Yes, the solid upper bearing shell came to be after several of us concurred that the problems Jack (Hotater) was having with his 25,000 hour engine eating bearing shells resulted from failure to maintain an oil film. The channels in the upper shell were bleeding oil film away from the surface where it was most needed. So (I think it was) George Breckenridge, ordered some bearings with the solid upper shell, over the strident objections of the Indian supplier, and, oiling from the bottom via a hollow dipper, the problem went away. The upper oiling holes bored in the big end of the crank were also thought to funnel any grit/dirt that might make its way down the con rod into the bearing along with the oil. Another reason to use the hollow dipper.