Big ends and the 3 start oil pump.......help!!

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Dec 3, 2018
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Im rebuilding the above and have a question I need answered and need your help!
Ive got the 3 start oil pump, scrolled rocker spindles, scrolled cam with plain bushes. My question is this with the low pressure system did the shell bearings have an oil hole?? If not i can swap the shells around and cover it .

Hope you can help
 
https://www.nortonownersclub.org/history/dominator

"From engine No. 116372 the con rods had a strategically placed hole drilled in order to squirt oil under pressure onto the cylinder bores. At the same time all models were fitted with a six-start worm drive on the oil pump, supposedly giving double delivery. Along with enlarged oilways, the rockers were now pressure fed from the delivery side of the pump."
 
https://www.nortonownersclub.org/history/dominator

"From engine No. 116372 the con rods had a strategically placed hole drilled in order to squirt oil under pressure onto the cylinder bores. At the same time all models were fitted with a six-start worm drive on the oil pump, supposedly giving double delivery. Along with enlarged oilways, the rockers were now pressure fed from the delivery side of the pump."
 
I mean the actual big end bearings oil hole, ive read that when using the 3 start pump there is no hole in the shells, this might not be right, that is my deliberation
 
I mean the actual big end bearings oil hole, ive read that when using the 3 start pump there is no hole in the shells,

Yes, as there obviously wouldn't have been any need for shells with holes until the rods were drilled.
 
https://www.nortonownersclub.org/history/dominator

"From engine No. 116372 the con rods had a strategically placed hole drilled in order to squirt oil under pressure onto the cylinder bores. At the same time all models were fitted with a six-start worm drive on the oil pump, supposedly giving double delivery. Along with enlarged oilways, the rockers were now pressure fed from the delivery side of the pump."

My Atlas is an enigma.

I have engine/frame No. 102688, dispatched to Berlina May, 1962. It appeared at my dealer in April, 1963 when I bought it new, and it was titled as a 1963.

This engine has from new, the 6 start oil pump, and the con rod squirt holes.

The NOC record has no indications that this bike was a special build, but having the oil system mods as noted above, would make it seem to be a special build. Further indication of a special build are the Monobloc carburetors which do not have model/configuration numbers stamped on the flanges.

Other possible indications of a special build are the fact that vibration, IMO, is no worse than any 650 Brit twin, the bike beats the snot out of any other Atlas I ever raced, and the engine is less tractable than the first Atlas I owned.

I hope this has not gotten off topic, but I think the occurrence of a 6 start oil pump and squirt holes much earlier than 1966 should be in the record.

Slick
 
I seem to remember Norton doing the oil hole drilled in the conrod on the Commandos – then they put out a factory circular stating that the holes in the big end shells should be reversed so that the holes do not line up with the conrods.
 
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