Free Flight: Old Timers
By Clarence Haught
Cottage industries: Where would old-time model aviation be today if not for the dozens of private individuals who have taken it upon themselves to produce supplies, materials, kits, plans and even engines? From personal observation most of these enterprises are a labor of love; few provide the entrepreneur with a living. For this reason I like to bring new products to the attention of Old Timer modelers through this column.
Simplex Miniature Engines (John Morrill)
Address: 143 Richmond Street, El Segundo, CA 90245
Some time ago I reported on the activities of model enthusiast John Morrill, founder of Simplex Miniature Engines. John initially built six Simplex .25 engines based on the Louis Garami design (Strato-Streak), published in Model Airplane News in 1947. These early engines were test-flown in a Ranger and a Cloudster and would turn a 10-3/4" Top Flite prop at about 7,000 rpm. Encouraged but not satisfied, John set out to improve performance while retaining the original style and spirit.
John summarized his intentions: "Redesign was undertaken mainly to increase power, yet still retain the style and flavor of the original. The intention was not to produce a hot engine but rather an engine with adequate power output for Old Timer flying, keeping within the spirit of the movement."
Main changes made in the redesign:
- Altered port timing and increased various port openings to improve breathing and power.
- Eliminated the conrod-piston ball-and-socket joint for simpler, more robust construction.
- Replaced the blind-bore cylinder with a separate cylinder head.
- Added a separate phosphor-bronze main bearing instead of running the crankshaft directly in the front plate material.
- Redesigned the timer/front plate for better performance.
Production and performance:
- John decided on a production run of 50 engines; production drawings were completed over two months.
- The run of 50 was finished prior to the 1979 SAM Champs in Salt Lake City, where John displayed engines and parts at the MECA Collector event the day before the contest.
- The new engine will swing a 10-3/4" Top Flite prop at just under 10,000 rpm — a significant increase over the initial version.
- The SAM engine committee approved the engine for official SAM competition, making it an approved Class B engine.
Workmanship and availability:
- The engines are machined from good materials with an emphasis on precision and finish. This all-machined construction requires considerable extra work.
- Future production runs may use some cast parts to reduce machining time; if you want one of the all-machined versions, contact John immediately.
Publications from Art Suhr
Address: W218 N5866 Maclynn Ct., Menomonee Falls, WI 53051
Art Suhr is another dedicated modeler and collector who has compiled and reproduced a wealth of material on old engines and model aviation for quick reference. He has produced several handy volumes and reprints, often as labors of love rather than commercial ventures.
Earlier works include:
- Antique Gas Model Engines — 68 pages of early advertisements and pictures (valuable quick reference).
- Model Motors of 1940 — reprint of the 1940 Hurleman catalog.
- 1940 GHQ Catalog — reprint.
- An Advance in Model Flying — reprint on the H&H glow engine.
- Model Engine Reviews — reprints of engine articles from Flying Aces, Air Trails, etc.
- Model Magazine Index and Inventory Sheet.
Recently released titles:
- The 1935 Brown Jr. instruction book — includes prop-carving instructions, parts list, and reproduction box top and labels.
- The 1940 Bunch Catalog — a 40-page reproduction (originally sold for 20 cents in 1940) printed in an attractive blue-and-white format; includes full-size drawings of the entire 1940 line, specifications and construction features.
- Glow Plug Model Engines 1950–65 — an 85-page book featuring many illustrations of popular engines, many full size.
Notes:
- The Brown Jr. book includes prop-carving instructions — not many modelers carve gas-model props nowadays.
- The Glow Plug Model Engines book should sell well given current interest in nostalgia events; even those who prefer gas engines will find it a trip down memory lane.
- Art is considering additional projects, such as a book on "Miniature Race Cars and Racing Engines" and a collection of original engine direction sheets. If you’re interested, let Art know — a little encouragement may get these projects done.
Odds 'N' Ends
One of the pleasures of attending national contests is meeting legendary modelers. Irwin Ohlsson visited the 1979 SAM Champs in Salt Lake City, and many contestants enjoyed hearing his stories about the "good old days." I asked him about the total number of engines he produced — his estimate was "about a million." Even more surprising was the production breakdown: approximately 800,000 O & R .23 engines were made. That leaves about 200,000 for all other models combined (.19s, .60s, .29s, .33s, Gold Seals and Miniatures).
Also of interest: Mark Fechner, who specializes in repair and service of O & R engines, is planning to produce a batch of the first Ohlsson engine. More on that later.
Clarence Haught Rt. 5, Box 16, Coeur d'Alene, ID 83814
Transcribed from original scans by AI. Minor OCR errors may remain.
