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.