Atlas rocker oil feed line

On those with rocker feed from the return line, the Norton instruction book says:
"Periodically, when the engine is ticking over, place a finger over the hole in the return pipe in the oil tank. This will send more oil to the rocker mechanism and serve to flush out the small holes that feed oil to the rocker ball ends."
I guess Norton did the change on later machines to have customers not always with oily fingers.

Mike40M said:

I guess Norton did the change on later machines to have customers not always with oily fingers.

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The petrol will clean it off the next morning.

On m

norton bob said:

Sometimes. I think the pattern of use made a difference. Bikes used for short distance possibly did not warm up fully and did not get enough oil , sludgy oil would block the small low pressure oilways.Looking into the exhaust valve areas ,it was often dry compared to the inlet side. Rockers could tighten on the spindles and make them turn and wear the supports. A little "tuning" of the bias at the tank union can fix this. Too little oil= wear and noise,too much oil =smoky exhaust,sooty plugs,burnt valves. A bit of a balancing act. But I have done it.

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On my 1964 G15 MK2 i have updated the system removing the line from oil tank return feed to timing chest and changing the scrolled rockers spindle with the flat commando one.
Bike doesnt smoke but has new valves and guides.

Mike40M said:

On those with rocker feed from the return line, the Norton instruction book says:
"Periodically, when the engine is ticking over, place a finger over the hole in the return pipe in the oil tank. This will send more oil to the rocker mechanism and serve to flush out the small holes that feed oil to the rocker ball ends."

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It's amazing and almost frightening to read this. Makes me wonder how the big twins could have such an appeal at the home market and abroad. Did owners really care about rocker ball end lubrication? Probably not. At the same time AMC made their twins with internal oilways from the bottom end to the rockers - the degree of detail is amazing. No bore to feed the rocker ball ends though - oil is channeled in a stream along top of the rockers. In either case, oil reaches the ball/pushrod cavity by gravity only.

-Knut

Whether from the scrolled shafts or indirect around the solid shafts with flats the oiling is adequate for the ball ends. What I am shocked by is the folks who fail to realize the large number of ruined early heads by using high pressure system out of a tiny hole only and the large number that then seized causing the shafts to rotate and destroy the head. The later flats very much increased the oil on the shaft where it needed is most when the rocker rotated heavily lubed into the stressed portion of the rocker and shaft interface. The rocker shafts with only the tiny hole seems to me, a big design screw up.
The scrolled shafts have constant low pressure to the ball ends due to the flat facing the ball end .

dynodave said:

Whether from the scrolled shafts or indirect around the solid shafts with flats the oiling is adequate for the ball ends. What I am shocked by is the folks who fail to realize the large number of ruined early heads by using high pressure system out of a tiny hole only and the large number that then seized causing the shafts to rotate and destroy the head. The later flats very much increased the oil on the shaft where it needed is most when the rocker rotated heavily lubed into the stressed portion of the rocker and shaft interface. The rocker shafts with only the tiny hole seems to me, a big design screw up.
The scrolled shafts have constant low pressure to the ball ends due to the flat facing the ball end .

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Can I ask if you only have a scrolled shaft, is there any reason why, if the shaft is not worn, you can't grind a flat there provided it's in the right place? After all, it's hardly a precision job is it?

Bernhard said:

Can I ask if you only have a scrolled shaft, is there any reason why, if the shaft is not worn, you can't grind a flat there provided it's in the right place? After all, it's hardly a precision job is it?

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Bernhard:
Certainly a reasonable craftsmanship task. A scrolled only shaft is AFAIK a recent phenomenon. It makes me wonder what is the rational for the change. Who and why was the change made? and was it valid reasoning.
There were several threads on NOC about flooded heads and in several forums evidence of sloppy fit of rockers shafts in the head. I initially suspect the reported screeching sound is the rocker chattering on the shaft or the shaft chattering in the head, either one due to hot thin oil under lubricating the shaft/rocker boundary.
Folks proposing that both the scrolled OR plain shaft systems, either one with or without the flats being reversed makes me think this is from total lack of knowledge, testing and direct observation.
https://www.accessnorton.com/NortonCommando/nht-early-hp-rocker-shafts-vs-hp-shaft-with-flats.30043/
152 views of the thread, yet no substantive expressed technical based views. I do have some opinions but that is all, nothing yet to back it up.

Yes I reread your previous post, the shafts turning in the head gave me a problem, as there is no meat on the head to fit a top hat tight brush.
I cannot see the harm in grinding a flat to aid the oil flow in the rockets, providing you have the six start worm oil pump with the rockets fed through a Commando oil pipe.