The engine compartment is accessible for inspection by removing the fasteners from the top and bottom cowling. The engine mount is constructed of steel tubing, and dynafocal attachment is provided to reduce vibration.

Sample Lycoming engine installation
Click here for full-size view

The engine is air cooled by directing air around the cylinder fins with a good baffling system. Air for the cabin heat option kit is also picked up from the nose cowling and carried through a SCAT duct to the muffler shrouds. A simple on/off air selector box directs the hot air into the cabin. Hot air for the carburetor air box is supplied by the right muffler shroud.

Engine Mount. The engine is attached to a dynafocal engine mount. The engine mount is made up of 4130N Tubing ¾" diameter with a wall thickens of .058" The dynafocal rubber mounts are standard off-the-shelf parts. The engine mount does not support any part of the nose wheel assembly.

Engine Cowling. The engine is surrounded by a top and lower cowl. It is one of the few parts on the aircraft which is made of fiberglass. Less than 15 screws hold both cowls together and to the firewall. A large oil access door is located on the top right of the cowl giving adequate room for oil checks. The opening at the front of the cowling is extremely large but very effective in keeping the engine cool on hot summer days.

The exhaust system is constructed of stainless steel and incorporates dual mufflers with optional heater shrouds to supply heated air for the cabin, windshield defroster, and the carburetor deicing system. Two separate mufflers make it easy and inexpensive to maintain. They are made of 321 type stainless steel with .035" wall thickness. The engine noise is less than 72 dB qualifying it for European noise regulations. The cabin heat shroud is around the left muffler and the carburetor shroud is around the right. The cabin heat shroud is easy to remove for muffler inspection.

The carburetor air intake box uses a standard Bracket air filter. The air intake box to the carburetor is steel and the rest is aluminum. The engine cowling is not attached to the intake box, making it easy to remove the cowl.

The new Lycoming engines are supplied with dual Slick magnetos. These new style magnetos only weigh 3-3/4 pounds each, and they are completely rebuildable with many up-grade kits available on the market.

The new SkyTech starter motor is also supplied with the factory-new engine. This is one of the newest starters on the market today, and is factory-installed by Textron Lycoming. It weighs less than half of the old type and increases the turnover rate of the propeller for better starting.

The alternator output is 70 Amps, which is more than enough for a full IFR avionics package including the standard night light package. It is factory- installed by Textron Lycoming, and is reliable and extremely easy to maintain.

The voltage regulator can be adjusted without removing the unit from the firewall. 

The oil cooler is mounted on the firewall and not on the engine baffles. The engine is equipped with a thermal bypass valve for colder weather, by-passing the oil cooler. In freezing weather a winter baffle can be added. The winter baffles can be installed and removed by simply removing the cowling and by installing less than 10 screws in the existing baffles and not the engine.

The Sensenich 76-EM8-0-54 fixed pitch propeller is all-aluminum, easy to maintain, and easy to replace and install. A Sensenich aluminum spinner is also available. It is held in place with 8 screws and if the spinner is removed, will not change engine cooling or performance of the aircraft.

The oil filter is an off-the-shelf item and is easy to replace and install. No parts have to be removed in order to service the oil filter. It is installed and approved by Textron Lycoming.

The black handled throttle control is used to adjust engine RPM. Springs are added to the throttle lever arm to ensure that the engine will go to full power if linkages should fail. The item is made from solid state materials and has a 3/16 inch diameter 10-32 threaded end with 8 degree swivel. 

The red handled mixture control is used to adjust the air-to-fuel ratio in the carburetor. The engine is shut down by the pulling the mixture control to the full lean position. In addition, the mixture control has a push button lock to prevent inadvertent activation of the mixture control. 

The blue-dotted carburetor heat control has two positions: pull out for ‘ON’, push in for ‘OFF’. The control cable has a .050 inch diameter stainless steel wire core in flexible metal casing with polyethylene liner.

The key switch is a standard aircraft type with the following positions: OFF, LEFT MAG, RIGHT MAG, ON, START. Overturning of the engine will blow the main master breaker before damaging the starter.

There are no cowl flaps or other special engine controls.

Zenair offers builders with complete firewall-forward kits for easy installation of the Lycoming O-360 engine in the Zodiac CH 640.  Typically, builders purchase and start assembling the airframe before purchasing an engine.