Elf Reed Valve 4
| Name | Elf 40 Series 4 | Designer | Dan Calkin |
| Type | Horizontally opposed, four cylinder, reed valve, spark ignition engine | Capacity | 4.8 cc |
| Production Run | unknown | Country of Origin | USA |
| Photo by | Ron C | Year of manufacture | 1950's |
Notes:
Dan Calkin's Elf design was inspired from a perspective of modularity. His range included single, 2, 4 and 6 cylinder engines which shared the same cylinder/piston/rod assembly, front and rear crankcase casting, timers and other minor parts. To make the multi-cylinder "boxer" engines, he merely needed additional crankcase center castings and an appropriate multy-throw crankshaft. The engine shown here is a relatively late model flat-four, made after the change to reed valve induction (from the "Goose-Egg" side-port four). Later still versions of this engine were fitted with glow-plug ignition, but this one retains his last version, "open" dual breaker assembly.
If you look very closely, you can see where the mounting lug on the front crankcase cover has been ground away (needed only for single cylinder engines). Also noticable are the "turned" cylinder fins produced by cutting rather than casting the top three fin gaps. This change occured late in the 1940's. The odd spring-thing hanging off the needle valve, while well made, is not original I believe.
