Piston Rings

A demanding sealing job in the cylinder: piston rings

Piston rings for all Harley-Davidson V-Twin engines from 1929-1999, preferably from Hastings (quality manufacturers such as S&S also source their rings from Hastings). Hastings piston rings stand for consistent quality since more than 100 years.

Are Hastings piston rings ready to install?

Yes, our piston rings are ready to install. However, because pistons and cylinders come from different manufacturers, you should always push the rings into the cylinder bore before fitting them to the piston. Insert straight (axially with the cylinder) a few centimeters (using the piston as an aid) and measure the ring gap. Hastings recommends 0.0035" per 1" cylinder bore. Example: a Shovel cylinder has a 3-7/16" bore, which corresponds to 3.4375". Times 0.0035" equals 0.012" ring gap (= 0.3...0.31 mm). A 30 mm feeler gauge must therefore fit through very easily.

How do you install piston rings on the piston?

To avoid damage and breakage, either use a quality brand of piston ring pliers or rely on your fingertip feeling: Spread the piston ring gap with your thumbnails and support the ring with several fingertips around the circumference. Spread just enough so that the ring slips over the piston. And always from bottom to top. So first the oil scraper, then the 2nd piston ring, then the top one. Sounds logical, doesn't it? But it should be mentioned here.