1925 175 HP Otto

Coolspring Spotlight: A 1925 175 HP Otto engine on display at the Coolspring Power Museum.

| April/May 2012

This display consists of a 175 HP Otto engine driving a Triplex 3-cylinder Worthington positive displacement water pump. These pieces of equipment have always been mated together and were installed in 1925 in the Brookville, Pa., water works, only 8 miles north of the Coolspring museum.

This engine includes a sideshaft that drives a governor and over and under exhaust and intake valves. The governor acts upon the stroke of the intake valve rocker arm, so it’s a throttling engine; it throttles by limiting the amount that the intake valve opens. It is air-started with a valve in the center of the cylinder head; a combustion air inlet and gas inlet form the mixer, which is where the engine gets its fuel. The exhaust comes out a water-cooled elbow.

The flywheel on the sideshaft is a normal flywheel, but the flywheel on the offside has a very wide rim, which drove a centrifugal pump that pumped water from a nearby creek into the treatment plant.

Read more about this engine and 38 others in the book, Coolspring, published by Gas Engine Magazine. Order it online at Gas Engine Magazine's store. 


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!

Be sure to take advantage of the Square Deal Subscription Program.

  • No Missed Issues.

  • No Renewal Notices.

  • No Additional Cost.

The Square Deal Subscription Program is designed as a paperless transaction with automatic renewals at a preferred low rate.   With advanced electronic notification, a 100% satisfaction guarantee and an easy opt-out plan, the Square Deal Subscription Program is the best value, risk free, eco-friendliest way to subscribe.

Facebook YouTube


Copyright 2018, All Rights Reserved
Ogden Publications, Inc., 1503 SW 42nd St., Topeka, Kansas 66609-1265