The EL-740 Air Compressor is two cylinder, air or water cooled, and engine lubricated. It can be base or flange mounted.
The air compressor has a rated capacity of 7.4 CFM which is the displacement in cubic feet per minute (CFM) at 1250 rpm.
The EL-740 Air Compressor is designed with a ball-bearing at the front (the shaft end of the air compressor) and a sleeve-type rear bearing. Several models carry ball bearings front and rear. The air compressor is designed with a one-piece crankshaft.
Pistons are made of aluminum alloy. Each piston has three compression rings: one in the top groove, and two in the second groove (some older style air compressors have only two compression rings; one in each groove). In the groove below the wrist pin (the oil rail groove) is one expander ring and two oil rails. Thrust buttons are used on both ends of the wrist pin to retain the pin in the piston rod.
Rod bearings are replaceable insert type.
All valve components are installed within the head. The exhaust valves use a screw-in, spring-loaded, disc-type assembly located in the bottom of the head. The inlet valve guard and valve are pressed into the inlet cavity in the bottom of the head.
The unloader mechanism components are housed in the unloader assembly which is bolted to the top of the head. The unloader pins extend from the unloader assembly, through the cylinder head to the inlet valve cavity where they hold the inlet valves open when the air system is at maximum pressure.