Simanaitis Says

On cars, old, new and future; science & technology; vintage airplanes, computer flight simulation of them; Sherlockiana; our English language; travel; and other stuff


INTERNAL COMBUSTION engines built before 1900 are celebrated as “centennial engines.” And, among enthusiasts of things mechanical, the Coolspring Power Museum is a real treasure trove of these wonderful devices.

Twice yearly, Coolspring has a special Expo. The “Gas” of this Gas Engine Show in 1999 was hydrogen, chosen for its similarity to “town gas” of the centennial era.

Coolspring is a tiny farming community about 80 miles northeast of Pittsburgh, Pennsylvania, just off Interstate 80.

Punxsutawney Phil may not know it, but he resides only 10 miles from what’s likely to be the world’s largest collection of operating centennial engines.

There’s logic in this location: Unused barns and sheds gave hobbyists John Wilcox and Paul Harvey a place to store—and tinker with—the old engines they collected. One thing led to another, and today Coolspring Power Museum displays 250 engines in 20 buildings, hosts two major shows each year, in June and October, and has been named a Mechanical Engineering Heritage Collection by the American Society of Mechanical Engineers. Visit its website at to learn about its (rather limited) open hours, special events and the like.

This artful device, an Otto & Langen atmospheric engine, circa 1867, is on display at the Coolspring Power Museum.

The earliest Otto & Langen was an atmospheric engine, ambient air pressure providing the power stroke. Its cylinder’s combustion chamber received an uncompressed bit of internal combustion; as it cooled, a partial vacuum was generated within. This caused ambient pressure of the air to push its piston upward on the engine’s power stroke. A rack and pinion translated the piston’s motion to the flywheel.

Centennial engines are artful in their construction, often displaying elements of pure design such as the Otto & Langen’s fluted column. Other beauty lies in their exposed hardware offering a perfect lesson in the intricacies of Nikolaus August Otto’s four strokes.

Like many of these stationary engines, this one has a horizontal layout. The cylinder head is closest in view; the single-throw crankshaft and its sizable flywheel are farthest.

More than one scheme was tried to initiate combustion. My favorite is flame ignition, wherein a sliding plate carries flammable gas past a pilot light, then exposes it to a port in the cylinder head. All this occurs with barely audible pops, as compression ratios are modest, barely 3:1, amid much gentle clinking, clanking and whirs.

Flame ignition, centennial style.

The elegance of flame ignition: At left, pocket h in sliding plate C receives its charge of flammable gas from port k. The gas is ignited by pilot light l. Simultaneously, cylinder port b gets its fresh gas-air mixture through g and f aligning with pocket e. Then, at right, pocket h and its flaming gas aligns with port b, thus (one hopes) igniting the cylinder’s gas-air mixture.

These stationary centennial engines originally operated on “town gas,” the same stuff used for illumination during the Gaslight Era. In a wonderful blend of the past and the future, Coolspring Power Museum is set up to fuel its centennial engines on the nearest modern equivalent—hydrogen. ds


  1. Bill Urban
    September 25, 2012

    After growing up with go-karts and 2-stroke chainsaw engines, this always stuck with me. Years ago I read of very early stationary, low RPM, two cycle engines that had no mechanical means of pumping intake air. They had extremely long intake tubes that accomplished cylinder charging solely by sound wave tuning. (No memory of their taking advantage of the “waves” on the exhaust side.) Perhaps Coolspring has an example.

    For enthusiasts it will come as no surprise that I later owned a Dodge, 383 V8 with . . . “ram induction”. And for those not familiar, the carburetor for each cylinder bank was positioned beyond the opposite bank valve cover, the longer intake runners tuned, in this case, for additional torque. Who remembers those humongous engine bays?

    • simanaitissays
      September 27, 2012

      Remember when it was possible to drop a wrench underhood and it would actually hit the ground? No longer.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.


This entry was posted on September 25, 2012 by in Just Trippin', Sci-Tech and tagged , , .
%d bloggers like this: