Many people have built the Ford's First Engine (1893) replica. Here are some links to information on those builds:
Neil Butterfield : Some nice pictures at this link. [Link no longer working.]
J. Bailey : Good pictures of individual parts and the finished engine. [Link no longer working.]
Flywheel - don't skimp on the flywheel weight, a good heavy flywheel is need to get the engine through the compression cycle.
Compression - this is a low compression engine, so any compression leaks may prevent the engine from starting.
Ignition - a Model T type buzzcoil works well with this engine.
Throttle - there isn't one! Engine speed is somewhat controlled by the fuel feed, and is essentially self-limiting at about 400 rpm.
[Note: Click on any photo for a larger view.]
The completed engine.
This photo shows the timing gears , exhaust valve cam, pushrod foot, and the timer contact touching the roll pin extending from the cam.
The fuel reservoir, intake valve, spark plug and exhaust valve are shown in this photo.
The ignition system includes a 6V Gelcell and Model T buzzcoil.
In 2011, at the annual meeting of the Early American Industries Association in Dearborn Michigan, I displayed my working replica and was awarded this plaque.