carburetor

7 Articles

3D Printed Engine Gets Carburetor

August 30, 2023 by 14 Comments

3D printed materials have come a long way in the last decade or so as printers have become more and more mainstream. Printers can use all kinds of different plastics with varying physical characteristics, and there are even printers now for other materials like concrete and metal. But even staying within the realm of the plastic printer can do a lot of jobs you might not expect. [Camden Bowen] recently 3D printed a single-piston engine which nearly worked, and is back with some improvements to it thanks to a small carburetor.

The carburetor itself isn’t 3D printed (although not from lack of trying) — it’s on loan from a weed eater, and is helping to solve a problem with the fuel-air mixture of his original design. Switching from butane to a liquid fuel also solved some problems as well, and using starter fluid also helped to kick off the ignition. Although it ran for a short period of time over several starts, the valve train suffered some damage with the exhaust valves melting in place to the head. This is actually a problem common to any internal combustion engine like this, especially if the fuel-air mixture is too lean, there’s incomplete combustion, the valves aren’t adjusted properly, or any number of other problems. In this case it seems to have been caused by improper engine timing.

It’s actually noteworthy though that the intake valves weren’t burned, meaning that if the engine can be tuned to allow for complete combustion before the exhaust gasses leave the combustion chamber, the plastic 3D printed head and valve train will likely survive much longer operational periods. We’ll certainly look forward to the next iteration of this engine build to see if that’s the case. If 3D printed piston engines aren’t your speed, though, take a look at this jet engine which uses a 3D printed compressor.

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Lawn Mower Carburetor Improves Mileage On Old Sedan

May 16, 2022 by 71 Comments

Before the Ford marketing department started slapping Maverick badges on pickup trucks, the name had been attached to compact cars from the 70s instead. These were cheap even by Ford standards, and were built as a desperate attempt to keep up with Japanese imports that were typically higher quality and more efficient than most American cars at the time. Some people called them the poor man’s Mustang. While Ford and the other American car companies struggled to stay relevant during the gas crisis, it turns out that they could have simply slapped a lawn mower carburetor on their old Mavericks to dramatically improve fuel efficiency.

The old Maverick used a 5 L carbureted V8 engine, which is not exactly the pinnacle of efficiency even by 1970s standards. But [ThunderHead289] figured out that with some clever modifications to the carburetor, he could squeeze out some more efficiency. By using a much smaller carburetor, specifically one from a lawn mower, and 3D printing an adapter for it, he was able to increase the fuel efficiency to over 40 mpg (which is higher than even the modern Mavericks) while still achieving a top speed of 75 mph.

While it’s not the fastest car on the block with this modification, it’s still drives well enough to get around. One thing to watch out for if you try this on your own classic car is that some engines use fuel as a sort of coolant for certain engine parts, which can result in certain problems like burned valves. And, if you don’t have a lawnmower around from which to borrow a carb, take a look at this build which 3D prints one from scratch instead.

Thanks to [Jack] for the tip!

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3D Printing A Carburetor Is Easier Than You Probably Think

May 11, 2022 by 27 Comments

We’ve all been there. You see a cool gadget on the Internet to 3D print and you can’t wait to fire up the old printer. Then you realize it will take 8 different prints over a span of 60 hours, chemical post-processing, drilling, exotic hardware, and paint to get the final result. [Peter Holderith’s] carburetor design, however, looks super easy.

If you have experience with real-world carbs, you might wonder how that would work, but as [Peter] points out, carburetors are very simple at the core — nothing more than a venturi. All the extra pieces you think of are for special cases and not necessary for basic operation. We doubt, though, that you could really use the thing in its current form in your car. There are no mounts and since he printed it in PLA, it seems like a hot engine would be a bad idea. However, it does work well with water and an electric blower.

[Peter] mentions that with some more work and the right material, he has no doubt he could create a working practical carb. We think he’s right. But even in this form, it is a great educational project for a budding car enthusiast — like the old transparent V8 engine models, maybe.

Speaking of transparent, we’ve seen — or maybe not seen is a better phrase — a see-through carburetor that is also a good demonstrator. If you could perfect a 3D printed carb, it would make conversion projects a lot easier.

Car Hacker Hacks Lawn Care Carb Into Hot Rod Car

April 21, 2022 by 45 Comments

Internal combustion engines have often been described (quite correctly) as air pumps, and because of this nature, they tend to respond very well to more air. Why? Because more air means more fuel, and more fuel means more power- the very nature of hot rodding itself. [Thunderhead289] is an accomplished car hacker, and he’s decided to take things the opposite direction: Less air, less fuel… more mileage? As you can see in the video below the break, [Thunderhead289] has figured out how to mount a single barrel carburetor from a lawn mower to the four barrel intake of a Ford 302– a V8 engine that’s many times larger than the largest single cylinder lawnmower!

The hacks start not just with the concept, but with getting the carburetor installed. Rather than being a downdraft carburetor, the new unit is a side draft, with the float bowl below the carb’s venturi. To mount it, a 3d printed adapter was made, which was no small feat on its own. [Thunderhead289] had to get quite creative and even elevate the temperature of his workshop to over 100 degrees Fahrenheit (38 Celsius) to get the print finished properly. Even then, the 34 hour print damaged his Ender printer, but not before completing the part.

The hackery doesn’t stop there, because simply mounting the carburetor is only half the battle. Getting the engine to run properly with such a huge intake restriction is a new task all its own, with a deeper dive into fuel pressure management, proper distributor timing, and instrumenting the car to make sure it won’t self destruct due to a poor fuel mixture.

While [Thunderhead289] hasn’t been able to check the mileage of his vehicle yet, just getting it running smoothly is quite an accomplishment. If silly car hacks are your thing, check out [Robot Cantina]’s 212cc powered Insight and how they checked the output of their little engine. Thanks to [plainspicker] for the tip!

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See-Through Carburetor Gives A Clear Demonstration

July 6, 2021 by 19 Comments

Carburetors have been largely phased out on most automobiles, but for a century they were the standard, and still are on many smaller engines. Armed with a high-speed camera and with the help of his father, [Smarter Every Day] investigates these devices by experimenting with a DIY see-through carburetor connected to a real engine.

The purpose of a carburetor is to mix gasoline and oxygen to the correct ratio for combustion inside the engine. Gasoline flow from the tank to the bowl, from where gets sucked into the venturi. The choke valve adjusts the amount of air entering the carb, while the throttle controls the amount of air-fuel mixture entering the engine. It appears that the carburetor was made from a resin 3D printed body and manifold, with an acrylic cover and PLA throttle and choke valves. It was attached to a single-cylinder engine.

The high-speed footage is incredible, and clearly shows the operation of the carburetor and makes it incredibly easy to understand. If you’re interested, he also uploaded a second video with almost 80 minutes of detailed footage.

[Smarter Every Day]’s infectious curiosity has led to numerous fascinating projects, including a supersonic baseball canon and the backward bicycle.

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Fridge Compressor Turned Into Capable Little Four-Stroke Engine

December 2, 2020 by 18 Comments

Never underestimate the power of a well-stocked junk bin. Along with a TIG welder and mechanical ingenuity bordering on genius-level, all of which come to bear on this fridge compressor to four-stroke engine build.

The video posted by [Let’s Learn Something] is long, but watching it at double speed doesn’t take away much from the enjoyment. By using a piston-type compressor, a lot of the precision machining is already taken care of here. Adding the intake and exhaust valves, camshaft, timing chain, carburetor, and ignition system are still pretty challenging tasks, though. We loved the home-made timing chain sprockets, made with nothing more than a drill and an angle grinder. In a truly inspired moment, flat-head screws are turned into valves, rocker arms are fabricated from bits of scrap, and a bolt becomes a camshaft with built-up TIG filler. Ignition and carburetion are cobbled together from more bits of scrap, resulting in an engine that fired up the first time — and promptly melted the epoxy holding the exhaust header to the cylinder head.

Now, compressor-to-engine conversions aren’t exactly new territory. We’ve seen both fridge compressors and automotive AC compressors turned into engines before. But most of what we’ve seen has been simple two-stroke engines. We’re really impressed with the skill needed to bring off a four-stroke engine like this, and we feel like we picked up quite a few junk-box tips from this one.

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Miss Beatrice Shilling Saves The Spitfire

January 16, 2018 by 53 Comments

On a bright spring morning in 1940, the Royal Air Force pilot was in the fight of his life. Strapped into his brand new Supermarine Spitfire, he was locked in mortal combat with a Luftwaffe pilot over the English Channel in the opening days of the Battle of Britain. The Spitfire was behind the Messerschmitt and almost within range to unleash a deadly barrage of rounds from the four eight Browning machine guns in the leading edges of the elliptical wings. With the German plane just below the centerline of the gunsight’s crosshairs, the British pilot pushed the Spit’s lollipop stick forward to dive slightly and rake his rounds across the Bf-109. He felt the tug of the harness on his shoulders keeping him in his seat as the nimble fighter pulled a negative-g dive, and he lined up the fatal shot.

But the powerful V-12 Merlin engine sputtered, black smoke trailing along the fuselage as the engine cut out. Without power, the young pilot watched in horror as the three-bladed propeller wound to a stop. With the cold Channel waters looming in his windscreen, there was no time to restart the engine. The pilot bailed out in the nick of time, watching his beautiful plane cartwheel into the water as he floated down to join it, wondering what had just happened.

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