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Field Notes

Making New Valve Springs

new valve springs new valve springs new valve springs

Faced with replacing two broken valve springs on an ancient 4-cylinder engine, I found springs of the correct diameter and correct wire size. The stock spring was longer and stronger, so I gambled on some homegrown metallurgy. The replacement springs were fully compressed with bolts and washers, then cooked in a gas grill on the highest flame for three hours with the cover closed, then allowed to slowly cool in the grill. The resulting springs had a reduced spring rate of 40lb/in, matching the original spring, and matching height. Poor man’s metallurgy!

Leon Ridenour

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Single-Cylinder Beilfuss Automobile Engine

Single-Cylinder Beilfuss Automobile Engine

David Pfaff, who works with the non-profit R.E. Olds Transportation Museum in Lansing, Michigan, sent in some photos and information about the The Beilfuss Motor Co., Lansing, Michigan, which made a number of interesting engines, including horizontal singles and opposed twins. David writes:

The Beilfuss Motor Co., organized by Richard A.F. Beilfuss, was incorporated on June 4, 1902, with capitalization of $15,000. It was located at the corner of Saginaw Street and the Michigan Central Railroad (701 East Saginaw) in Lansing, Michigan. MotorWay reported in 1902 that Beilfuss would build gasoline engines for automobiles, in addition to the stationary type. Their initial offering was a single-cylinder, horizontal unit that developed 8 hp at 750rpm for automotive application, with a weight of 350 pounds. It featured a sideshaft valve train, gear-driven from the end of the crankshaft. The intake valve was of the atmospheric style.

Single-Cylinder Beilfuss Automobile Engine

Their stationary engine, a vertical design, was reportedly made in 2 hp to 7 hp outputs. In 1905, Beilfuss announced the availability of a new 16 hp, 2-cylinder, opposed-style automobile engine with a weight of 300 pounds. It featured a 5-inch bore and stroke. A 1908 advertisement in Gas Power featured a 2-cylinder opposed stationary engine producing 13-15 hp with a weight of 560 pounds, touted for stationary, portable, electric and general use. A notice in PowerBoating promoted the Beilfuss marine engine.

In 1910, Beilfuss advertised their 2-cylinder automobile engine, either air cooled with 10-12 hp or water cooled with a choice of 10-12 hp or 18-20 hp. The Beilfuss automobile engine was promoted as an original equipment unit for builders of “assembled” automobiles and as a replacement for worn-out engines in existing autos. The company was in business through 1912.

A single-cylinder Beilfuss automobile engine was recently donated to The R.E. Olds Transportation Museum. This engine is from the automotive collection of Don and Ken McDowell, well-known collectors of all things automotive, especially Lansing related. The engine was mounted in their 1899 Oldsmobile electric when they acquired it 1959, the sole survivor of R.E. Olds’ early foray into battery-powered vehicles. An early attempt had been made to convert it from battery to gasoline power. The conversion was never completed, and the vehicle has recently been converted back to its original electrical configuration and is currently on display in the museum.

The engine has been cosmetically restored and mounted on a display stand along with the planetary transmission that was found with the engine. The engine turns over readily, and perhaps has never been run. The exhaust valve train is missing. The intake is atmospheric. Our thanks go to Ken McDowell for his generous donation of this rare piece of Lansing industrial history along with his continuing loan of the 1899 Oldsmobile.

David Pfaff
R.E. Olds Transportation Museum
240 Museum Dr.
Lansing, MI 48933

Please send your questions and comments for Flywheel Forum to Gas Engine Magazine, 1503 SW 42nd St., Topeka, KS 66609-1265 or email

Scale Gas Engines and Conveyer


Reader M. Moyers writes in, sending photos of some of his scale gas engines and a conveyor he built to make loading and unloading them for shows easier. We think the conveyor is a neat trick, and love the cam-stopper Callahan. “The flyballs disengage the camshaft when the engine is up to speed. The camshaft is timed to stop with the exhaust open. It’s a good runner,” Moyer writes. 
As to the conveyor, he says, “I built the conveyor to make it easier to load and unload engines. I don’t need to get into the truck with each engine; the engines are the last to go on the display and the first to be removed when the show is over.”


M. Moyers
37301 28th Ave. So., Unit 31
Federal Way, WA 92003

Please send your questions and comments for Flywheel Forum to Gas Engine Magazine, 1503 SW 42nd St., Topeka, KS 66609-1265 or email

Thread Standards Concerns


Restorers of old engines and machinery inevitably run into problems involving thread or fastener standards, the most common being the 1/2-12 UNC standard that appears to have been used before World War I. I have not seen this standard on anything built after about 1918, when it changed to 1/2-13 UNC. In the British Whitworth threads, the 1/2-12 BSW continued until Whitworth was effectively abandoned in favor of metric in the early 1970s. Yet even standard sizes can vary slightly, which leads me to assume that many early manufacturers made their own taps and dies and didn’t always adhere to national standards. In addition to thread standards being “loose,” I have come across nuts or bolt heads with unusual hex sizes, sometimes made to the nearest 1/32 inch.

A frustrating thread-related problem recently occurred restoring a 4 hp Excelsior engine, where I found that all the tapered pipe threads used on the fuel tank, fuel pump, mixer and return circuit were oversized. The threads on a modern fitting bottomed out before they mated up. Clearly, Excelsior made their own taps and chose to make them about 1/32 inch oversized!

To overcome this, I purchased a taper turning attachment for my Hardinge lathe in order to custom make the oversized tapered pipe fittings. This attachment has since come in very handy for producing British Standard Pipe threads. Anyone owning or contemplating owning an English engine will find the common use of BSP threads. In every case the Whitworth thread angle is 55 degrees and in almost every case there is a different number of threads per inch. The basic pipe size and taper are the same, which means you cannot visually tell the difference between NPT and BSP. Don’t make the mistake of thinking a few extra turns of Teflon tape will fix the problem!

NPT and BSP are the only two tapered pipe thread standards in the world. Modern machinery uses one of the two, and you might be surprised to know that machinery (CNC lathes, milling machines, etc.) made in Taiwan or Japan is quite likely to have BSP threads used on the various hydraulic components.

I have experienced some real disasters that occurred at the port of entry where accessories are added before shipment to the end customer. Unfortunately, there is no color coding or distinguishable marks to alert technicians to the lack of interchangeability, and the inevitable happens. I never cease to be surprised at the number of “experienced” engineers and technicians who believe there is a metric pipe thread system or that BSP is metric: neither is true.

Perhaps the most shocking aspect of lack of standardization occurs in the metric thread system. While metric threads don’t show up often in engine restoration, they are out there. I came across two instances of standardization lapses recently. The first showed up when I tapped a metric M-10 x 1.0 hole in a model engine to accept an NGK CM-6 spark plug. The plug was so loose I dared not get it more than finger tight. When I measured the pitch diameter of the threads I discovered that they were 0.006-0.008 inch (0.2mm) undersized.

More recently, I made an adapter to install a modern NGK glow plug into an early Ruston & Hornsby open-crank diesel engine. The published size of the glow plug was M-10 x 1.25 and I ran into the almost identical problem after tapping with an ISO standard tap; the plug fit so loose I couldn’t risk using it. Again, the threads checked out at 0.008 inch (0.2mm) undersized. I sent an email to NGK outlining this problem, but have not received a response.

Having been an engineer and a journeyman machinist for over 60 years (I trained at Rolls Royce’s aircraft engine pision) I have certainly seen my share of peculiar thread problems. Many younger engineers are convinced the metric system is the ultimate in standardization, but as an “old timer” I know that the Whitworth thread standards (no longer used) and the American Unified screw thread systems are the two most standardized in the world, and this results in absolute interchangeability within their respective systems, something that does not happen with metric threads.

Please send your questions and comments for Flywheel Forum to Gas Engine Magazine, 1503 SW 42nd St., Topeka, KS 66609-1265 or email

More Tiny Tim Generator Information

Tiny Tim

J.D. Schmidt sent photos published in the October/November 2017 issue of a Tiny Tim 12-volt, 300-watt generator powered by a 1/2 hp 4-stroke engine, asking if readers knew more about the units. We noted that small generators like the Tiny Tim were inspired by efforts to supply like-type units for military use, prompting the following note from reader Ken Karrow, who writes: 

“I believe they were developed and sold to charge batteries for the home owner as opposed to a military application. I have one with a Montgomery Ward tag on it that says Wards Airline. It is a 6-volt unit with battery ignition. As an ex-Wards employee, I know that Airline was Ward’s trade name for their home entertainment items. This would include radios back in the day when REA had not reached lots of homes yet, so this would have been sold with a radio to a customer who did not have electricity yet. 

“Lots of radios in this time period were 6- or 12-volt, and the amp draw was too high to use dry cells. The expense of dry cells would be prohibitive, so wet cells were used and needed to be recharged. I have two more of these that I have not got to working with yet. Neither have tags so I don’t know the voltage. One is a Tiny Tim look-alike and the other is a Pincor. All three of mine are electric start, and I suspect the one in the photos is, as well. There is a button directly under the handle that looks like an old dimmer switch button. I suspect that will energize the generator as a starter and they switch to a generator when up to speed. I have tried the Wards unit on a run-down 6-volt battery and it will crank slowly and start. The pulley is an ordinary V-belt pulley with a notch in it so you can rope start, but on mine you still need a battery with at least a little charge to operate the ignition. You can also use the belt pulley to operate anything that uses only about 1/2 hp with the battery fully charged. If the battery is low, it won't have enough power to operate something else and charge the battery as well.

“I know this is getting long, but I will relate a story that my dad tells about my grandfather. When Dad was young they had a radio on a battery, but Grandpa was too cheap to buy a charger. He would park his Chevrolet on a hill in the yard and my dad had to remove the battery and hook it to the radio and when grandpa was ready to go to town, Dad had to take the battery back out and install it in the car. I believe that it was a 1918 Chevrolet. Then Grandpa would let the car roll down the hill, engage the clutch, start the car and go to town and do his business. When he got back the battery was charged up and he would repeat the process.”

Please send your questions and comments for Flywheel Forum to Gas Engine Magazine, 1503 SW 42nd St., Topeka, KS 66609-1265 or email

Sandwich Engine from the Archives


Thumbing through the GEM archives, we  found this photograph of engine enthusiast Elwin Cunningham tending to his 6 hp Sandwich engine at a June 1977 gathering at the Museum of Transportation in Owls Head, Maine.

The photograph was taken by Elwin’s friend, Charles Chiarchiaro, and includes the note, “Ran all day, never missing a beat.” It was subsequently published in the September/October 1978 issue of GEM, along with a short story by Charles about his friend. At age 19 Elwin, who was born in 1913, was working for the Diamond Match Co., first tending boilers and then operating two Ames Uniflow engines. He went on to work for the Central Maine Power Co.

One of the founders of the Maine Antique Power Assoc., Elwin had a collection of over 40 engines, including a 15 hp IHC Mogul sideshaft, a 15 hp IHC Famous, a 15 hp Fairbanks-Morse, and of course the 6 hp Sandwich. You can read Elwin’s story at

Please send your questions and comments for Flywheel Forum to Gas Engine Magazine, 1503 SW 42nd St., Topeka, KS 66609-1265 or email 

Leader Iron Works Engine and Pump Unit

Leader Iron Works.

Months ago, reader Eugene Cook sent in a photocopy picture of his Leader Iron Works 4 hp engine and pump unit, along with a brief note. We lost track of Eugene’s letter and are just now running it, with an enhanced version of his photocopy. Our apologies, Eugene! 

Eugene writes: “It has been in our family since the mid-1930s when my father used it to pump water for our dairy cows from a hand-dug water source in the pasture during summer drought periods. With the help of my mechanic friend ‘Scottie’ the unit was put back in operation several years ago and mounted on an antique display wagon that Scottie found. The water barrel has been replaced with a large antique cast iron kettle we used on the farm to heat water when butchering pigs before World War II.

Eugene Cook

Please send your questions and comments for Flywheel Forum toGas Engine Magazine, 1503 SW 42nd St., Topeka, KS 66609-1265 or email