The Internet Craftsmanship Museum Presents:

Irwin G. "Irv" Ohlsson

Innovator and model airplane engine builder

Irwin Ohlsson is seen on the cover of a 1968 issue of Model Airplane News with his "Pacemaker" amphibian. Irv's son recalls many weekends at Lake Elsinore watching his dad fly this model. (Click on photo for larger image.)

An early love of airplanes

When Irwin “Irv” Ohlsson was seven years old, he be was already fascinated with airplanes. He would carve them out of solid wood and swing them around his head on a string to watch them fly. In 1927, Charles Lindberg’s flight across the Atlantic inspired not only Irv Ohlsson, but many others to a renewed interest in flight. At age 18, Irv had already built and flown a number of rubber band powered aircraft and had won 11 major contest trophies. One was for a record-setting flight of 1 hour and 3 minutes reaching an altitude of 4300 feet and flying over 30 miles.

In 1932, Maxwell Bassett had set the record for a model airplane powered by a gas engine.* He used an engine built by Bill Brown, Only two years later, Irv Ohlsson took a 30 cc gas engine designed for model boat use and fitted it to an airplane model of his own design. It had an 8-foot wingspan, weighed 10 pounds and swung a 20” propeller. He put the model in his 1928 Ford and drove to a contest in Sacramento. There were three other entries, all powered by Brown Jr. engines and his with the modified boat engine. Two of the airplanes crashed. Dr. J. P. Young got his to fly for 26 minutes. When Irv’s turn came, his stayed aloft for an hour and 6 minutes—a record that stood for many years. A pilot in an airplane flying nearby reported sighting Irv’s plane at 5500 feet in altitude.

*Graham Knight in Shepperton, England informs us that the first known recorded gas engine flight was made by D. Stanger of England with a record of 51 seconds in 1914. This record stood for 18 years until beaten by Colonel Bowden in 1932 with a flight of 71 seconds. Later in 1932, Maxwell Basset topped that time and held the record that Irv Ohlsson and others were shooting at in 1934. As you can see, the technology of model flight took some big steps between 1932 and 1934. It took 18 years to add 20 seconds to the record, but in two years the flight times went from just over a minute to more than an hour.

Newspaper contest spurs development of a small new engine

In 1934, The Los Angeles Herald Examiner was looking for a small model aircraft they could use as an incentive for their delivery boys to boost circulation. Having gained a name for himself with his record-setting flights, Irv Ohlsson was asked to build the first prototype. To keep costs down, it was to be powered by a compressed-air engine that burned a solid fuel stick to produce the gas to drive the 5-cylinder radial powerplant. It flew well but the heat generated would often cause the airplane to catch fire after landing, so the project was abandoned. Later, however, he had an idea of how to build a gas powered engine that would be small enough for the project. Working with friend Roland Barney, in about two months they had produced two very small engines with a 1/2” bore and 5/8” stroke, resulting in a .12 cubic inch displacement. These were smaller than the model engines then being produced on the East coast at the time, and a test at Muroc Dry Lake (now Edwards Air Force Base) early one morning showed that they could work. By this time, however, there was a different editor at the newspaper and the model incentive project had been abandoned, but Irv Ohlsson was on his way to a career in designing model airplane engines.

(As a note of interest on that first prototype, Irv lost track of it after selling the two engines. About fifty years later, he got a call from Erwin Schwartz who said that Victor Savage had installed one of the engines on a high-wing monoplane back in the 1930’s. He also said he had one of the engines and would return it to Irv. Several weeks later, he received the very first Ohlsson engine. This is a piece of history that he was very gratified to have back, and it is still in the possession of his son, Irwin “Gus” Ohlsson Jr.)

From a hobby to a business

After graduation, Irv went to work for Douglas Aircraft. His first love was model flying, however, and he soon left Douglas to open a model shop of his own in Los Angeles. He had come up with a good design for an engine and wanted to go into production. He contacted machinist friend Harry Rice and got a quote for the tooling for the first run of his new engines. The cost would be $2600, which was a lot of money at the time. Irv borrowed $1300 from his mother from his dad’s insurance money and got friend Frank Bertelli to borrow $1300 from his parents to finance the first run of engines. They assembled and test ran each engine in their shop. This engine sold for $16.50, which was about a week’s pay for the average worker at the time. Many boys now recall saving their every penny for a long time to buy that engine for their model airplane. The Ohlsson Mini was known as the “Gold Seal” and had a displacement of .56 cubic inches, forged rods, a 1-piece head and cylinder to prevent leakage and produced about 5 pounds of thrust with a 14” prop at 7000 RPM.

Irv also designed and sold several airplane kits. His first was in 1934 and was called the “Speedmark”. He combined it with a Brown Jr. engine. The five-foot wingspan model kit sold for $15.00 and the engine added another $18.00 to the price. If you bought both together, the price was $25.00, which was a lot of money in the 1930’s. In 1937 he came up with the “Pacemaker” design. This was a good looking and sturdy aircraft that was well suited to engines at the time and many were built. The kit and engine again sold for $25.00

Ohlsson and Rice company formed

By 1941 Irv Ohlsson had teamed up with Harry Rice, and the firm of Ohlsson & Rice were producing a “.19”, a “.23” and a “.60” that were highly popular. No other engines at the time combined the reliability, ease of maintenance, simplicity of operation and unlimited life of the O & R engines. The Second World War put a temporary hold on their success, however, as all manufacturing facilities were turned over to military production. By the time the war shut down their production, they had produced about 75,000 engines.

As soon as the war was over, O & R got back into production. Even with a shortage of needed materials and machines somewhat worn out by 3-shift a day wartime production use, they jumped back into a market that had a seemingly endless demand for their products. Modelers were hungry to get back into flying, and O & R took advantage of the market by buying the machinery needed to meet the huge demand. By the end of 1947 their production had risen to almost a thousand engines per working day.

When glow plug engines started to become popular in 1947, O & R were ready with their own designs. One of the problems with glow engines was the availability of the proper fuel, so they began manufacturing their own brand of fuel for both glow and ignition engines. They also started making propellers, metal-bodied model racecars and a series of O & R glow plugs.

In 1949 they released their new “29”, which was basically a slightly reworked “23”, but it met with huge success. They quickly followed it with the “Redhead 33”. At this point they were at the pinnacle of their career with the largest and wealthiest company in the hobby industry.

Rushing so many new products to market at once, however, had some serious ill effects on the quality of the engines. The new designs started to show some flaws that caused many engines to be returned to the factory for repair. Problems with the die-cast aluminum rod distorting and bending caused them to be replaced by forged steel rods. This, however, pointed out another problem with the engine when the stronger rods transferred stress to cylinder case base, causing the engines to fly apart when running on glow fuel. The high number of returned engines caused financial stress that eventually led to the breakup of the partnership of Ohlsson and Rice, but not before they had produced well over a half million engines.

A change of direction keeps the Ohlsson name in the model aircraft market to this day

Irv Ohlsson soon got back into business when he purchased the old “Spitfire” company facilities including their large fuel packaging plant. He began producing his own line of fuel and glow plugs. He also packaged fuels for several other well-known model engine manufacturers under their own names. Irv died a few years ago, but his son, Irwin “Gus” Ohlsson Jr. continues to operate that business today. Irv Ohlsson is often credited with being one of the major contributors to the hobby of model aircraft flying. Ohlsson engines were a large factor in the early growth of the sport of model airplane flying.

Here are several photos of Irv Ohlsson and his engines:

(Click photo for larger image.)

The original two engines Irv designed and built for the newspaper promotion in 1934 were sold shortly thereafter. Irv was overjoyed when one of the original prototypes was returned to him nearly fifty years later.
A second view of the original prototype from 1934, which is now owned by Irv's son, Irwin "Gus" Ohlsson, Jr. At the time it was designed, it was the smallest gas model engine in the world at .12 cubic inches of displacement. (1/2" bore x 5/8" stroke)
Irwin Ohlsson launches his “Pacemaker” at the old Rosecrans and Western field. It is powered by an early “Gold Seal” engine (Photo: Dick Tichenor)
Irv’s first production engine, the #5 original Miniature .56 cubic inch engine
A photo from late 1936 shows Irv Ohlsson with Sam Kramer in front of the shop at 650 N. Alvarado Street in Los Angeles. The airplane shown was built for Sam by Irv and Frank Bertelli for a total cost of $45.00. Using the #1 engine shown in the photo, Sam put 1000 flights on this airplane.
Cover of Model Airplane News from June, 1968 shows Irv Ohlsson with a Pacemaker amphibian. It was taken in front of the K&B plant in Downey where Irv’s good friend Dan Lutz worked at the time . Irv’s son Gus Ohlsson recalls many days flying this plane with his dad at Lake Elsinore.
Another plane built by Irv Ohlsson was shown on the cover of the March, 1993 RC Modeler magazine. This modified Widgeon weighed 20 lbs and was clocked at 85 MPH! Irv would have expert flier Joe Bridi fly it because it was such a rocket, but in Joe’s hands it could do 8-point rolls and fly inverted. Irv’s son still owns this aircraft.
This Ohlsson .23 was purchased in 1947 by Carl Hammons who was later to become Joe Martin's business partner for many years. Their love of model airplane flying is what brought them together, and this engine was Carl's first. Engine on display at the Craftsmanship Museum in Carlsbad, CA.

Varo Amp-Champ 12 VDC Field Generator

The Varo Amp-Champ was powered by an Ohlson & Rice 2-cycle, single cylinder model airplane engine (Type 122) that was rated at 3/4 HP at 6300 RPM. It ran on 70-80 octane pump gas mixed with oil at a 24:1 ratio. Joe Martin donated this engine, which was used in the field for starting model airplanes in place of a battery. We are also told that they were used during WWII and the Korean war as portable auxiliary power generators to run field radios for communication on the battlefield. Lighter than a large 12 Volt battery, they would also produce power as long as you had a source of gasoline for fuel.

This is a good example of turning lemons into lemonade when the wartime market reduces demand for a hobby product like a model airplane engine.  In typical government fashion, complete instructions for starting and running are printed on a decal on the engine so any soldier could get it running. Plug gap, points gap and magneto gap were all right there as were mixture and starting procedures. Although O&R engines were no doubt chosen for their famous reliability, it was noted in the instructions, "Clean cylinder exhaust ports when engine loses power."

This generator is on display in the Craftsmanship Museum in Carlsbad, CA

Ohlsson "Pacemaker" 1937 California State Freeflight Champion

The "Pacemaker" that won the 1937 California Freeflight Championship was patterned after a similar version Irv built to compete in the 1934 National Championships. This model is either the original converted for use with radio control and covered with a new skin of monokote to replace the original doped silk covering or a second version built to honor that plane. The fact that it is powered by a K&B .40 may indicate that it predates the Ohlsson & Rice production engines that Irv built later in the 1940's and 1950's. This plane was donated by Joe Bridi, who often acted as Ohlsson's "test pilot" due to his skill in flying model aircraft.

Wingspan=68", Fuselage and engine length=48". On display at the Craftsmanship Museum in Carlsbad, CA.


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