Charles Yates acquired an STC for the Cessna A & T188 series aircraft for the installation of a 300 HP Lycoming engine in 1990 The project was driven by a desire for better performance and reliability than the Continental 520-550 offered. In February 2009 the STC was sold to Sandy Ullrich.
The Lycoming powered Cessna’s are real performers. They are 135 MPH airplanes with anything under 180 gallons in the hopper. A 240 gallon load was demonstrated from a 2500 ft runway @ 75’ ASL for the FAA during certification but 200 gallons was a much more comfortable load. The airspeed is about 130 mph with more than 180 gallons.
The Lycoming IO-540-K and S series engines in an AG aircraft have a 1,500 hr TBO. With their flow balanced induction system the Lycoming engines provide an honest 300 HP. In addition they don’t have the cylinder, case & oil cooler cracking problems associated with the Continental 520-550 engine installation.
The Lycoming engine is easier to install than the original Continental installation. This conversion package comes ready for installation and provides more space between the engine and firewall for ease of maintenance.
The STC SA8343SW Approval package and Kit includes the following items.
A heavy duty engine mount manufactured by Ullrich Aviation is made of 1" 4130 steel tubing, of .058 wall thickness and is powder coated. The new heavy duty vibration isolators are manufactured by Barry Controls.
The new 2 large firewall mounted oil coolers with plenum ducts provide more than adequate oil cooling capacity in hot weather.
A new Stainless exhaust system designed with 2 individual headers that gives a longer service life and considerably less back pressure than the original Cessna exhaust system.
A new composite cowling designed for ease of removal and installation.
New throttle, mixture, and propeller control cables come with the kit. New engine baffles made of .060 aluminum and high temp silicon baffle seals.
All new hardware, engine mounting bolts, nuts, washers, screws, cowl fasteners, and Teflon type D fire sleeve hoses. (Teflon Type D hoses are not life limited by age.)
Exchange overhauled fuel flow manifold pressure gauge, new Electronic International digital tachometer, oil pressure & temp, EGT & CHT gages are provided for the Lycoming engine installation.
The new Hartzell 2 blade 86” propeller with spinner is specifically designed for this STC and gives better thrust and quieter operation than the McCauley 2 blade 86" propeller.
