While installing my cylinder barrel Iâve noticed that the oil passage leading to the back of the cylinder wall is significantly narrowed where it leaves the crank case at the barrel joint.
It is full size as it leaves the timing chest; roughly 1/8â diameter. But at the point where it enters the barrel it is reduced to roughly 1/32. It appears to me that the hole has been blanked then drilled out to 1/32 diameter. The passage returns to full diameter as it continues on through the back side of the barrel to the piston.
Soâ?is this correct ?
This narrow passage hole appears to be the same diameter as the hole in the spring loaded main crank oil feed jet. So perhaps this is by design ? Could this part of the Norton factory design to balance pressures between this passage and the main shaft oil feed jet ?
Orâ?has some previous owner decided to reduce the oil supply to the cylinder wall ? And by narrowing the passage he hoped to delivery more oil elsewhere?
Should I drill this out to match the passage in the barrel or leave it as it is ?
Grant MacNeill, Toronto
Attachments img_1563-jpghello Grant, not es2 but m…
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Previously Barry Carson. w…
Previously Barry Carson. wrote:
hello Grant, not es2 but my (56) 19s engine oil feed looks the same as in the photo i can insert a 3mm drill bit into the timing cover side feed hole and a 1mm drill bit into the feed hole you are referring to that feeds oil into the barrel from the crank case joint. see what others say.
Barry
Thanks Barry. That is encouraging. I am starting to think this is as it should be but hope to hear from anybody with an ES2 who can confirm
Grant
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Yes Grant, my '51 is the…
Yes Grant, my '51 is the same, small hole as per your picture. In fact, on my last re-build, I never punched the corresponding hole in the barrel base gasket effectively blocking it off tocurb excess oil burning.
Paul.
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hello Grant, not es2 but my (56) 19s engine oil feed looks the same as in the photo i can insert a 3mm drill bit into the timing cover side feed hole and a 1mm drill bit into the feed hole you are referring to that feeds oil into the barrel from the crank case joint. see what others say.
Barry
Attachments image1-jpg