collapse. Is a lifetime member of the club, is or was the
president and for many Norton owners he has a seat up near the other elderly
white bearded gentleman in the sky.
Bob
I found some words penned by John
Hudson in a Classic Mechanics publication of his service notes for the 750.
(No. 8-9 Summer 1985) The article says and I quote "An oiling system
alteration on Commando engines, which may not be generally known, reduces
the rate of oil circulation in the tank. This is best explained by quoting
some approximate rates of flow. At 6,000 rpm the high speed large capacity
pump on these (Commando) engines delivers approx 26 gallons per hour. Of
this some 13 gallons per hour pass the big ends and maybe another two or
three pass the valve gear. This leaves some ten gallons per hour to pass the
pressure relief valve from where it goes into the timing cover and down into
the crankcase sump. Where the return pump has to send all 26gph back to the
oil tank.
By means of altered drillings in crankcase and timing cover on the
Commando engine, the oil discharged by the relief valve does not enter the
timing cover, but instead is diverted across the timing cover joint through
an additional loop on the gasket directly into the inlet side of the pump.
In this way some 10 gph less circulate in the tank.
When the timing cover is removed from one of these engines , oil
immediately emerges from the now open drillway direct from the oil tank. For
convenience this drillway in the crankcase is threaded 1/4 in Whit so it can
be temporarily plugged by screwing in one of the timing cover screws."
unquote.
