Picture below are the camshafts from a PIPO rallycross 2.0 turbocharged engine (85x88mm), max intake pressure is 4.5 bar absolute, 4 valve head, 32.5mm intake, 28mm exhaust, max rpm 8500. The engine is intake air restricted, and also restricted by regulations is the max intake valve lift (12mm). Tappets are domed, have a diameter of 31mm and weight 18g each, valve springs (2, with a slight interference) have an increased on seat tension to keep valves closed when pressures in manifolds is highest.
Power curve is flat from 5500 to 7000 rpm producing 600HP. Intake pressure at max torque is 4.5 bar @4500rpm absolute, falling to 2.9 bar @7250rpm (due to the intake restrictor).
In the picture can be seen the big difference in angle between intake and exhaust cams even being this a turbocharged sport engine, and the almost flat nose of the intake cam (due to regulations). Also note the little concavity of the cams ramps (because the domed tappets).
- SNO Director, Spain branch, Barcelona
- '90 2.0 Spider -- '93 164 QV -- '93 155 2.0 TS -- '02 156 2.5 V6 -- '?? FMG 3.8 Project
Last edited by FMG_V6_btb; 02-16-2018 at 03:24 AM.