Here is my opinion as a General Electric Turbine Bearing Specialist! The full groove bearings provide oil to the
camshaft, lifters, and rocker arms all of the time. The factory race manuals state this. While a lower bearing
with no groove can take more load because of more surface area, More components get less oil which lubricates
and takes away heat. As the crankshaft turns, the oil supply intermittently spurts to the valve train with a half-
groove bearing, and heat can build up in the bearing and cause it to fail. In a Turbine, we put side pockets in
large turbine bearings so the oil wedge can work it's way under the shaft and lift the rotor. I have seen main bearings
with this little pocket in the lower solid bearing, but I think it's just useless. In a turbine, the oil in the bearing
gets used once to lubricate and take away heat. In our engines, it has to go on and lubricate the valve train.
Strictly my opinion. I'm not an engineer. The book says to use fully grooved bearings. That's my story, and I'm
sticking with it!
