Installation of Lycoming GO-435-C2B, GSO/IGSO-480 and GO/IGO-480 series engines with Hartzell HC-A2V20 and HC-A3V series propellers.  New Nacelle and engine mount, modified front and rear spar and firewall as well as associated systems, STC SA615NW.


The Simuflight Lycoming engine conversion is the most popular engine conversion available and represents the majority of all conversions currently in service.  This conversion utilizes the GO-435 and GO/IGO/GSO/IGSO-480 engine series.  The geared Lycoming GO-480 engine allows a reduced propeller speed, 2170 rpm at engine speed of 3400 rpm, with reduced noise and increased propeller efficiency as a result.· Due to the higher mount of the Simuflight engine conversion, larger propeller diameters, 89 inches can be installed on the Simuflight conversions providing maximum efficiency from the propeller. The Simuflight conversion provides exceptional off the water performance, approx 980 ft at gross and a Sea level climb performance of 1200+ fpm at gross.  For typical flying you can expect water runs of less than 900 ft.

The main features of the Simuflight engine conversions are as follows

Cowling - The Simuflight engine cowling is fabricated from two original Seabee aluminum cowlings that are modified to form on single piece weighing only 22 lbs.  The cowl is hinged at the forward end and opens with the release of two lever fasteners - one at each side.  This configuration provides for easy engine access and maintenance and simple removal of the cowling for major maintenance operations.·Note: the cowling is not part of the engine kit.  This can be built at our shop and shipped to you to ensure that cowling is correctly assembled.  Contact us for more information on this item.

Engine Mount - Is made almost completely of aluminum and weighs 14 lbs.· It has been statically tested and approved by FAA.  The rubber "Lord Mounts" are mounted at 45° angle to the engine vertical.· The Simuflight mount is designed to transfer engine loads into the firewall and rear cabin, as on the original Franklin engine installation.  It also sets the engine forward of other engine conversions helping with the aft CG typical in a Seabee.

Exhaust System - Uses existing Seabee collectors which are welded to Lycoming flanges, to attach to the cylinders.  The exhaust is routed forward from the cylinders and exhausted upward over the center of the wing at a 45° angle, to prevent exhaust burn stains and to reduce noise.  You can make this part or save yourself a lot of trouble and just order the exhaust system kit from us directly.  Note: the exhaust kit is not part of the standard kit.

Structural Modifications - The rear firewall section (triangular area aft of the rear spar) is lowered approximately 10 inches to make room for the carburetor or fuel injector unit.  An access door is provided on the left side for removal or inspection of the carburetor components.  The rear spar is strengthened on both sides directly under the engine mount.

Air Filtering - Carburetor induction air is filtered at the intake located forward of the engine to provide the coolest and cleanest pickup air.

Propeller - Hartzell constant speed and reversible 3 blade prop.· The blades are 9333, which are cut off four inches at the factory to give 89 inches of blade length.  The propeller in combination with the gear reduction is the true key to the performance of this engine conversion.  We are turning a very large blade at a slow and very efficient speed.  Horse power is not the key to the performance of this conversion.  Combined with our wing extension and drooped wing tip kits this is kit will realize is maximum performance.

Gross Weight - The Simuflight engine conversions allow gross weight increase of Seabee from original 3150 lbs to 3250 lbs.


  Franklin Simuflight Conversion
Takeoff run on land 800 ft. <800 ft.
Takeoff run on water 1000 ft. 700 ft. *
Landing run on land 400 ft. 400 ft.
Landing run on water 700 ft. 700 ft.
Max level speed at Sea level 120 mph 130 mph
Normal cruise at 75% power 103 mph 115 mph
Stall speed clean (Vs) 61 mph 61 mph
Stall speed landing configuration (Vso) 58 mph 58 mph
Rate of climb (sea level) 700 fpm 1200+ fpm
Range 6.25 hours 5 hours ****
Fuel consumption 12 gph *** 11.5 gph **

*     This is the typical water run, the conversion was certified at gross for 980 ft. of water run.
**    Based on 15 gph fuel consumption.
***  Based on 12 gph fuel consumption.
**** Leaned to 62-65% power at 6000 ft. you can expect fuel consumption to be approx 11.3-11.6 gph.

STC SA615NW - Installation of Lycoming GO-435-C2B, GSO-/IGSO-480 series and GO-/IGO-480 series engine with Hartzell HC-A2V20 and HC-A3V series propellers; new nacelle and engine mount; modified front and rear spar and aft firewall; and associated systems.

Price: Contact us 
Availability: 3 -5 weeks

STC SA5684NM - Installation of Lycoming GSO-/IGSO-480 series engine; Hartzell HC-A3V20 propeller; new nacelle and engine mount; modified front and rear spar and aft firewall; and associated systems.··While this STC is still produced and supported we recommend the kit defined by SA615NW.