This site uses cookies. The cookies we use are essential for parts of the site to operate. You may delete and block all cookies from this site causing sections to not work.

Dealer Locator

My Garage




S&S Cycle logo

UL Cylinders from Flathead Power®

S&S is pleased to announce the availability of cylinders for 80" UL models.

UL CylindersThe perfect match for our popular UL heads. These cylinders come fully machined with guides installed and valve seats cut and lapped on our precision CNC equipment. The finished cylinders are then given a rich coat of high temperature black powdercoat.

Authentic to the closest detail, the cylinder set comes with valves, springs and gaskets – ready to assemble! Or get the kit, which includes everything in the set, plus cast pistons fit to factory specifications.

We've even made improvements to the original design while remaining true to the retro look. A taper has been incorporated into the exhaust ports for improved exhaust pipe retention.


  • 1937 – 1941 UL 80" engines
  • 1937 – 1948 UL 74" engines (upgrades to 80")

Features and Benefits:

  • Authentic 13 Fin Design With Stock-Like Markings
  • 3 7/16" Bore
  • Improved Modern Gray Cast Iron For Superior Durability
  • Comes Complete With Valves, Guides, Springs And Gaskets
  • Upgrade 80" Pistons Also Available
  • All Components Are Stock Compatible
  • These Cylinders Are Made In The USA


UL Cylinders

Set for 1937-'41 big twins (without pistons) MSRP $1,689.95 910-0166
Kit for 1937-'48 big twins (with pistons) MSRP $2,074.95 910-0169

S&S® Replacement Cast Pistons

Oversize Part No. Replacement Rings
Standard (3 7/16") 920-0013 940-0006
+.010" 920-0036 940-0007
+.020" 920-0037 940-0008
+.030" 920-0038 940-0009
+.040" 920-0039 940-0010
+.060" 920-0040 940-0011
MSRP $164.95 $36.95