The OEM LS dry sump systems as delivered is suitable for general driving conditions, but suffers from 1 modest deficiency and one serious failing which can lead to significant engine failure under sustained severe driving conditions. Our solutions for these problems with the OEM system elevates the effectiveness of the OEM components to the level of the delivered vehicle even when modified for additional handling and acceleration at a modest cost and without replacement of any of the OEM components.These solutions consist of an oil pan baffle and trap assembly with it's own unique windage tray, and a baffle and vent insert for the OEM tank. This should be suitable for most installations, although there are always levels of beyond which a traditional dry sump system would be required.
The primary failure of the OEM system is to provide consistent return of oil from the engine sump to the tank. The open, unbaffled bowl shape of the sump fails to deliver the oil accumulated in the sump to the scavenge pump pickup when the vehicle is driven for an extended period in an aggressive manner. It's a bad wet sump pan. Under acceleration and deceleration oil runs up the ends of the sump, climbing the ends of the sump through the windage tray and right into the reciprocating assembly. Similarly under cornering the oil climbs the sides of the pan with the same effect. If you do the math, that assembly at 7000 rpm is a 200 mph tornado at the perimeter. Oil coming in contact with these components is atomized, making it impossible to scavenge. At the same time the energy imparted to the oil molecules to move them out of the way of the crankshaft is converted to heat. As this oil becomes trapped in the crankcase, not returning to the tank, the pressure pump continues to push more oil into the engine, and draining the tank. Eventually the oil level in the tank drops to a point where the pressure pump pulls air, causing eventual damage and then failure of the engine due to oil starvation.
The AVIAID solution is the same that we have been using in the road race, circle track drag race and marine pans since 1961. A trap door assembly surrounding the pickup holds oil around the pickup so that it can be scavenge back to the tank. A new windage tray replaces the stock part, improving oil fallout from the crankcase, promoting coalescence of the oil back into a scavengable liquid, and providing a relative calm area where oil can re-coalesce and be scavenged back to the tank.
The oil tank insert completes the work that GM has done in building a dry sump tank. We provide the baffle and venting mechanism that was left out of the OEM tank. The baffles in the assembly help stabilize the oil in the tank, helping it resist the vehicle motions that toss it around the inside of the tank, and providing more consistent coverage of the tank pickup in the bottom. One symptom mentioned repeatedly by Corvette drivers is the tendancy for the engine to lose oil pressure during a sustained left hand turn. This is a direct result of air siphoning through up to 3 inches of oil into the tank pickup when the level has been lowered as a result of the inability to recover oil during sustained hard driving. The pickup is essentially a hole in the bottom of the left side of the tank when viewed from the driver's seat. In a left hand turn unbaffled oil tends to climb the right side of the tank due to the centrifigal force of the turn. Do it long enough with a lowered oil level in the tank and you suck air. Additionally oil flowing across the baffle surfaces tends to release air that is trapped in the oil. Additionally oil sloshing around the tank will have a tendency to be carried out of the tank by the natural flow of air pumped out of the engine into the tank. This oil carries over into the intake manifold through the OEM venting system, fouling the intake plenum and intake air charge.
The AVIAID solution puts baffles into the tank to help combat excessive movement of oil in the tank. It also helps break up oil siphon at the pickup, and maintains a more effective cover of the pickup with oil under all operating conditions. Additionally a defined and controlled vent path is provided out of the tank making effective use of the air/oil separator components in the baffle and tank to reduce or eliminate oil carry-over into the intake.
A relatively simple, passive oil control system requiring no replacement or reconfiguration of OEM components and maximizing the effectiveness of the factory system withing the limitations of those components and suitable for all but the most severe engine lubrication requirements. |