Through their efficiency and possibly zero-emission biofuels, camless engines can be the future of internal combustion. One key player who strongly believes that is Christian von Koenigsegg, who recently gave the technology a proper push through his team over at Freevalve. However, while the four-seater Koenigsegg Gemera takes a Swedish electro-pneumatic valve system in series production, DIY engineering mastermind Wesley Kagan is looking for a somewhat cheaper aftermarket alternative. After many hours of trial and error, his camless Mazda 1.6-liter project led to a working and driving proof of concept, at which point Mr. Kagan decided to make his plans and code available to all tinkerers, free of charge.

Kagan feels that professionals with resources like dynamometers are likely to take this technology to the next level sooner than he can, partly because he considers himself to be a novice at programming. Soon enough, his YouTube description will be filled with CAD and other crucial data. The rest is up to you.

Camless engines are more efficient because their valves can be operated individually, allowing for custom lift durations depending on catalytic converter temperatures, performance modes, or the type of fuel used. When it comes to the hybrid Gemera, this is how Koenigsegg explains the benefits of its twin-turbo Freevalve three-cylinder named "Tiny Friendly Giant":

"The TFG has an estimated fuel consumption of 15–20 percent less than a typical modern four-cylinder two-liter engine with direct injection and variable camshaft. The Freevalves improve engine efficiency at part load by eliminating throttle losses since there is no throttle. Furthermore, Freevalves deactivates cylinders with Frequency Modulated Torque to further reduce fuel consumption. Freevalves are also capable of running the so-called Miller cycle, which is why the TFG can have a static compression of 9.5:1, which is high for a high-boost turbo engine. Using the Freevalve system to run for example the Miller cycle, gives the TFG high efficiency and high power at the same time. All factors considered, the TFG is one of the most frugal and most powerful production engines in the world for its size."

Before his 1992 Miata's 1.6-liter four-cylinder, Kagan put an earlier version of his camless head on a 6.5-horsepower Harbor Freight motor. It became the perfect accessory for his air-powered prototype head on the Mazda engine.

Version 2 of the Kagan design uses solenoids, which consist of a coil of wire and a movable armature to be activated by the magnetic field under current. Springs and spring retainers aren't needed, yet the rather costly solenoids require higher amps, as well as fancy transistors capable of running at both 12 and 24 volts, all while handling switches in 30 microseconds.

This running Miata is only the beginning of the affordable camless technology's journey, yet while Kagan keeps perfecting it in his free time, you're also invited to take it to the next level. Needless to say, the promise of all this is huge.

A 2021 Jeep Wrangler’s 3.6-liter V6 engine apparently tried revving to eight times its redline after the owner left the vehicle’s transfer case in low-range while flat-towing, The Drive reports. The resulting stresses tore the engine apart, yielding a scene that looks as if it might have been caused by a grenade.

The car website spoke with the foreman of a north Florida shop to learn more about the ruined white 2021 Jeep Wrangler Unlimited Rubicon that had been flat-towed behind an RV. From The Drive:
Tuten told The Drive that when the techs began diagnosing the vehicle, they noticed it had been left in “4-Low,” which is what you’d want when traversing rough terrain at low speeds, or if stuck in a rut—but most definitely not while being towed at highway speeds. For reference, the JL Wrangler manual explicitly states not to exceed 25 miles per hour with 4-Low engaged.

As you can see in the clip, the crankshaft is broken, the block and pan are in pieces, there’s no flywheel or clutch kit to be found, the catalytic converter is destroyed, the bell housing is toast, the manual transmission input shaft has been sheared, and — though it’s hard to tell — I’m fairly sure the passenger’s side upper control arm was bent by the flying debris. It’s just a huge mess.

But that’s what happens when you have lots of reciprocating mass moving far faster than it was ever designed to. The Pentastar Upgrade was really only ever meant to consistently rev to roughly 6,600 RPM. With the Rubicon coming stock with a 4.10:1 axle ratio and a 4:1 transfer case low range ratio, and with first gear at 5.13:1, the vehicle’s crawl ratio is 84.13:1. This means the engine spins 84.13 times as fast as the rear wheels do.

If we assume that the RV was towing this Jeep at 60 mph (we don’t really know how fast it was traveling; the shop foreman that The Drive spoke to guessed 55), we can use the fact that the Jeep’s stock 285/70R17 BF Goodrich KO2s are rated to turn 645 revolutions per mile to learn that, at that speed, the vehicle’s tires were spinning at 645 rpm. Here’s my math for that, in case you’re curious:

The 84.13:1 crawl ratio tells us that, when in first gear and low range, the engine spins 84.13 times as fast as the wheels. This means that, with the RV towing the Jeep at 60 mph, the Jeep’s wheels were trying to force its engine to spin at 54,264 RPM. That’s 8.22 times the engine’s 6,600 RPM redline. No wonder it blew up (If I had to guess, it happened well before 50,000 RPM).Towing a vehicle is a tricky process that requires thoroughly reading the owner’s manual. There are lots of factors in play, including ensuring that certain components spin and others don’t, and making sure that what is spinning is getting proper lubrication.

Read the Jeep Wrangler JL owner’s manual, and you’ll see that it firmly denounces towing a four-wheel drive vehicle on a two-wheel dolly, and it spells out specific rules for flat-towing (see above).

You’ll see that vehicles equipped with a manual transmission must be towed with the transfer case in neutral and the transmission in gear. Why is this the case? I reached out to two driveline engineers to find out, and the good news is: They both came to the same conclusion. Engineer 1:
Engineer 2 talks about an automatic, which Jeep says should be put into “Park” during flat-towing. But the same reasoning applies to the manual transmission:

So the short answer is: Putting the transfer case into neutral technically disconnects the wheels from the transmission, but the reality is that bearing drag and oil churning can still create a torque on the transmission output shaft. You don’t want the transmission output shaft spinning on its own for too long of a duration, because the input shaft must spin in order to properly lubricate the gearbox.

By towing the Jeep in gear, you hook the input and output shaft together and couple them both to the engine — the inertia of these connected parts should easily be able to resist whatever torque is sent to the transmission output shaft as a result of transfer case mechanical drag. Ergo, by being in gear, you can prevent a scenario where only your output shaft spins without the lubrication created by a spinning input shaft.

Tremec breaks down the lubrication issue on its blog, where the transmission company actually recommends disconnecting the driveshaft leading to the manual transmission (note: this likely refers to two-wheel drive vehicles or ones without a neutral option in the transfer case):
Though you may initially have thought upon seeing the blown up engine: “How the hell did an owner keep the Jeep both in four-low and in gear?” it should be clear by now that making such a mistake really isn’t that difficult do. You’re supposed to tow the vehicle in gear. The only mistake the owner made, as far as I can tell, is keeping the vehicle in four-low. But just look at the shift knob above, and notice how the four-low shift lever position is just below the neutral position. It’s very possible that the driver simply pulled the lever too far, and didn’t realize that the vehicle wasn’t in neutral, but rather in low range.

If that’s what happened, it was tremendously costly, but seemingly easy mistake to make, and I feel for the owner.