Let me present you my very first I.C. 4-stroke engine.  This "WEBSTER" engine was build following the drawings from Joe Webster and some modifications were applied. 

     

It is horizontal, air cooled, single cylinder with automatic inlet valve and cam operated exhaust valve.  Cylinder head, cylinder fins and valve chamber are made from aluminum alloy.   Cylinder it self is from grey cast-iron as well as 2 piston rings of my own construction.  I have spent some long hours to get good rings.  First problem was to get good quality cast iron.  I was trying to follow the Bob Shores method to machine the rings but each time as I heated them up, despite of using holding fixture, they were sealing really poorly..So I choose different procedure -instead of heating opened rings, I have turned rings of a larger diameter then saw a gap with Dremel tool.  Then, I simply close the ring and lock it to fixture on the lathe to turn it down to a required diameter.   Result is very good.

Also lapping the cylinder was a task for a newcomer –but it came out perfectly.  Gear cutting was a pleasure with heavy duty dividing head attached to my milling machine.  There is 20 tooth steel wheel and 40tooth brass wheel –module 1.  Valves are made from mild steel, valve guides from brass.  Exhaust cam was milled according to drawings–opening slightly before BDC, closing exactly at TDC.  To reduce friction to minimal level, I have used ball bearings everywhere – main crankshaft bearings, camshaft bearings, there is also small ball bearing on the rocker arm.   Not very traditional is pressed ball bearing in the connecting rod’s bigend.  One of my additions is adjustable breaker plate,  I’m also considering crank driven cooling fan and dynamo.  For now, I'm using commercial carburetor from glow 6.5ccm engine, which is rather large –as I can not open it to more than 1/2 throttle.  Today, engine has totally over 10 hours of running time. I took it twice to a engines related events and it is a great discussion starter.. This was a great project to build !  It was very rewarding moment as I cranked it for a first time! This was at 11:44 pm on New Years Eve 2005 –so I just made it as planned

                     

 

Please, visit Joe’s page http://cablespeed.com/~jbwebst/WEW/Gas_Engine.html to read his story and see more "WEBSTER" engines.