cyclinder cooling with external lines

i have a couple questions about the benifits of adding external oil lines to the cyclinder head, that ive seen many on GS motors. is the KZ oil system good enough left alone when putting in bigger cams, bigger pistons with higher compression?
doing the mod looks easy, with only drilling and tapping the cyclinder, and running lines from the oil plug. any thoughts

The 903/1015cc engine line has low oil pressure (under 5 PSI) most of the time. The external lines add oil to the cam area and are not really intended as cooling functions. I doubt these lines are necessary on a street bike.

check WG, what about lubrication?



i came across this picture

Not sure I understand what you are asking... The oil for your cams, at least on the 903/1015cc and J motor come up through oil galleys that the four outside engine studs sit in. These drool some oil into the cam area. There isn't all that much oil for hard acceleration so the go-fast crowd puts extra oil into the valve area via the extra external lines. I think they will also do some mods to the oil pump to put more oil out. You could ask some of the turbo guys who face oiling issues and need the oil pump to supply more volume and/or pressure. I doubt the area under the valve cover is particularly prone to heat related issues.

One of the reasons they use those external oil lines is that on using big-blocks, sometimes those outside studs are a tight fit in the bigblock. So they close off the oil passage up the studs and plump for the external oil lines. This also helps in oil leaking around the studs too. Big-blocks are notorious oil-leakers and this is one of the answers for that if you have that problem. Also, keeps oil cooler because it doesn't have to travel up block, though not sure how much it really helps in that sense. But mainly for a fresh supply of oil for the cams and help with leaks.

Good point, never thought about heavy duty studs being thicker... they are still 10mm where they screw into the block but the meat part will be more stout I guess. That means less oil. I ALWAYS have issues sealing the journals. I have re-annealed those stupid copper washers till I am blue in the face and STILL get dribbles. Wondering if anyone has ever used other types of washers to stop the leak around the outer stud oil journals...