GAMIspec Engines Get Cool Upgrades (Literally)

Blueprinting engines used to be—and still is—a thing in automotive hot rodding and that's a bit of what General Aviation Modifications is doing with improvements to its GAMIspec Continental engines. They'll include taperfin cylinders, needle bearing rocker arms and upgraded cooling. The engines perform better, but GAMI intends them to be more durable. The mods are also available separately for many Continental engines.

Both Continental and Superior Air Parts offer taperfin cylinders, which have a reduced cross section in the fins in the steel barrel portion of the jug. That allows reallocation of more air to the aluminum cylinder heads, where cooling is most needed. The GAMIspec engines include upgraded Liquidair cooling baffles configured to work with taperfin cylinders, thus improving overall cooling efficiency, according to GAMI President Tim Roehl.

Premature loss of compression has been a recurring problem in Continental engines, a shortcoming that's addressed with needle bearing rocker arms that replace the standard bushed arm. "The needle bearing rocker arms have demonstrated significantly reduced wear compared to the standard rocker arm bushings. The wear on conventional rocker arm bushings tends to aggravate valve-guide wear in those big-bore Continental engines by side-loading the top of the valve during operation," said George Braly, head of engineering for GAMI and Tornado Alley Turbo.

The rocker arms are approved for use on specific models of IO-470, IO-520 and IO-550 engines, both naturally aspirated and turbonormalized. GAMI/TAT says availability is targeted for the summer of 2019. These new mods, exclusively available from GAMI and TAT, are designed to improve performance and durability in the 300-HP engine used in many Beechcraft Bonanzas.

See GAMI/TAT at Sun ‘n Fun in booth A65.