[Roadsters] Cams

[Ronnie Day]

IMO, there are way too many variables to make blanket statements like one
cam/carb combo makes more power than another, unless specific parameters
are stated. Are we talking at 3K or 6K plus, or are we talking an
isolated/peak number? Is this "seat of the pants" or measured data? Throw
worn out carbs or a cam that's got some worn lobs into the mix and that's a
whole 'nother can of worms.

Given an engine in good condition, generally an SU equipped car will
produce better torque in the 2K to 4K range due to higher mixture velocity,
whereas dual throat side drafts (Solexes, Webers, etc)  really come into
their own around 4K plus. Both cases should include a cam designed to work
with the carbs and the timing tweaked accordingly, too. A total systems
approach, designed for specific goals is best, IMO. I will say that if
you're going to go with the Solexes, at least you have the OE configuration
as a good starting point. Start changing venturis (chokes) and jetting or
using Webers opens a whole new world of learning and spending money if you
want to get thinngs right

Reading Dana's original question, I'm wondering why he decided he need to
swap cams? If there are mechanical issues that need to be addressed, sure,
but working with the head design on the U and L series usually requires
replacing additional parts other than just the cam itself.

FWIW,
Ron