Restoration of a Smith-Langmaid Marine Engine

| October/November 1990

  • Marine engine before restoration
    Smith-Langmaid marine engine before restoration
  • Marine engine after restoration
    Smith-Langmaid marine engine after restoration

  • Marine engine before restoration
  • Marine engine after restoration

75 Kendall Avenue, Framingham, MA 01701.

I acquired an old Smith-Langmaid marine engine in June 1988 after it had been an ornament in a stone wall for more than 20 years.

Fortunately an opening in the engine once occupied by an ignitor had been covered by a small metal plate, but when I attempted to turn the heavy flywheel it became obvious that the piston was frozen to the cylinder wall.

After trying several methods recommended for freeing frozen pistons without any result, the use of a welder's torch was successful and the piston came loose. The piston, connecting rod, two bearings, and the crankshaft were then removed from the engine's main frame.

The cylinder wall was smoothed with a honing tool powered by an electric drill, and after the piston rings had been removed, their grooves were cleaned.

After reinstalling the rings, the piston and connecting rod were reinstalled with some difficulty. The crankshaft and bearings were reinstalled, but a good mechanic would have replaced the bearings at this time. However, the engine was now back together again and the piston was operational.