Charge Motion-Control Valve

As cars evolve, markets change and new propulsion methods come and go – electric is one that came, went and returned – the classic petrol powered internal combustion has had to evolve as well. Even some of the old technologies have returned to help with the balance of economy, emissions and power.

Recently I wrote an article about variable valve timing, one method of keeping the balance equal. Another, which is specific to Ford is the “Charge Motion-Control Valve” which they patented back in 1999 and they use it on their petrol powered V8s to keep them relevant in a world that also has to balance a market that craves power (and normally aspirated V8s) with Governments flip-flopping over emissions and fuel economy targets.

Sometimes I feel that we are heading back to the 1980s with biturbos – smaller V6s and V8s with two turbos fitted and this can be seen with Maserati and then stablemate Ferrari using those configurations and we have seen some of the German marques also heading down that path.

Old schoolers though, still love the power and noise that comes from a normally aspirated V8 – the Big Three still produce great V8s with the Dodge Challenger, Chevrolet Camaro and Ford Mustang as popular as ever. Chevrolet use cylinder deactivation to help with the economy/power balance whilst Ford uses their patented valve on their 5 litre Coyote V8 – but what does it actually do?

It’s basically an air valve that controls the volume of air that gets mixed with the fuel. With variable valve timing the cam lobe is designed to keep the inlet port open longer to get more of the air/fuel mixture in to the cylinder. What the Charge Motion-Control Valve does is similar in that at low engine speeds, the valve restricts the flow of air into that mixture with the normal throttle reducing the volume of the liquid portion as well. This means a smaller explosion that converts to a lower power output.

When the engine speed rises and the main throttle is opened more, the control valve allows more air to be mixed with the fuel and so a bigger power stroke is created. On the Ford V8, each cylinder has a motorised butterfly valve in the intake and it has been designed to allow air to pass through even though the valve is closed – thus limiting the amount of air.

Interestingly, the Coyote V8 also uses a variable cam timing system as well, plus high pressure direct injection. In other words, this motor is packed full of technology. Many articles I have read about this control valve system claim that it is the valve only that balances the power and economy, however they fail to add in the variable timing and direct injection systems which contribute to the efficiency.

The funny thing is – after market component manufacturers have redesigned the plates that are part of the control valve body to give more power all the time by taking away the air restriction! This must be a cheaper mod than trying to strip out the system altogether.