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FLO Headworks is happy to announce the release of a complete new line of totally trick valve spring kits for Harley-Davidson Big Twins from 1948 on and Sportsters from 1957 on, and all Buell models.

New technology has enabled us to reduce tolerances in the valve spring manufacturing process to less than one tenth of one thousandth of an inch, consistently. This improved tolerance results in a closer interference fit between the inner and outer springs.

Some aftermarket spring manufacturers have used excessive interference in their replacement springs, which makes for unwanted spring characteristics. Others have used friction-reducing coatings to reduce heat, but this approach adds its own problems.

At FLO Headworks, we have reduced the interference fit down to .0025”, resulting in the best of both worlds—not too loose and not too tight, just right! These new springs run so cool that they don’t even need coating.

To make sure every set of our springs meets our high standards, we have assembled a valve spring testing device: the Variable RPM Spin Fixture. Originally designed by a legendary camshaft designer, this gizmo tests valve train components using a strobe light and can catch the most minute imperfections.

Here are the numbers: Evolution Big Twin, Evo Sportster 883 and 1200, and Buell valve springs assembled at 1. 812" will have 125 lbs. on the seat, 280 lbs. at .500" lift, 360 lbs. at .680" lift, and coil bind at 1.060".

Shovelhead and Panhead valve springs assembled at 1.500"will have 135 lbs. on the seat, 315 lbs. at .500"lift, 350 lbs. at .575"lift, and coilbind at .875". The valve spring retainers are machined from grade 7075 aluminum alloy. Stock keepers and lower collars work well.

Ironhead Sportster springs come in two different sets. The High Lift set assembled at 1.375" will have 125 lbs. on the seat, 310 lbs. at .500" lift, 350 lbs. at .550" lift and coil bind at .750". The High Performance set assembled at 1.375"will have 100 lbs. on the seat, 230 lbs. at. 450" lift and coil bind at .875". There is no need to change from the stock collars and keepers which work very well.

FLO Headworks high performance valve springs are manufactured from the very highest quality chrome silicon wire, shot peened, heat treated and heat set. They are inspected during every step of the process to insure our stringent specifications.

The valve spring retainers are machined from grade 7075 aluminum alloy. The keepers are machined from grade 4140 chrome moly steel, heat treated and machined at a 30-degree included angle. The lower spring seats are machined from premium grade 4140 chrome moly steel and heat treated to minimize wear. This valve spring kit comes complete as pictured.

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.


FLO Headworks Valve Spring Kit for Twin Cam, Evolution Big Twin, Sportster and Buell

Twin Cam

Evolution Big Twin, Sportster, Buell

Pushrods by FLO Headworks

All our pushrods are manufactured using seamless chromoly tubing, centerless ground for precision construction. The pushrod ends are hardened stressproof 1144 steel.

The screws are made from chromoly 8740. The nuts are made from  hardened 1018 steel with 5/16x32 NEF threads for maximum strength and durability.

Shovelhead, Panhead, Knucklehead

Shovelhead, Panhead with High Lift Kit

Ironhead Sportster High Performance


Ironhead Sportster High Lift

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© 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.