Hi,
My name is Jake Powell and I'm from Nebraska. My Dad has built an entire 1947 Harley Davidson Knucklehead, it runs great with the exception that the rocker cover tins leak every time. He had new top and bottom tins when he started but I have heard that origionals had vent holes drilled in the top tins. I think the tins fill up with oil and the pump deadheads because he has also had the pressure relief valve get stuck and it seems to coincide with the leaks. He has had to use panhead aluminum engine cases but the ports all seem to line up. What we are wondering was if there is a way to ensure crankcase vacuum is applied to the pushrod covers which is necessary to suck the oil out of the lower tins and thus prevent leaks. Also how does the breather gear really build vacuum if the downward piston stroke pressure has nowhere to go?! Have you ever seen this before, I think it's a common problem but have no definitive answers???
