Jump to content
Forums Gone... but not forgotten!
Pontiac of the Month

Jack Leslie's 1957 Sedan Delivery

2024 April
of the Month

  • Rev up your passion for Pontiacs and join our vibrant community of enthusiasts!

    Whether you're a die-hard fan of classic muscle cars or you've got a soft spot for sleek modern models, you've found your home here at Forever Pontiac. Our community is dedicated to celebrating everything Pontiac, from the iconic GTO to the legendary Firebird and everything in between.

    Unlock access to expert advice, stunning photo galleries, engaging discussions, exclusive events, and more!

    Start your Pontiac journey with us today!

    Sign up now! 🏁

Car and Driver: Koenigsegg’s Camshaft-less Engine Explained, Watch It in Action [Video]


Recommended Posts

Koenigsegg Freevalve Engine 3


Suck, squeeze, bang, blow. These are the four cycles of the reciprocating, internal-combustion engine (ICE) Nikolaus Otto patented in the 19th century. The action of the intake valves that allow an engine to breathe and the exhaust valves that let it expel spent gases were, until very recently, defined by a shaft of eccentric lobes rotating twice as fast as the engine’s crankshaft.


Cams still spin twice as fast as the crank in the modern engine, but advances like camshaft phasing, or changing the relative opening and closing of valves in relation to the crank position, thus improving efficiency and performance, are commonplace. Honda’s VTEC actually changes the cam profile, increasing valve-event duration and lift at high rpm. BMW and Nissan have variable intake-valve lift systems that actually control the amount of intake air, as opposed to a physical throttle.


Koenigsegg Freevalve Engine 2


If you can imagine an engine free of the mechanical constraints of a steel camshaft (or four), you have the basics of the Koenigsegg Freevalve engine. As opposed to a camshaft dictating valve position, each valve has its own actuator controlling the valve position and timing. The idea has been around for years, and many firms have worked on bringing it to market, but supercar maker Koenigsegg has spent the last 13 years working on a camless head and it just released this nifty video:



Freevalve from Freevalve on Vimeo.


There are more potential advantages to a cylinder head of this design than we can list. In theory, a camless engine can run on any combination of its cylinders, with conventional or the more efficient Atkinson and forced-induction Miller cycles (thanks to their relatively bigger expansion ratios), and with lots of overlap, depending on the application. Or not. A naturally aspirated 1.5-liter four-cylinder capable of 40-plus mpg on two cylinders and well over 250 horsepower when wanted isn’t outside the realm of possibility. Only want to pump 87 octane? No problem, but when you decide to spring for the good, high-knock-resistance premiu, your engine could instantly crank out more power, especially if there is a turbocharger in the mix.


Koenigsegg Freevalve Engine 1


When camless heads catch on—there’s no if—the EPA’s gas-guzzler tax could cease to exist; at minimum, there would need to be a comprehensive rewrite of those laws, because every engine could nurse its way through EPA testing. The potential is nearly limitless at both ends of the spectrum: efficiency and power.


There are a few small downsides, however. There is a draw from the engine to run the pneumatic (an air compressor/accumulator of some kind is needed) and oil actuators (another oil pump), but those losses aren’t nearly as large the parasitic losses from the friction associated with driving cams, chains, and spring-loaded valves. Plus, those actuators are rather noisy and in their current state would never pass the public muster.


New technologies take a while to ripen before they’re ready to hit the produce stand. The good news is the ICE isn’t going anywhere soon. Aside from all the benefits, the camless head will also give the ICE a much-needed shot of adrenaline before electric motors take over the world.


Read Full Article

Link to comment
Share on other sites

Tired of these Ads? Register Today!

I've wondered why they hadn't gone to solenoids decades ago. That's what shifts your automatic transmission and has done for quite some time ... and it's solenoids making your multipoint fuel injection work too.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Tired of these Ads? Purchase Enhanced Membership today to remove them!
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.