A Brief Word

| March/April 1999

Air Pump


34/3/5 Fairbanks-Morse Q. I am restoring a Fairbanks-Morse 1? HP engine, s/n 440684. On the water jacket I found the casting number 21820. Since the s/n references a date of early 1920, can I assume that the casting number is translated to February 18, 1920? Also on the left crank journal cap I have found stamped the number 3 RIV.7 What does this pertain to? Any information would be appreciated. Gary Everett, Overland Park, KS 66204.

A. It was (and probably still is) a common practice to date castings at the foundry. In many instances at least, the castings were set outside to 'cure' for a few weeks or a few months. This helped the castings stabilize so that when they were machined they would 'stay put' and not twist or warp. We don't know the meaning of the 3RIV figure on the bearing cap.

34/3/6 Pouring Bearings Q. Being a new subscriber, I have seen references to pouring babbitt bearings, but do not know where to look. Can you refer me to the proper issues? W. P. Haworth, PO Box 358, Clifton, CO 81520.

A. We have had some short descriptions of the process in this column, notably in the July 1991 issue. In our September/October 1983 issue, we had a two page article with illustrations of the process by Donald Goldsby. In our December 1998 issue, there was an article on page 10 which described the services of a shop in West Virginia which provides this service.

34/3/7 Milwaukee Compressor Q. See the photo of an air pump made by Milwaukee Air Power Pump Co., Milwaukee , Wisconsin. What was the original intended purpose of this pump, and how was it lubricated? Any information on this unit would be greatly appreciated. Dean Suhr, 3525 E. Hawser St., Tucson, AZ 85739-8898.

A. This is simply an air compressor, and it might have been used for any number of reasons. Years ago, air compressors were usually found in service garages, and some shallow well systems used a jet arrangement whereby compressed air was used to push water to the surface. Aside from these purposes, air compressors weren't widely used except by industry. Some early compressors had an opening in the side of the cylinder that was filled with wicking. This served to provide a small amount of lubricant to the piston. We would guess that this one got an occasional shot of oil from an oilcan. Air compressor pistons are lubricated very sparingly.