Crankcase ventilation, engine ventilation
The gases produced during combustion find their way out not only via the exhaust, but also past the piston and into the crankcase. As a result of the up and down movement of the pistons, the volume of the crankcase is also constantly changing. To ensure that every gasket seals permanently and stays in place, the inside of the crankcase needs a connection to the outside to compensate: the crankcase ventilation.
The crankcases of Harley-Davidson V-Twins do not vent directly to the outside, but via a rotary valve first into the gear case, i.e. the section in the engine case where the camshafts and other gears are housed. The rotary valve has the advantage that its movement is precisely controlled in relation to the crankshaft. This allows to create a slight vacuum in the crankcase, which supports the engine seals.
If you also want to create an advantageous vacuum in the timing case, you can do this with a small accessory: a breather valve. Finally, breather filters ensure that any dirt remains outside.
Have any questions?
Our service team will be glad to help out: Mondays - Thursdays 08:00-17:00 CET, Fridays 08:00-16:00 CET, Phone: +49 / 931 250 61 16, eMail: firstname.lastname@example.org