i would imagine drilling the shafts the same diameter as the line or as close to it as possible so a pressure drop isn't experienced would be proper? I know a ton of pressure isn't needed up there, but...

What do ya'll think?

No just drill them with an 1/8 inch drill bit. They are case hardened only So a #3 carbide center drill will break the skin, than a normal drill for the soft steel inside. Yes the thread is 5/16 -22 same as the gas tank bolts on BSA's. So the oil goes right through the first rocker shaft into the second (They meet in the casting) than through a drill way up to the exhaust side and so on. Why the factory did all this extra plumbing with fittings on a high pressure rocker system is hard to say. It sure makes no sense to leave it that way now.

I just can't resist posting this one. There was a Commando oil line with 4 banjos. Dunstall sold a cam with oil holes drilled through the lobes and fed from the left end of the cam. He supplied a rocker oil line with an extra hose running down to a fourth banjo that fed the left end of the cam.





Ken

norbsa48503 wrote:No just drill them with an 1/8 inch drill bit. They are case hardened only So a #3 carbide center drill will break the skin, than a normal drill for the soft steel inside...

They are not all the same .
Sometimes it will suffice to grind off the skin of the hardened , chamfered tip and the rest is easy drilling ,
But some are harder and are a pain to drill all the way trough .