FLO Headworks: 
Performance Specialists for
your Harley-Davidson® Motorcycles





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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 eliminate detonation.

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 particular cams

Check out the flow chart accessible from this page, and you’ll 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 e-mail us.

Related Articles

HD Porting Secrets

Dual Plugging

Tooled Finish

Super Port Flow

A Sportster 1200  head with Super Port Flow

Test Data

Sportster 1200/Buell  Data Sheet

Sportster 1200/Buell  Flow Chart

For Prices See

Super Port Flow


© 2000-2014, FLO Headworks. Contact Perry Kime at 805-481-6300 or via e-mail.
FLO Headworks, 1150 Pike Lane, #2, Oceano, CA, 93445.
All rights reserved. All prices subject to change without notice.
FLOHEADWORKS.COM and Perry Kime have no affiliation with Harley-Davidson® Motor Company. Trademarks and model names are the property of the trademark holders.