Gas Engine Restoration and the Missing Piston

Don’t let missing pieces keep you from a great gas engine restoration

| October/November 2011

I did some gas engine restoration work for a fellow engine collector in 2008. When I delivered the engines, he had a 1-1/2 HP contract engine built by Rock Island Plow Co./Alamo Engine Co. (as they were in business together in 1916). It has a skeleton-cast frame, 11-1/4-inch pulley cast into the power side flywheel and a 3-inch pulley on the magneto side. I’m guessing it was built on contract and sold to a jobber or special order because  the brass tag offers horsepower and serial number but no additional information.

The 11-1/4-inch pulley has two bosses cast into the inside radius of it with brass bushings and oiling spots. This, and the fact that it had a Webster magneto, were good. The bad news was that there was no piston or connecting rod, and it had a very rusty cylinder bore and a bad fuel tank. Also, the igniter was missing the anvil arm, cam and roller. All in all, though, it wasn’t that bad. A deal was struck and I went home with a new project.

Fixing the igniter 

I started by restoring the igniter. I had to make a new cam and roller assemble-advance-retard- lever with the flat spring, then make a new anvil arm for the Webster magneto igniter. This went well. I had a very good spark so all I did to the magneto was oil it; sometimes it’s best not to touch something good!

Working on the head

The round loop boss for the pushrod on the engine head was broken and had been brazed before and broken again. To fix this, I made a jig fixture that aligned the round pushrod to the head, sawed off the broken cast iron part that was brazed and electric welded with nickel rod a new round boss that was a little thicker and stronger than the original. This had to be preheated and post-cooled to keep the cast from cracking. The welding jig held the new guide in place and alignment was good.

The engine valves were good, but the springs and valve retainers needed to be replaced, so I made new retainers.

Repairing the governor

The fuel elbow mixer just needed cleaning and a new brass seat for the mixture screw, as it was all torn up from over tightening when shutting the engine off. The cam gear shaft was worn out, and the oil hole in the block with a Gitts Oil Cup on it was plugged with hard oil and dirt, so I made a new shaft and cleaned the oil passage. I took off all of the speed governor parts and cleaned and oiled them as well. I also made new pivot pins for the flywheel weights.