Cox model engines

Cox model engines are used to power small model airplanes, model cars and model boats. Cox engines were in production for more than 50 years between 1945 and 2006. The business gets its name from Leroy (Roy) M Cox, the founder.

Roy Cox started L.M. Cox Manufacturing Co. Inc. who later became "Cox Hobbies Inc." and then "Cox Products" before being sold to Estes Industries when it became Cox Models.

Leroy Cox developed an early interest in mechanical devices while working around his father's bicycle shop in Placentia, CA. Once out of school he spent 20 years as an electrician, running his own electrical business part time. Efforts to branch out into a photography equipment business were unsuccessful due to shortages of materials caused by World War II.

In 1944, he came up with a superior design for a wooden popgun and produced it on a small budget it his garage with the help of neighborhood women as his workforce on an initial investment of USD 2200. Like some of his later products, its success was based on the fact that it was better built than the existing competition. Sales took off rapidly and the product was a success; however, the renewed availability of metal for toys at the end of the war meant that wooden toys were soon to be a thing of the past. Cox recognized this and along with a friend, Mark Mier came up with a design for a metal model racecar to take advantage of post-war America's fascination with cars. By August 6, 1946 he and a crew of 20 people were turning out 1500 unpowered model cars a day.

A fire that totally destroyed the factory on August 7th brought an end to production after 4 months. The destruction was almost total and there was no insurance, but they still had orders on hand, so he did some fast talking and bought a nearby vacant lot. A military-type Quonset hut was set up in 4 days, and by October 15th he was back in business filling orders for Christmas. He even managed to double his production capacity with the emergency change.

He introduced the Cox Thimble Drome Champion racecar in 1947. This model was not a pull toy but included a handle and cord that attached to the side so it could be swung around in circles at high speeds. The 9-1/2' long metal car had rubber tires and an attractive paint job, adding to its success. The USD 4.95 car ushered in the start of the popular fad of tether car racing and the 'Thimble Drome' name was soon to be applied to future products as well.

Cox noticed that customers, fascinated with the realism of the Champion racecar were installing engines from model aircraft in it. He contracted with Cameron Brothers model engine company for a .25 cubic inch engine that could be installed in the Champion using a direct drive. The confined cockpit area dictated vertical cooling fins rather than horizontal as was the convention. A later engine called the 'Doodle-Bug' was similar but smaller with a displacement of .099 cubic inches, and a larger .19 engine was also developed. By 1948 he was ready to introduce a ground-breaking engine powered racecar. It was the first under USD 100, at only USD 19.95. Sales that year were over USD 500,000 for cars with and without engines. He also developed and sold his own brand of Thimble Drome racing fuel.

On February 7, 2009 Estes Industries stopped producing Cox engines and sold all of their remaining inventory i.e. mainly spare parts, to several private buyers from Canada and USA. One of the new owners of the remaining Cox engine and parts inventory has launched a website, Cox International with online store.

Millions of engines were produced and they became the most common 1/2A Class 0.049 cubic inch engine in the world and probably still are today.

Updated: 29 October 2020

Cox Model Engine value and price guide

What's your Cox Model Engine worth in 2021? Here are some recently sold items.

Item Title Date Price
ronald valentine rasant v twin 098 x 4 cylinder diesel Ronald Valentine Rasant V Twin 098 X 4 Cylinder Diesel 06/2021 $2 728.00
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no pictureSee all sold items on eBay for more prices10/2021$-.--

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