SPARK PLUG LOCATION TESTS, LION CYLINDER HEAD
We have performed a series of dyno tests to determine the spark plug location that produces the most horsepower on Charlie Yapp's Lion cylinder head. The iron Lion 2 cylinder head was available with both plug locations, as is the current aluminum version of the Lion 3 head. One spark plug location is over the valves, the other is over the cylinder.
We ran tests using one of our Street Rod Model A Ford engines. The engine was equipped with the Weber 32-36 carburetor & intake manifold, a cast iron header & Smithys muffler.
We ran the engine with the spark plugs in each location, varying the ignition timing to determine the maximum power.
Each dyno run lists the tuning combination.
The final result is the spark plug location over the valves (passenger side) with 28 degrees ignition timing makes the most power from 1300 RPM's to 2500 RPM's. The spark plug located over the cylinder (drivers' side) makes more power above 2600 RPM's with 26 degrees timing.
VIEW DYNO RESULTS