HEAVY METAL


| November/December 1986



Fairbanks-Morse Diesel Engine

Fairbanks-Morse diesel type 'Y', style '' two cycle, 80 HP, 300 rpm, weight 14 tons, built 5/16/21. Note: In the foreground is a 1921, 6 HP Fairbanks-Morse used to run the starting air compressor.

Route 4, Box 518 Easley, SC 29640

This article has been prompted by the activity associated, this summer, with two large 80 HP Fairbanks-Morse diesel engines. In early 1970 and 19711 wrote three articles in the GEM on the subject of locating, moving and starting these engines. During the past 15 years of start-ups and running for various groups and individuals these old engines have been given lots of care, but being run just for static display and never under a load, carbon build-up has become quite heavy on the pistons and rings. There had been one piston pin that always knocked quite a bit and one connecting rod bearing had started running hot due to the lack of oil getting to the slinger ring on the crankshaft. The water jacket gasket between the hot head and cylinder head dried out and began to leak. The leather seals in the crankcase air valve had deteriorated and cracked making the engines hard to start. The air start check valve in number one cylinder was not seating because of carbon build-up which caused the loss of compression. The injector pumps were losing their prime between starts making it necessary to reprise the system each time and the injector nozzles dripped after each injection.

Well, with this list of problems I decided to start a major overhaul project. The first thought that came to mind was the overhead rigging and large tools that would be needed for such a project. A set of one inch drive sockets starting at one inch through four inches were acquired and the over head scaffolding was rigged as needed.

Some insight on the history and specifications of these engines might paint a better picture of what is ahead. The engines serial numbers are 632698 and 660568. They were built by Fairbanks-Morse Company in Beloit, Wisconsin and shipped May 16, 1921 and Oct. 25, 1926 to parts unknown. These two engines wound up in the western part of South Carolina to supply power to sawmills and cotton gins some 60 years ago. The old engines are full diesel, type 'Y', style 'VA', two cycle, 80 HP, 300 rpm and weigh about 14 tons each. They have a dry crankcase, therefore all lubrication is done by a Madison Kip lubricator and oil reservoir located under each main bearing. The engine is started by compressed air driving down number one piston and when number two comes up on compression it starts firing.

The first step of this overhaul project was to remove the number one cylinder head with the leaking air start check valves and remove the piston in the same cylinder that had a piston pin knock. The water manifold between the two cylinders was removed first, which weighs 200 pounds, next the hot head was removed after loosening the 1.5 inch hold down nuts. The cylinder head is held in place by 10 studs 1.5 inches in diameter with 2.250 inch nuts. The cylinder head and hot head weigh 305 pounds. The crankcase inspection cover and crankcase air valve was removed to expose the connecting rod and bearing. A come-along was rigged over head on a windlass and chained to the piston by two eye bolts to pull the piston and connection rod from the cylinder. The piston, rings, piston pin and connecting rod weighs 515 pounds. The rod bearing halves are held together about the crankshaft and to the connecting rod by two 1.750 inch diameter and 18.0 inch long studs with 2.250 inch nuts. The rod bearing halves are solid brass with 0.250 inch thick babbitt lining and each half weighs 42 pounds. The oil collector and slinger ring that is attached to the crankshaft and supplies oil to the connecting rod bearing was removed for cleaning. This is a typical tear down of one cylinder, so by multiplying by four cylinders one can see the amount of work to be done.

The next major step on one engine was to remove the fuel reservoir and injector pump housing. The fuel injector pumps and injector nozzle were completely disassembled and all valve seats were lapped and honed with 9 micron diamond paste. The air starting valves that are located in the same housing were removed and their seats were ground and lapped.