7 Nov 2014

My brother got his LS-3 powered Stalker tuned today: 416 hp and 398 torques as Clarkson would say. Scott claims that on warm tires, it hooks up in second, which should certainly provide hours of entertainment! One more entry about dry sumps then issue will be set aside. I talked to a buddy who pointed out a condition that he feels is the single biggest reason to have one: In an OEM setup, oil in the pan is picked up by the pump and distributed throughout the engine, with the most important destination being the main bearings. The oil isolates the bearing halves from each other and with pressures of many thousands of pounds, it’s important the two never touch else bearing damage and eventual engine failure are soon to follow. The problem starts with the engine being run at high rpm. Air becomes entrained (mixed) into the oil by the spinning crankshaft to such an degree that it becomes an emulsion, a milkshake-like mixture of oil and air, with air constituting up to as much as a third of the volume (in fact, dry sump tanks are recommended to be filled only to ~60% capacity due to oil foaming potentially filling the rest of the tank). (As an aside, consider adding 30-40% volume to the oil mass, which raises the level enough that it’s now constantly being beaten by the crankshaft, which only exacerbates the problem.) The emulsion is sucked up by the pump and sent to the main bearings, where the normally-incompressible oil film has been contaminated with air. The thousands of pounds of pressure is now able to compress the oil/air down to a dangerously thin layer and greatly increases the chance of bearing damage. Even worse, if and when the pump sucks air, oil pressure drops and the entrained air bubbles expand to about double, effectively doubling the amount air in the oil. This situation of having the oil system contaminated by entrained air cannot be fixed by adding an extra quart or an Accusump, but others disagree. So be it.