The Seal Engine Project
Building a Seal 15cc Internal Combustion Engine
A Group Project With Parts Made by Model Engineers Around the World
The project featured on this page was built over the course of a year in the Craftsmanship Museum machine shop. Many of the parts for this engine were built by different craftsmen from around the world, and then assembled in the Craftsmanship Museum. We have documented the build on this page, and recognized the craftsmen who contributed. Many photos and descriptions of the process have been provided as a teaching experience.
Starting the Seal Engine Project
The Joe Martin Foundation began the construction of a 15 cc, 4-cylinder internal combustion engine in July, 2006. The goal was to make this running Seal engine for eventual display as part of the Craftsmanship Museum’s collection in Carlsbad, CA. We started out with a casting kit and a set of plans, and began to enlist the help of others.
Tom Boyer ran the museum shop, and acted as both machinist and job coordinator for the project. We invited model engineers from around the world to participate in the museum shop project. A list of those craftsmen, along with their contributions can be found below (*check).
- Designer: Edgar T. Westbury (designed in 1947)
Type: 4-cycle, water cooled, inline 4-cylinder
Size: 6.75″ L x 4.75″ W x 5.25″ H
Displacement: .84 cu. in. (13.8 cc)
- Carburetor: M&H Variable Venturi (modified)
Ignition: ProSpark electronic with Hall sensors and rare earth magnets, Rimfire long reach spark plugs
Fuel: white gas
Started: July 25, 2006
First Run: July 21, 2007
The Build Team
View a list of the build team members for the Seal engine project, along with some of the components built by each craftsman.
Additionally, view a copy of our build team plaque, produced by Craig Libuse.
Model Engineer Articles on the Seal Engine
Model Engineer magazine in England published a 13-part article by Edgar T. Westbury (the engine designer) on the Seal engine—starting with the February 9, 1947 issue. Because of copyright issues, we cannot republish those articles here. However, the Craftsmanship Museum now owns a complete collection of Model Engineer magazine issues going back to the first publication in 1898. In our library, visitors have access to these issues, and are allowed to copy a portion of any issue for their own personal use.
We do not have a complete article index, but visitors are free to browse through our extensive collection. It’s often the case that the plans published in Model Engineer are actually more complete than the original plans. Additionally, the comments from the builder can very helpful in finding and fixing problem areas before you get to them. For example, we learned from the Westbury article that the firing order for the Seal as published in the plans was actually incorrect.
Full Seal Engine Build
View our chronological documentation of the full Seal engine build, including many more photos and video of the running Seal engine.