Topic: oil squirt hole on the head ,are they drain back holes?

[mustangcar]

 ,noticed the two holes with the oil rings on the head near the rocker arm area, are they drainback holes?, some guys mention they might get clogged,i stuck some welding wire in them to see if they were clear,only went down in both holes about 7/8 of an inch ,where do they lead to?,can't see how the cam/rockers get oil,is it mostly by the cam chain flinging the oil? this on my buddys extra 750 engine that he has in his shop, i havn't taken mine apart yet ,thanks

[75750SS]

Are you referring to the holes in the picture (items 15 and 6).  Oil comes up and into the camshaft holder where it's sprayed onto the cam and rockers.  They can get plugged and if they do like mine did, you can fry the cam.

[mustangcar]

yes those are it,how does the oil get pumped up into them?,i flipped the head over and the oil holes don't go through, thanks

[mcpuffett]

oil travels up 2 corresponding studs from the crankcasings out of those 2 holes in to drillings in your cam holders or towers and then gets sprayed onto your camshaft,  i think thats right ? been a while since i was in side a 750 engine if i'm wrong someone will chime in , cheers Mick.

[mustangcar]

oh that would explain it ,cause all i saw was stud holes,next time i go to his shop iam going to try to blow some air into those tiny holes and see where they channel through, maybe most plug up from people using silicone as gasket material and that ends up in the oil passages,,,,thanks

[mcpuffett]

it only takes a little bit of dirt to get in there and your camshaft will be toast ,i've been there , cheers Mick.