4Piston Racing built an upgraded version of their K24-K400 motor for a customer competing in 3-hour and 6-hour endurance racing. The engine build starts with a ductile iron sleeved block, lightweight Winberg crankshaft, Saenz Performance titanium rods, and lightweight short-skirt Wiseco pistons. On top goes a ported “Pro 163” 400 cfm head with 4Piston RR4 billet camshafts and PAC valve springs. Lubrication is provided by a 4Piston ported oil pump. Luke Wilson from 4Piston Racing estimates the engine is good for approximately 380 hp. Watch the engine be built in the video below.
Source: 4Piston Racing