Yes, we are here!

In times like these our hobbies become lifesavers. At GAS ENGINE MAGAZINE and FARM COLLECTOR, we have been tracking down the most interesting and rare vintage farm machines and collections for more than 80 years combined! That includes researching and sourcing the best books on collectibles available anywhere. Our online store is open and we are here to answer any questions you might have. Our customer service staff is available Monday through Friday from 8a.m.-5p.m. CDT. We can be reached at 1-800-888-9098 or by email. Stay safe!

Coolspring Power Museum Features Rare Engine

300 HP Miller, manufactured by the Miller Improved Gas Engine Co., on display at the Coolspring Power Museum.

| August/September 2013

  • Model 3 Open at Coolspring Power Museum
    The Model 3 Open, produced by the Miller Improved Gas Engine Co., Spingfield, Ohio. 
    Photo By Christian Williams

  • Model 3 Open at Coolspring Power Museum

Manufacturer: Miller Improved Gas Engine Co., Springfield, OH
Year: 1913
Serial Number: 1326
HP: 300
Bore: 17-inch
Stroke: 22-inch
Weight: 70,000 lb.
Ignition: Dual spark plug with magneto and battery & coil
Governing: Throttle

This engine is known as a Model 3 Open, which is descriptive of its size and layout. It features a quad-opposed style in the “H” design with one center flywheel. There is a center crankshaft with two cylinders extending forward and two cylinders extending aft, all working on a common crankshaft producing the 4-cylinder effect. “To our knowledge it is the only Miller of this design to have survived, and perhaps the only quad-opposed from any manufacturer to be running in this country,” Paul Harvey says.

There is a cam box located on each end of the engine between the two cylinders. The intake valves are horizontal to the cylinder heads and the exhaust valves are vertical, operated by a pushrod that comes up out of the cam box at an angle and pushes a roller against a ramp, which produces movement that causes the valve stem to rise. “The engine’s equipped with Watts-type balanced exhaust valves, meaning that the force needed to open the valve is constant whether the engine is under light load or full load,” Clark Colby says. “That’s accomplished by having the valve stem pass down through the combustion chamber and seating on the top of the mushroom head of the valve rather than underneath like you would expect.”

Read more about this engine and 38 others in “Coolspring,” published by Gas Engine Magazine. 

Contact the Coolspring Power Museum at PO Box 19, Coolspring, PA 15730 • (814) 649-6883 • Coolspring Power Museum website 


Gas Engine Magazine A_M 16Gas Engine Magazine is your best source for tractor and stationary gas engine information.  Subscribe and connect with more than 23,000 other gas engine collectors and build your knowledge, share your passion and search for parts, in the publication written by and for gas engine enthusiasts! Gas Engine Magazine brings you: restoration stories, company histories, and technical advice. Plus our Flywheel Forum column helps answer your engine inquiries!

Facebook YouTube


click me