Lawn Mower Carburetor Improves Mileage On Old Sedan

May 16, 2022 by Bryan Cockfield 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!

Continue reading “Lawn Mower Carburetor Improves Mileage On Old Sedan” →

Powering A Backyard Railway With Compressed Air

May 5, 2022 by Dan Maloney 12 Comments

When you’ve gone to the trouble of building your own backyard railway, chances are pretty good that at some point, you’re going to want to add a locomotive of some sort. After all, nobody wants to be stuck using muscle power to move carts around. But what exactly are you going to power your locomotive with? And will it be up to the tasks you envision it handling?

Answering such questions calls for rigorous calculations using established engineering principles — or, if you’re [Tim] from the Way Out West channel on YouTube, just throwing a pneumatic engine on wheels and seeing what happens. The railway that [Tim] built is for his farm in County Cork, where he plans to use it to haul wood that he’ll make charcoal from. We’ve seen a little about his rails and rolling stock before, which has been a low-budget and delightfully homebrewed undertaking. So too with his pneumatic engine, seen in the video below, which uses cam-operated valves to control a pair of repurposed hydraulic cylinders to turn a big flywheel.

Using scuba tanks, [Tim] was able to power the engine for a full fourteen minutes — very encouraging. But would the engine have the oomph needed for real farm work? To answer that, [Tim] plunked the engine on a spare bogie, connected the engine shaft to one of the axles with a length of rope, and let it go. Even with no optimization and zero mechanical advantage, the engine was easily able to move a heavy load of sleepers. The makeshift pneumatic railway even managed to carry its first passenger, [Tim]’s very trusting wife [Sandra].

There’s clearly more work to do here, and many problems to overcome. But we really appreciate the “just try it” approach [Tim] employed here, and with a lot of what he does.

Continue reading “Powering A Backyard Railway With Compressed Air” →

DIY Prony Dyno Properly Displays Power Production

March 25, 2022 by Ryan Flowers 13 Comments

When hackers in the US think of a retailer called Harbor Freight, we usually think of cheap tools, workable but terrible DVM’s, zip ties, and tarps. [Jimbo] over at [Robot Cantina] looked at the 212cc “Predator” engine that they sell and thought “I bet I could power my Honda Insight with that.” And he did, successfully! How much power did the heavily modified engine make? In the video below the break, [Jimbo] takes us through the process of measuring its output using a home built dyno.

The dyno that [Jimbo] has built is a Prony Dyno, and it’s among the oldest and simplest designs available. A torque arm is extended from a disk brake caliper and connects to a force gauge. The engine is ran up to its highest speed, and then he brake is applied to the crankshaft until the engine almost stalls. A tachometer keep track of the RPM, and the force gauge measures the force on the torque arm. Torque is multiplied by RPM and the result is divided by a constant of 5252, and voilà: Horsepower. A computer plots the results across the entire range, and the dyno test is complete.

That only tells part of the story, and the real hack comes when you realize that the dyno stand, the force gauge setup and pretty much everything that can be built at home has been built at home. You’ll also enjoy seeing the results of some driving tests between the 212cc engine and its bigger 420cc brother, how even minor changes to the engine affect the horsepower and torque curves, and how that affects the Honda that he calls his “Street legal go cart.”

Speaking of unusual power plants, how about plant some hobby sized jet turbines on the back of your Tesla for fun?

Continue reading “DIY Prony Dyno Properly Displays Power Production” →

Running Methanol RC Engines On Gasoline

January 22, 2022 by Lewin Day 33 Comments

Methanol is a popular fuel for small engines used in radio-controlled models, but comes at a higher price than gasoline. It’s also harder to source and can be a mite corrosive, too. Gasoline comes with some benefits, but running it in a methanol engine usually requires some mods. [David] and [Bert] worked together to build a mixture controller for just this purpose.

The controller uses a solenoid to control the flow of gasoline to a conventional methanol-tuned carburetor for a small RC engine, allowing it to be accurately tuned to run gasoline well across the whole RPM range. Having gone through many revisions, all documented in a big forum thread, the latest version uses a Seeduino Xiao controller and a BMP280 pressure and temperature sensor for determining the right fuel/air mixture for the conditions. A small OLED screen can optionally be fitted to help with configuration of the mixture controller.

The system has worked well in testing, with [David] and [Bert] reporting that they have “converted engines as small as 0.3 CID up to large radials with this system.” It’s a promising tool that could be handy to have in the RC modeller’s arsenal.

These tiny engines have other applications too; they can make for one crazy power drill, that’s for sure!

A Giant Engine Needs A Giant Engine Stand

September 2, 2021 by Lewin Day 9 Comments

Engine stands are great to have on hand for when you need to work on an engine outside a vehicle. However, if your engine is particularly large, you might find off-the-shelf solutions difficult to find. [Liebregts] was recently contacted by someone in just such a pickle, who had an 8-litre Bentley engine from 1928 and nothing to put it on. Thus, constructing a custom engine stand was in order.

The original home of the hefty 8-liter engine.

The stand is built out of stout 50x50x4mm steel tubing in order to handle the weight of the gigantic vintage engine. It’s designed with an eye to ground clearance, such that an engine crane can easily slide under the stand when it’s time to lift the engine back in the car. It also allows the whole engine to be turned upside down, and even raised and lowered. This makes it easier to get to different parts of the engine, while keeping the center of gravity where it needs to be to avoid the whole assembly falling over.

It’s not a hugely complicated build, but it goes to show just how much of a difference it can make when you have the right tools for the job. With the engine out and on its stand, it’s much easier to work on and handle the many complicated tasks in its restoration. It also benefits from being custom built to suit the dimensions of the Bentley engine. Everything fits and it just works!

While few of us have rare 1928 Bentleys in need of an engine-out service, it’s a build that should serve as great inspiration for those working on similar tasks. Meanwhile, consider building yourself a custom engine crane to help out around the garage.

Japanese Rocket Engine Explodes: Continuously And On Purpose

September 2, 2021 by Lewin Day 62 Comments

Liquid-fuelled rocket engine design has largely followed a simple template since the development of the German V-2 rocket in the middle of World War 2. Propellant and oxidizer are mixed in a combustion chamber, creating a mixture of hot gases at high pressure that very much wish to leave out the back of the rocket, generating thrust.

However, the Japan Aerospace Exploration Agency (JAXA) has recently completed a successful test of a different type of rocket, known as a rotating detonation engine. The engine relies on an entirely different method of combustion, with the aim to produce more thrust from less fuel. We’ll dive into how it works, and how the Japanese test bodes for the future of this technology.

Deflagration vs. Detonation

Humans love combusting fuels in order to do useful work. Thus far in our history, whether we look at steam engines, gasoline engines, or even rocket engines, all these technologies have had one thing in common: they all rely on fuel that burns in a deflagration. It’s the easily controlled manner of slow combustion that we’re all familiar with since we started sitting around campfires. Continue reading “Japanese Rocket Engine Explodes: Continuously And On Purpose” →

Game Development Hack Chat

August 16, 2021 by Dan Maloney No comments

Join us on Wednesday, August 18 at noon Pacific for the Game Development Hack Chat with Kyle Donnelly!

Chances are we all have fallen into the time trap of computer games at one point or another. It’s easy to do — the worlds that games put before us can be immersive and addictive, and even if they’re populated by fantastical creatures hell-bent on our virtual destruction, they offer a degree of escapism and relaxation that can be hard to come by with any other form of entertainment.

But what does it take to build these virtual worlds? How exactly does one come up with all the ideas needed to make a game fresh and exciting? And once you’ve got the ideas, how do you turn them into the code needed to make the whole thing work? Kyle Donnelly has quite a bit of experience with the game development process, seeing his idea through from initial prototyping to working with a publisher and even getting the game demonstrated at conventions. Along the way, he picked up a collection of tips and shortcuts to make the process easier, as well as developing a small suite of tools to help set up and test game levels quickly and easily, and to deal with the custom physics of his virtual world.

Join us as Kyle stops by the Hack Chat to talk about game development from an angle that rarely gets much coverage — from the software side.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, August 18 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.