Machined pistons?

I’m rebuilding a 1300 Crossflow for sprinting to the following specs: gas-flowed head with larger inlet valves, BCF2 cam, twin 40 DCOEs, and a Mexico-style exhaust manifold. Will I need to have pockets machined in the pistons with the BCF2 cam? What ignition and carb settings should I use?

Finally, how much bhp do you think I could expect from this spec? Keith Jefferson

UK

A With the BCF2 you should have decent piston-to-valve clearance, but you should check it anyway, using a blob of plasticine. It’s good practice to check this clearance with any camshaft you are fitting.

Set the timing at 6 degrees BTDC, and try the following jets for the carbs (taken from our well-thumbed copy of Tuning Four-cylinder Fords). Choke: 33. Main jet: 130 Air corrector: 190 Emulsion tube: F16 Pump: 40 Idle: 45F9 Auxiliary venturi: 4.5

Both the timing and jet selections are guides to get you going, and a trip to the rolling road is needed for ultimate calibration. Horsepower? You’d be doing very well if the engine made 95-100 bhp.