5 Of The Best Antique Mini Engine Kits You Can Buy | SlashGear & EngineDIY

BY JOE CAPRARO/OCT. 20, 2023 7:45 AM EST

Retro tech is back in style, from classically styled motorcycles like the Janus Halcyon 450 and Kawasaki W800 to Atari's re-release of "Save Mary," which was a game discontinued in 1990.

Holiday gift-giving season is also approaching quickly, and one gift that will bring a smile to the face of any scientifically inclined teenager or retro-tech-obsessed adult in your life is an antique engine kit. EngineDIY offers a wide variety of functional antique engine kits, from engines designed for model planes and boats to early steam engine replicas and fully operational models of nearly 100-year-old motorcycle engines.

The kits highlighted here all use real combustible fuels, so none of them are intended for young children. But for an older child with an interest in vehicle history or how internal combustion engines work or an adult with steampunk leanings, any one of these five kits could make a perfect holiday gift.

MUSA Red Dog model engine

One engine kit with practical use possibilities is the MUSA Red Dog single-cylinder engine kit, which can be used to power model airplanes and boats. This air-cooled, gasoline-powered engine retails for $499.99 and is based on the 1940s-era Kittiwake engine.

The kit's components are mostly aluminum alloy, brass, and steel, and the engine runs on gasoline or kerosene and requires 5W-20 or 5W-30 4T oil for lubrication. The kit does not come with a spark plug, base, or ignition system and must be started with a pull starter or power drill. The single cylinder has a displacement of 7 cubic centimeters, and the engine has a power output of about .5 PS, equivalent to a little less than one-half of one horsepower. The engine can run between 1,800 and 6,000 rpm, and while the only two buyers who left reviews gave the kit five stars, they noted that some adjustments were necessary to get the engine to run properly.

Retrol V-twin motorcycle engine

For motorcycle enthusiasts, an appropriate choice is this Retrol V-Twin motorcycle engine kit, which sells for $899.99. This kit is a 1/5 scale model of the Harley-Davidson Knucklehead motorcycle engine that was introduced in 1936. This engine kit is made of brass and stainless steel and comes with a flat wooden base for mounting.

The four-stroke gas-powered engine includes an adjustable carburetor, and each cylinder has a bore of 13 millimeters and stroke of 16 millimeters, making the engine's total displacement 4.2 cubic centimeters. The engine takes a 1/4-32 Thread ME8 Spark Plug and requires a pre-mixed 25/1 fuel/oil blend to run properly.

It can be started with a power drill or the included pull start cord, and the spark is provided by three AA batteries, which are not included in the kit.

Both buyers who provided reviews gave the kit five out of five stars. Mark from St. Louis called it a "fantastic little machine" and wrote, "The engine is a functional work of art, and I can't wait to run it! It is a beautiful addition to my small but growing collection of these mini-engines."

H08 Hoglet


Similar to the Retrol V-twin motorcycle engine is the H08 Hoglet Engine kit, which sells for $649.99. This kit is also a four-stroke V-twin engine modeled after Harley-Davidson motors from about 100 years ago. This motor has similar dimensions to the previous kit but starts using a kick-start lever instead of a drill or pull-start cord. It is made of aluminum alloy, brass, and stainless steel and comes with a 150-millimeter x 120-millimeter x 30-millimeter wooden base.

Users must supply the three AA batteries necessary to provide a spark for ignition, as well as 95-octane gasoline and engine oil.

Seb from Bochum, Delaware, gave the kit five stars and wrote, "Engine is well made. Easy to start, and it works very well. Like all mini V2 engines, you unfortunately can not reach very low idle because of too little weight at the crankshaft/flywheel."

AKR46 from Tosu, Japan, gave the kit four stars and had some additional tips for prospective buyers, writing, "In order for the engine to run smoothly, it is necessary to pour sufficient oil into the moving parts. When the engine was difficult to start, I cleaned the inside of the carburetor, and it started working."

R18 flywheel engine

For the automotive historian in your life, consider the R18 one-cylinder flywheel engine kit, which retails for $459.99. This engine is a replica of the three-wheeled Benz Patent Moterwagen I, the first motorized car to hit the roads in 1886.

This kit is made of brass and is powered by 95-octane gasoline and three AA batteries, which are not included in the kit. The engine can be started by manually spinning the 10-centimeter flywheel, either with a pull cord or a rubber wheel attached to a power drill.

All four buyers who left reviews gave this engine kit five stars, although Günter Krusek did have some issues with air leaks that he was able to remedy with larger O-rings and a bit of silicone sealant.

Henry Bangsberg from Chicago called this kit "a beautiful recreation of a historic piece of engine development," and Harold from Berlin, Delaware, wrote, "A great engine, very detailed replica of the Carl Benz engine. A beautiful collector's item."

H75 Tractor Engine

One of the most complex and expensive antique engine kits for sale at Engine DIY's website is the H75 12cc Tractor engine kit, which sells for $1,499.99. The engine itself is made of brass and stainless steel and sits on a 250-millimeter x 120-millimeter x 30-millimeter bamboo base. The engine is fueled by 95-octane gasoline, and the ignition system requires three AA batteries, which are not included in the kit. You can start the engine with a power drill or by manually spinning the flywheel, and the engine's speed can be varied via a throttle lever on the side of the motor.

Despite the high price of this kit, some buyers reported problems with fluids leaking from or inside the engine. Lucas Bilovsky from Brno in the Czech Republic wrote, "The mechanical design of the engine is very nice. The engine runs very well right out of the box. However, it has a problem with oil leaking from the crankcase."

Andre Häfeli — who did not give his location — reported a different fluid leak issue, writing, "It's a cool engine, but I had a problem with the cylinder leaking water into the engine."