The Marion 25

 

The Engine

Not much is known about the Marion Machine Foudry & Supply Co. The Marion 25 is one of three models supplied by this company, there were the 10hp, 25 hp and 35hp. All were more or less scaled from the same design. The engine is a standard four stroke design with a side shaft operating the exhaust valve, the governor, and aWico magneto.The side shaft is driven from the crankshaft by a set of 30 deg./ 60 deg. helix gears set at right angles.

An interesting feature of this design is the way the intake and exhaust use box like appendages to house the valves. The '25 weighs a massive 7980 lbs. and ran at 180 to 200 rpm at rated hp.

The engine shown above was taken fron an oil field in Texas, where it ran the pumps for 12 wells. It currently rests in operating condition at the TEDTEA grounds in Temple Texas. Come see it run each October: TEDTEA

The Model

It has been a long time comming, but it has been a rewarding and educational experience. The model is made at 1/5 scale of the Marion 25 hp engine shown above,. Every effort was taken to preserve detail and functionality of the original engine.

Shop Tools

This engine prototype has been machined in a 9x20 lathe, 8x28 MillDrill, and drill press, with a few exceptions. The Flywheels will require at least a 12" gap bed lathe, or could be machined in the mill drill with a rotary table. The cylinder liner and water jacket require a 12" lathe.

Some Statistics:

Bore 2.375"

Stroke: 3.7"

Flywheek Dia: 13"

Over All Length: 24.5"

 

The Engine Kit Includes

The Castings (Cast Iron) water jacket, cylinder liner(includes matl for piston rings), head, head cover, exhaust box, intake box, mixer, governor bracket, ignition bracket, rocker arm, rocker arm bracket, rocker arm bracket bearing cap, sideshaft bearing, sideshaft gear grease cup, engine base, 2 water flanges. 2 crankshaft bearing caps, 2 flywheels, and the piston

Note: Due to the requirement of having to make special tooling to machine the crank throw, a built up design was substuted in the model.. The kit does not include the crankshaft casting, but this casting is available on special order for those who want it.

TIming Gears (Steel) 20 dp 12 tooth 60 deg helix pinion, and 20 dp 24 tooth 30 deg helix gear.

Prints Complete set of AutoCad drawings