Tuesday, March 22, 2016

1916 7 HP Economy Gas Engine Project



Since last March, 2015, 19th century Willowbrook Village has been offering classes in Antique Engine Repair and Maintenance. In the Fall, our class worked on a 1918 seven horsepower Model E Economy engine. The Economy had long been part of a static exhibit in the museum's Engine Shed. The fly wheels of the Economy had at one time been switched so that the flat belt pulley was located on the right side to receive a belt that was connected to an 1885 all cast iron construction Chase shingle mill. The static exhibit is inaccurate, as the 7 horsepower, although powerful, would not have provided enough power to effectively cut shingles from log sections. It is likely that the horsepower required would more likely be in the 15-20 horsepower range.

 https://youtu.be/nYUmh6-O-tU






Like many of the gas engines in the collection, this had been purchased in the late 1960s or early 1970s nad had simply been sandblasted and painted. The red paint had been generously applied, so much so that parts of the engine were rendered immovable. One area in particular, the push rod, required much scraping in order to free springs in the assembly. In a follow up class we will replace the push rod return spring as it no longer serves its purpose. Paint penetrated into the cylinder head. In the Fall class we removed the head and cylinder. One of the three rings on the cylinder head was discovered to be broken. After a rebuild on the magneto, replacement of the ignitor gasket, removal of the gas tank and the temporary replacement of the tank with a portable tank our instructor Doug Kimball brought with him, we hoped to start the engine. 

The Economy engine was long paired with an 1885 Chase shingle mill; the flywheels were actually switched to achieved the right side flat belt pulley arrangement. This engine did not have enough horsepower to actually run the mill.

 The engine had been lifted by a portable aluminum Gantry crane we assembled in the space. A chain fall allowed us access to the underside of the engine where the gas tank was located. The skid was removed for the purpose of removing the tank, and it was. The tank was badly corroded and filled with sediment. The skid was very lightweight for this engine that weighs more than a thousand pounds. The skid ran the width of the cast metal base containing the hollow where the gas tank resides. This skid had to be replaced; a skid of greater width would serve to make the engine more stable and less prone to tipping over. 



The engine was returned to the skid once the tank was removed; the skid and tank would replaced by the time our next class was scheduled, and we would purchase the other necessary parts to get the engine running with the assistance of a whole new set of students on March 19th and 20th in our next Antique Engine Repair and Maintenance class.  in the mean time, we attempted to switch the remaining rings around so that the two original and unbroken rings were seated at the top and middle of the piston head. in place We re-inserted the piston into the cylinder with the two rings and returned the cylinder head with a new head gasket in the hope of starting the engine. 

Instructor Doug Kimball with the Economy's piston removed.
Pulling on these very big flywheels to start it proved futile. There was not only little compression but the fuel intake gasket we had replaced leaked like a sieve. The engine subsequently would sit for several months in the engine shed until our next class. By that time, a new custom made gas tank with a formal soldered copper pipe air intake instead of a more primitive puncture at the top of the tank would be ordered and delivered from John Wanat & Sons of East Redding, CT.. Like many early gas engines the gas tank is hidden within the cast metal base to the engine. Two brackets surround the tank and attach it within. The skid that this particular engine was attached  to was a bit light for the more than 1000 pounds of the engine. As the skid was also constructed solely of two 2 x 6s running from front to back and attached by the four anchors.
 
Removing the piston

In the interim the engine was moved from the engine shed to our new Machine Shop. A new oak skid was created and the needed parts were had. The work on March 19 & 20 included raising the engine with the help of the Gantry crane again. The new gas tank was fitted using the original brackets. The engine was anchored to new skid and lowered to the floor where the head and piston were once again removed. The new 5 3/4" x 3/8" piston rings were installed. The head was returned and fastened. The ignitor gasket was renewed



We tried to start the engine. After many tries we decided to wait until the next day. it was determined that the spark was good, but that the engine was not getting gas. The previously cleaned and lubed gasoline check valve was examined and found in good condition. What we had assumed to be a compression fitting was found to be a second check valve rusted shut. The second check valve was removed which allowed the fuel to flow.

After only a few tries the engine started. We allowed the engine to run for some time allowing the rings to seat which was illustrated by the gradually improved performance of the engine. Another issue was revealed. The head gasket had blown out on one side. The head and the remains of the gasket were removed again. Upon closer examination of the surface of the head high and low spots were identified. A straight edge was used for this determination. A flat file dressed the head preparing it for our next work date when we will renew the head gasket, install a new push rod return spring and install the missing outer baffle plate on the muffler which will be cast in one of our casting classes.



 Economy engines were first made in Sparta, Michigan, by the Holm Machine and Manufacturing Company. for Sears, Roebuck & Co. By 1912, demand had predicated the creation of the Hercules Gas Engine Company to keep up with demand. The Hercules Company purchased Holm and a new factory in Evansville, Indiana soon resulted. The first Hercules produced engines were sold in January 1914 and were known as the Model D. The Economy engine produced for Sears differed slightly in design to the Hercules, having a more rounded lip to the water hopper and  no crank guard. The two engines were further distinguished by the color red for the Economy and green for the Hercules brand.

The Model E, our project engine model,  was popular. There were more than 220,000 engines sold of this type. Our Model E dates from 1918. The Model E was followed by the "F", which was produced from 1921 to 1923. An estimated 25,000 Model Fs were produced. There were design modifications from the "E" including the use of Webster 1A and 2C magnetos. These magnetos proved unpopular, and many were replaced by either Wico EK high-tension magnetos or the older Webster oscillating magneto.

 

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