Reverse rotation engines

The Corvair engine can be set up to run in either direction.

AD for distributor and oil pump drive gears

Roy Szarafinski posted this AD about issues developing on the distributor and oil pump drive gears on reverse rotation engines.

Two engines have exhibited abnormal wear characteristics of these gears. Wear characteristics consist of a blued distributor shaft at the distributor drive gear along with metal transfer from the brass crankshaft gear to the steel distributor drive gear, during/after initial engine break in. Preliminary investigation reveals a 60 thousandths inch larger pitch diameter between original standard rotation and the replacement reverse drive steel distributor gear, which results in a pre-loaded gear condition. It is believed that reverse rotation parts purchased prior to 2006 are unaffected. The run time on the compromised engines is one and three hours respectively. Engines were built by unaffiliated entities and no catastrophic failures resulted. It is believed at this time that the only item of concern is the steel distributor gear. This gear will have a wider chordal tooth thickness profile compared to the original gear. This can be visually verified by comparing the tooth profile with the original placed upon the reverse gear.

Resolving this issue is currently ongoing. Affected builders can contact Roy.