I’ve worked on several car and motorcycle engines throughout my life. While it’s not work I particularly enjoy, I do enjoy seeing the inner workings of an engine firsthand and thinking of what must have gone into their design. If you’re interested in having a better, first-hand understanding of how an engine works and how it’s put together, then read further so you can build your own mini engine kit. Keep in mind that these are simplified models, and do not 100% accurately represent everything that goes into an engine. Kits to build real, functioning engines are beyond the scope of this article.
Inexpensive Options
I’ve split this post up into two categories: inexpensive and expensive models. This section is for the more inexpensive options.
These kits have parts on sprue. You’ll need fine-grit sandpaper and/or a sharp knife to clean off the sprue left behind after you remove a piece. To remove the piece itself, I recommend using flush cutters. Twisting or breaking off the part by hand can damage it, especially if it’s small and delicate. When a model has moving parts and you don’t clean the sprue off, the best case scenario is that your model will undergo unnecessary wear over time. Worst case scenario is that something will snag and break.
Trends UK Haynes V8 Engine

Build your own mini engine kit with the Trends UK Haynes V8 Engine. This kit is a motorized model of a dual overhead cam V8 engine. The box has everything needed for assembly, except for 3 AA batteries, which you’ll need to power the motor. It includes over 100 parts making this a somewhat involved model, most of the parts being plastic with a few metal pieces. You assemble the motor with either metal screws or by snapping or press fitting the plastic pieces together.
The motor included with the engine turns the crankshaft, making everything else move in turn, and causes the spark plugs to flash, simulating a real engine when it’s running. Turning on the motor produces ignition and engines sounds. The instruction manual is clearly written and straightforward with clear, black and white pictures of each process. At the end of the manual is a section describing how a real engine works with a note on general engine upkeep and fuel-efficient driving. There is also a glossary of basic engine terms at the end of the manual.
The instruction manual is clearly written and straightforward with clear, black and white pictures of each process. At the end of the manual is a section describing how a real engine works with a note on general engine upkeep and fuel-efficient driving. There is also a glossary of basic engine terms at the end of the manual.
Summary
- Plastic model of a dual overhead cam V8 engine
- Includes over 100 parts (over 200 when including pieces such as screws)
- The kit includes everything needed for assembly
- Includes motor to turn crankshaft to simulate the movement of a real engine
- Motor makes ignition and engine sounds
- 3 AA batters are required to run the motor and produce the sounds, but are not included
Trends UK Haynes Jet Engine

The Trends UK Haynes Jet Engine is a plastic model of a two-spool jet engine. (Two-spool essentially means that there are two shafts in the engine, one for the high-pressure compressor and turbine, and one for the low-pressure compressor and turbine. The manual contains more information). An electric motor powers the engine. so you can see how it works once it’s built.
The box includes everything to assemble the kit, except for 3 AA batteries for the motor and jet engine sounds. Most of the parts are plastic, and the rest are either rubber or metal. You assemble the kit with either screws or by snapping or pressing the parts together. The kit isn’t modeled after any specific, real jet engine. It’s a simplified version of a generic jet engine to help illustrate the main components of a two-spool jet engine and to show how one works. The manual is clearly written with clear, black and white pictures, and it includes a brief section explaining how jet engines work.
Summary
- Plastic model of a generic two-spool jet engine
- The box includes everything to build this miniature engine kit
- Includes motor to simulate the motion of a real jet engine
- Makes jet engine sounds when turned on
- 3 AA batters are required to run the motor and produce the sounds, but are not included
Revell ¼ Visible V8 Engine

Here’s another V8 engine to choose from. This one is a bit different from the Trends UK engine in that it is more detailed and has more clear parts to make the inner workings of the model more visible. Specifically, the engine block, cylinder heads, and valve covers are all clear. Overall, this kit is more advanced than the Trends UK kit. You assemble the model with glue and metal screws, so in addition to what the box includes, you’ll also need glue—a screwdriver is included. The glue I recommend and have used exclusively for years is Testors 3509C Plastic Cement.
The manual is clearly written with French and Spanish translations of the English instructions, where required—the majority of the process is conveyed through pictures. The manual recommends cooking oil for lightly lubricating certain parts. You operate the model with a hand crank on the front of the engine once you’ve assembled the model. This crank directly connects to the crankshaft, so as you turn it, everything else in the engine operates as well. Personally, I prefer this over the motorized option because it doesn’t require batteries and it’s quieter. The variable speed inherent in a hand crank also means that you can turn the engine as slowly as you want, slowly observing the individual reactions between all the components.
Summary
- A plastic V8 engine model with clear engine block, cylinder heads, and valve covers
- Build this miniature engine kit with glue and screws (screwdriver included; does NOT include glue)
- Operate the engine using a hand crank on the front of the engine
- No batteries required
Trends UK Porsche 911 Flat-Six Boxer Engine

The Trends UK Porsche 911 Flat-Six Boxer Engine is a 1:4 scale model of Porsche 911’s flat-six engine. This engine kit also has a clear casing so you can see the engine’s internal workings. Like the other Trends UK models, it also has a motor to turn the engine. As the engine “starts” and runs, a speaker produces engine sounds and LEDs simulate the spark plugs firing.
Many model engine kits focus on the V8 (there are already two such kits in this list) so I find this flat-six to be refreshing. You assemble the model using only screws. The manual, like the manuals for the other Haynes models listed here, is easy to follow and includes a section about the real-life version of the model and another section describing how an engine works. The box has everything in it that you’ll need to build the miniature engine kit, though you’ll need to supply 3 AA batteries for the motor.
Summary
- Model of the Porsche 911 Flat-Six Boxer Engine with clear casing
- Assembled with screws
- A motor turns the engine and a speaker produces engine sounds
- Everything needed to assemble to kit is in the box
- Motor requires 3 AA batteries (not included)
Trends UK Haynes V-Twin Motorcycle Engine

The Trends UK V-Twin Motorcycle engine is a model of a V-twin engine, an engine type found in a wide variety of motorcycles. This engine is also motorized with flashing spark plugs, so when you turn the motor on, the crankshaft turns, operating everything else in the engine, and as the engine runs, the LEDs in the spark plugs flash and a speaker produces engines sounds. You need three AA batteries to run the motor, but the kit doesn’t include them, though it includes everything else. You build this mini engine kit with screws and a few snap-together and press-fit parts.
The manual, as with the other Trends UK products, is easy to follow and includes a section on how an engine works, some information about the real-life version of this specific engine, and a glossary of terms. The inner workings of this model are not as visible as those of the others on this list. The cylinders are transparent, so you can see the pistons moving, but not much else on the model is transparent, so it’ll be hard to see the motion of the crankshaft. Other than that, the model is a good choice for an absolute beginner because it’s relatively simple compared to the V8 models.
Summary
- Plastic model of a V-Twin motorcycle engine
- Includes a motor to turn the crankshaft and operate the engine
- As the engine runs, the LEDs in the spark plugs flash and a speaker produces engine sounds
- The kit includes everything needed for assembly
- The kit does not come with the 3 AA batteries required to run the motor
Some Higher-End Options
As the previous section was about cheaper options to build your own mini engine kit, this section is for the higher-end options.
The following three models are from Engine DIY. They’re pricier than the previous models (a few hundred dollars), but they’re definitely prettier and have a very nice, full-metal construction. Like many of the cheaper engine models listed above, these use an electric motor to power their movement, so they still aren’t true engines in the sense that they run on fuel and utilize the four-stroke cycle. To get an overall idea of the assembly process and how these model engine kits look and work, check out this video of the Single-Cylinder Engine Build Kit.
Each of these miniature engine models comes with the tools necessary for assembly (Allen wrenches of varying sizes), but there are a few other things you should have on hand. These aren’t strictly required for assembly, but are recommended by Engine DIY: a fine metal file or fine sandpaper for light adjustment in case parts don’t fit together perfectly, and some light oil. Make sure the file/sandpaper is indeed fine because some of the parts in these kits are aluminum, and aluminum is a relatively soft metal. You don’t want to create large gouges in the model because you used a rough file or filed improperly. The oil will help with wear and tear since this kit involves moving metal parts. Though the kits don’t include oil, the manuals will tell you where to apply it. Each of these models is recommended for everyone ten years and older.
Single-Cylinder Engine Build Kit

The Singe-Cylinder Engine Build Kit is the simplest of the metal engine model kit I’ll be listing. It consists of 130 aluminum alloy and stainless steel pieces with a couple of rubber belts and a 500mAh lithium polymer, rechargeable battery to power the motor, which turns the crankshaft. The battery has a charging time of about 40 minutes and can run for over 30 minutes (battery charger included). The engine model is the smallest of the three listed here at 117mm*86mm*200mm. It weighs 3.5kg and takes about 3.5 hours to assemble. Engine DIY rates the assembly difficulty at 3 / 5 stars. The kit comes very nicely packaged in a metal box. To make the inner workings of the engine more visible despite the metal body, the engine model includes cutaways in the cylinder and the crankcase, and the cylinder head, flywheel, and various other systems are left exposed.
Summary
- Metal model of a single-cylinder engine
- Includes a 500mAh, rechargeable, lithium polymer battery with charger
- Battery takes 40 minutes to charge to full and can run over 30 minutes
- Includes 130 aluminum alloy and stainless steel parts, plus rubber belts and the necessary assembly tools
- Difficult: 3 / 5 stars
- Size: 117mm*86mm*200mm
- Recommended to have on hand a fine file or fine sandpaper and light oil
V-Twin Engine Build Kit

The V-Twin Engine Build Kit is a metal engine kit for a generic V-Twin airplane engine including a propeller that spins as the engine operates. Like the Single-Cylinder Engine Build Kit, the crankcase and cylinders have cutaways to enable you to view the engine’s inner workings, and it leaves the cylinder heads and other systems exposed. This model is a bit more complex than the previous one at 217 aluminum alloy and stainless steel parts (except for the plastic propeller and the rubber belts). It’s also slightly larger, at 213mm*215mm*135mm and 3.5kg. The power system is the same, with an electric motor turning the crankshaft powered with a 500mAh rechargeable, lithium polymer battery. The assembly difficulty is rated at 4 / 5 stars and the model takes about three and a half hours to complete. Check out this video to see the full assembly process:
Summary
- Metal model of a V-Twin airplane engine
- Includes a 500mAh, rechargeable, lithium polymer battery with charger
- Battery takes 40 minutes to charge to full and can run over 30 minutes
- Includes 217 aluminum alloy and stainless steel parts, plus rubber belts and the necessary assembly tools
- Difficulty: 4 / 5 stars
- Size: 213mm*215mm*135mm
- Recommended to have on hand a fine file or fine sandpaper and light oil
4-Cylinder Car Engine Build Kit

Of the three mini engine models listed here, this is the largest and most challenging at a difficulty rating of 4.5 / 5 stars, measuring 182mm*150mm*120mm, and weighing about 4kg. It contains 357 aluminum alloy and stainless pieces plus the rubber belts. As with the other models, this one uses an electric motor powered, but with a larger, 700mAh rechargeable, lithium polymer battery to turn the crankshaft. As always, the crankcase and cylinders have cutaways to view the internal workings of the engine, and the engine’s external systems are left exposed. Watch this video to see the engine running and to see the assembly process. You can also check out the manual. Keep in mind that this is a Chinese manufacturer, so the English translation of the manual has some odd wording, but I didn’t find it difficult to understand.
Summary
- Metal model of an inline four-cylinder car engine
- Includes a 700mAh, rechargeable, lithium polymer battery with charger
- Battery takes 40 minutes to charge to full and can run over 30 minutes
- Includes 537 aluminum alloy and stainless steel parts, plus rubber belts and a plastic propeller, and the necessary assembly tools
- Difficulty: 4.5 / 5 stars
- Size: 182mm*150mm*120mm
- Recommended to have on hand a fine file or fine sandpaper and light oil