Cam Synchronization
The Camshaft in the Ford Kent Crossflow engine is located in the engine block. This makes it very time consuming and demands lots of work to change the cam type.
With the Natural Aspirated (N.A.) engine, it was almost too much work to do cam tuning experiments.
Moving to Turbo tuning, this issue is gone as the camshaft should go back to a non overlap cam and be as standard as possible in all configurations. Overlap will result in blowing the fuel mixture through the engine directly into the exhaust system. Initially i did that with the result of having 2500ppm fuel in the exhaust gas, some 10% higher fuel consumption and lower torque/power.
With the fuel injection, I initially went for a semi-sequential solution. I didn’t spend the time to make a Cam Sensor system to indicate TDC compression of cylinder no 1. I have also heard that it wouldn’t do any difference in performance, which I later verified.
Aiming for higher and higher power, so far, five (5) different turbo configurations have been tested. The highest output level was up to 300 HP, which required a lot of fuel. Bosch, green 0280150558, injectors at 440ml/min (42 lb/hr) was/are being used but with increased pressure.
With those, the problem of stable fuel delivery arise at idle and at low vacuum over the rpm range.
No getting round it, I had to develop a Cam Sensor unit, and move to full sequential fuel injection. This will double the injector on-time, as it runs the injection over two crank turns and not for every turn. With double fuel injection time, the injector minimum turn-on/off time (typical 1.6mS) is less important. I reduced the min switching time with a 15 volt dc/dc supply.
The Cam Sensor unit was made of an old Motorcraft distributor unit. A steel wheel with a tooth notch was made and mounted on the axle. A Hall-Effect sensor from Honeywell ‘2AV54’ was used. Everything was assembled, aligned and tested to give a perfect trigger signal, that should have the rising edge be between 180 and 6 deg before TDC of the compression for the cylinder number one cylinder.
With the full sequential set-up and the mods there are now no problems with the 440ml/hr injectors at idle or low vacuum (low MAP) over the rpm range.
