Extreme Engine Tech – Technosquare’s Monster Naturally Aspirated Toyota 4AG – Part 3
When we last left the Technosquare crew, they had completed the stroker 4AG engine’s bottom end and assembled the cylinder head. Now it was time for the engine’s final assembly and installation into an AE86 time attack car.
The Barnes dry sump pump has one pressure stage and two scavenge stages. The pump is belt driven from the crank. The TRD oil pan is very thick and greatly strengthens the block.
The first issue to address was the lubrication system. As the 4AG has an iffy lubrication system, mostly due to very fragile oil pump gear rotors that become marginal above 8000 rpm, a dry sump system is essential for engine longevity. The 4AG also pushes the demand on the oil system to high levels. It has a marginal amount of bearing area for high rpm operation and any air entrapment in the system or fluctuation of oil pressure can cause failure at high RPM.
Toda 4AG adjustable cam timing gears are used to dial in the cam timing, a critical step in tuning any full race engine. The lobe centers are currently set at 98 degrees intake and 102 degrees exhaust.