Original Posted By: dralle(at)matronics.com (Matt Dralle)
Subject: Pietenpol-List: Rocker armsYou are correct that not all rocker arms are the same. Most aircraftengines do have exhaust rocker arms with a hole drilled in them to allowoil to be sprayed on the exhaust valve stem for cooling purposes. So thedrilled rockers are exhaust ones and the non-drilled are for the intakevalves.John Langston________________________________________________________________________________