After much time and flow testing, we are
happy to announce the release of our high performance cylinder head
modification for late-model Sportster engines.
The process of events that led to a
significant increase in the flow characteristics throughout the entire
range of valve lift is lengthy and tricky to say the least.
Our flow bench techniques have enabled us
to improve the low-lift flow of both the intake and exhaust ports,
giving the engine a smoothly tuned effect, even with some of the more
radical cams. The high-lift flow at .500 has been increased in the
exhaust port by 28% and by 19%in the intake port, providing an exhaust
to intake ratio of 84% at 500"
lift, which is up from stock average of 78%.
During the process, a large amount of
metal is removed from the ports using our patented Tooled Finish, to
give maximum atomization of the incoming fuel. The seat pockets are
polished with a radius up to the valve seating area. The combustion
chambers are matched to your bore size and polished to give the most
effective flame travel.
Dual spark plug conversion is the
finishing touch to give your engine its full power potential and
Our valves are handmade in-house from
21-4N stainless steel with polished tuliped heads. The backside is
machined with a . 750" radius to increase flow characteristics and
nitrided along with the stem to minimize wear.
The valve seating area measures
.060"wide on the exhaust valves and .045"wide on the intake
valves. The head diameter has been increased to 1.562"on the
exhaust and 1.812"on the intake.
This high-performance cylinder head
modification package includes:
Matching and reshaping the intake
manifold with our Tooled Finish to atomize the incoming fuel
Hand lapping the head gasket surface
Glass beading or painting
Testing valve springs
Assembly with our all Teflon valve
stem seals to the specifications required by manufacturer of your
Check out the flow chart accessible from
this page, and youll see the dramatic improvement in breathing. These
heads, like all FLO Headworks products, are guaranteed for one year on
street driven motorcycles.
Our work and products are guaranteed for
one year. For an estimate on your particular application contact us
directly by telephone at 805-481-6300. Or you can