Timing gear comparison .
Early vs late
(cam timing retarded 8 crank degrees)
click for the big picture
click for the big picture
Starting in 1972 ford used the
retarded crankshaft sprocket,
Pictured at right..
Just changing the timing set on a
later model 429/460 to the early
style will help low end torque and
response. The difference is
pronounced!!
The stock camshaft is designed to
peak around 4,500 rmp or less. The
BBF is fussy about intake opening
point. Stock is 16* BTDC. The
retarded sprocket makes it 8*
BTDC. Most high performance
engines seem to run best with an
intake valve opening point of
around 41* BTDC
Remember to reset ignition timing
after changing the timing set.
When installing a higher
performance cam
always use the early
straight up timing set
.
It has been my experience that when using an early timing set on a later
model vehicle with the smog cam that the low end response is improved
but the high end HP suffers as the power band is moved down some 500
RPM. The specs on the smogger cam were changed to accomodate the
retarded timing set. Always use the early timing set when changing cams.