Oldest Otto 4-Stroke Engine in the World

A limited opportunity to view a historically significant engine in its temporary home in Pennsylvania.

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courtesy of The Henry Ford
The lay shaft and governor side of engine No. 1355.

Take this limited opportunity to view this Otto 4-stroke engine, the oldest operating engine in the world, now on display at the Coolspring Power Museum.

Amongst the great ones, Crossley Brothers Engine No. 1355 is one of the most historically significant 4-stroke cycle engines in the world. It boasts an incomparable pedigree among 4-stroke cycle engines and is now on public display for the first time in decades.

The story starts with the world’s first successful IC engines built in the late 1860s by Gasmotoren Fabrik Deutz in Cologne, Germany, and Crossley Brothers in Manchester, England. These early Otto Langen non-compression atmospheric engines made a huge statement by showing the world economical and easy starting options compared to the complexity and hazards of steam power. Although physically limited to a maximum of 3hp, these early pre-4-stroke cycle machines were noisy and mechanically cumbersome, but production reached about 5,000 engines by 1877.

Inherent shortcomings led to exhaustive development into the next generation of internal combustion. Created in the Cologne, Germany, factory, Nicholaus Otto’s newer 4-stroke engine was revealed to the world in late 1876, and it went on to become the most successful and influential engine ever designed.

The Otto 4-Stroke Engine

Otto’s new 4-stroke engine was patented in every industrialized country. Although, the main focus of the claims was not 4-stroke operation. Rather, his patent was to protect a supposed stratified or laminar flow of air and gas into the combustion cylinder during the intake stroke. Interestingly, he did simultaneously design and test this new engine in both non-compression and 4-stroke cycle configurations. Each version had problems in its introductory layout. The non-compression design was prone to great stress from shock loading as the hydrogen enriched fuel combusted mid-stroke; and the ignition of the 4-stroke cycle concept engine was simply unreliable. Even with the problematic introductory design of the 4-stroke version, Otto had demonstrated to his head engineers, Wilhelm Maybach and Gottlieb Daimler, the incredible significance and potential of this new engine.

The non-compression version was quickly abandoned, and the flame ignition porting was perfected and incorporated into the 4-stroke cycle version. In an interesting collaborative effort between Otto and their English licensee, Crossley Brothers, a simple but effective improvement allowed an accurate and repeatable transfer of the ignition flame from the slide valve into the combustion chamber of the test engine. Working at great speed, with the genius of Maybach, Gasmotoren Fabrik Deutz introduced a line of engines based on this prototype that could be manufactured with the space and technological limitation of their pre-existing Otto & Langen factory. Otto ambitiously built a couple of early pre-production engines and showed them at various expositions around Europe. Word circulated rapidly that this new engine would revolutionize small- to medium-sized applications in the industry. Their design was shared with Crossley in England, and both companies built a handful in 1876 and a couple hundred total by the end of 1877.

The earliest few 4-stroke engines were built with some inherent shortcomings and likely had to be reworked or replaced over time with improved designs. In less than a year, the initial difficulties had been resolved. Of all the engines built by Deutz, Crossley, and other royalty paying companies, The Henry Ford THF Crossley serial number 1355 is the oldest surviving production 4-stroke in the world. A crown jewel of their enormous technological collection, it is identified in their accession records as 3-1/2hp, the 56th 4-stroke cycle built by Crossley Brothers in their Manchester, England, works with a ship date of Sept 30, 1877.

Virtually every part on this engine is unique when compared to other existing Crossley slide valve era engines.  There are telltale marks and holes of some earlier parts that were likely upgraded in the early years of its life. A quick study reveals a dozen or so unique features. A couple of the most obvious are:

  1. The engine has no counterbalance weight on either the crankshaft or flywheel — all other Crossley slide valve era engines have some means of accomplishing this.
  2. The slide valve (wear) surface on the head is not made as a replaceable plate.

Other characteristics found on only the earliest few Crossley Brothers engines are square wire slide valve cover springs, large over-sized cast-bronze slide valve cover wing nuts, cylindrical-shaped belt-drive oilers, and saucer shaped governor hood.

From The Henry Ford to Coolspring Power Museum

Back in the 1920s, when Henry Ford had plans of building a private world class educational and technology facility, scouts were sent all over the world with unlimited money and instructions to fulfill his dream. In the case of early prime movers and stationary engines, a friend and facility manager of a Ford automobile factory in England was chosen to lead this task on the European front. His name was H.F. Morton, and he frequented many of the great collections and museums in an attempt to assemble an unprecedented collection of historic technology. Early records still remain showing, that of all the hundreds of objects Morton searched for, a specific group of early internal combustion engines were on Henry Ford’s wish list. By 1928, most of these items were procured, including SN 1355, which was given the designation of asset No. 28.102.5. A select group of significant and early slide-valve internal combustion engines were restored by machine shop employees at Ford’s Rouge (Detroit) facility. Rebuilt to like new, these engines were set up in his museum and started on special occasion. This astounding collection of technology was known at the time as the Edison Institute. Once word got out of its significance, the public begged to see the collection. A few years later, it opened to the public and was eventually known as The Henry Ford.

With changes in THF focus and public interest, SN 1355 was ultimately removed from the museum’s display floor in the late 1990s and placed in indefinite storage, where it would rest with the remaining 95% of Ford’s mechanical and technological collection. Long time members of the Coolspring Power Museum remembered seeing this great historic engine on visits to THF and in a special effort, made the financial investment to borrow it and display this in their Preston Foster/Susong building. It took a year of planning with insurance companies, THF staff members, shipping companies, Coolspring, and a team of volunteers to make this a reality. On a beautiful sunny day in early October 2020, the engine was relocated from Dearborn, Michigan, to its new (temporary) home. For those appreciating early internal combustion engine history, it would be prudent to make time to see this significant exhibit while it is at CPM. The author wishes to pass along the fact that THF made it clear that once the Crossley SN 1355 is returned to Detroit, it likely will not be put on public display again. Enthusiasts are encouraged to take advantage of the CPM display of this machine before it heads home.


Wayne Grenning is a regular contributor to Gas Engine Magazine and can be reached at wgrenning@gmail.com.

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