F-Body Europe

Sustained high RPM in a straight line, or while handling the car, any gear, could do it to any stock engine in any brand box stock car at some point. The early LS1's grenaded from being handled hard at RPM. The oil sloshed away from the pickups in the early engines under hard cornering to the sides of the oil pans causing the pickup for the pump to suck air. The pans have since been modified with baffles and compartmented to keep oil from sloshing like that to one side or the other and front to back in order to try to keep the pickups from becoming uncovered. The oil pans are a work of art, and the Camaro pan and Corvette pan differ quite a bit for chassis fitment reasons. We have 6 quarts of oil available to us at reduced viscosity, an improvement over the old 5 quart high viscosity systems, but there are still limits. Here's is where the issue comes from. This will be a bit simplistic, but valid. Our oil pump is mounted at the front of the crank, a georotor design. The pickup extends into the center of the pan. At low RPM the oil pressure is actually lower than older engines, partly from lower viscosity and partly from reduced need 'up top'. The rockers are roller bearing'ed now, not the friction fulcrums of old and less oil is required up there to lube and cool. The pressure rises as RPM increases. The oil pumped up there under pressure and to other parts increases as RPM increases and has to drain back past the crankshaft to the pan to be channeled to the pickup for re-pumping to the engine. Eventually the pressure relief valve in the pump may operate to help control lower end starvation and help control the tendency of the pump to send oil to the higher parts of the engine faster than it can drain back. It can only drain back so fast. The provisions for drain back are placed where they would collect oil and as limited by design, allow it to drain back towards the pan. This is done strictly by gravity, splashing over other parts needing lubrication and cooling on the way, and eventually it gets windaged onto the sides of the block, cam area, cylinder walls, etc. by the whirling crankshaft and rods. The higher the RPM, the worse the windage and the more oil involved in it and unavailable to the pump. The demand for oil by the pump at some point is going to exceed the available and required supply.....BOOM! Performance drag engines are usually built with great attention to the drainback channels by porting and polishing them to improve return flow, special baffles added to the lifter valley area, and semi-circular screens added under the crankshaft swept area so that it throws oil through them back to the pan, and preventing pan oil from being sucked up into the windaged area and made unavailable to the pump pickup. Deeper pans are often added, or wings appended to the pan and capacities increased. Oil accumulators are added. Circle Track, NASCAR and other sustained high RPM motors receive even more special treatment such as higher than stock capacity dry sump systems. JMHU...