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Dale
Detrich
Attica,
OH
djdtrh@cros.net
The gearless hit and miss engine was the
first i.c.engine that i built, first reason that i built this
engine was that i did not have much in the way of tooling. i had a basic
three in one machine. second reason was that the plans were free, being
a five issue project in home shop machinist. the engine was designed by
Philip Duclos, and the plans were clear and easy to follow. the
engine has a basic vertical set up , except the drive between the
crankshaft and valves. intake valve is spring loaded atmosphere
operated, the exhaust valve is pushrod operated from a single lobe
cam. the two to one ratio between crank and valve is achieved by a
tumbling block on top of the pushrod. this block has two short arms and
two long arms, when the pushrod is lifted by the cam and one of the long
arms is in the up position the exhaust valve is operated. on the down
stroke of the pushrod , the block is rotated 90 degrees ,so the next
time the pushrod is lifted the exhaust is not operated. this tumbling
action pro
vides a two to one ratio between crank.
the engine has a spring loaded governor which keeps the engine at
aprox.900 RPM.
bore.. .750"
stroke........1.125" fuel
...............40 to 1 pump gas and 2 cycle oil ignition..........12
volt point operated the
engine with the tumbling block valve operation is eye catching and
fun to watch, the engine is now aprox six years old . the engine runs
trouble free, and some times for hours at a time
Copyright 2002, Florida Association of Model Engineers
and engine builder as noted above,
All rights reserved.