I suggest ya take a really good look at any of the C/CA/CB/CL/CP72/77 crank assy and you will find that the oil under pressure goes to the 2 center and right side bearing and the rods and left side bearing are lubed by a SPLASH technique used with many engines.
Of course the valves are oiled with pressure and that oil once it has passed through all the rockers and splashed on all those parts up there, cam chain included finds it's way to the bottom to enter the oil pump and go around again.
HONDA didn't pressure the oil to the starter sprocket cause the pressure would eventually supply more oil than the sprocket will ever need and that the case pressure is plenty at the point.
When ya blow a Clutch Rod seal ya will learn what case pressure can do for soaking the right side of the engine and floor.
I will check one of my CL72/77 crank assy and get back as to the depth of the hole from the balance weight end of the tapered rotor shaft. ..............lm
ricksd wrote:Good information, now I need to reconcile fact/observations from several experts, LM, Gman and Jensen, into a plan of action.
First, It's a little hard to believe that the same Honda engineers who choose to vent valve guides would rely on unpressurized oil finding it's way into a hole in the crankshaft and up to the starter sprocket bushing, so Jensens' observations of a disassembled crankshaft make sense- oil being forced into the sprocket bushing passage. But, LM and Gman have both found that if you blow into the hole under the sprocket in a CB crank there's a path for the air to escape through the crankshaft stub into the crankcase- it seems that most of any pressurized oil would run out that hole rather than up to the sprocket bushing, and Gman can't find any pressurized oil passages from the rod big end, so no clear picture in my mind yet. Wish I had a CB crankshaft I could cut a section through.
Honestly, I'm not trying to make simple things difficult, but would like to understand how this works, and I expect Superchicken would like to know more before he assembles his engine.
I did try blowing and probing the sprocket oiling hole in my CA crankshaft, but didn't come up with any useful info- I couldn't get any backflow of air from the sprocket bushing hole, but my CA crank is a rusted mess, and passages could be blocked.
Again, thanks for the help to this point, I understand more, but not confident that a hole under sprocket and an axial hole through the crankshaft stub is the complete picture- if that's all there is to it, a rotor bolt could be drilled to act a a drill bushing/guide, and the hole through the stub shouldn't be too difficult.
I'm going to study this more while I try to find a CB crankshaft
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