My first encounter with Cylinder Deactivation was as a small child, wandering around an old cotton gin in rural Texas after a long day in the fields. Our job was to move the cotton from the front of the wagon to the rear with giant pitchforks so we could get more cotton into each wagon. It was hot, sticky work. Afterwards we would ride the wagons into the gin to be weighed and then wait as they offloaded the cotton. This would sometimes take a while as there were quite a few farms in the area, all trying to get in the gin at the same time. My cousin and I would wander around the factory drinking RC Cola from the 10-cent soda machine and wait for our uncle to come and get us. These were simple times. The giant “Hit and Miss” engines loudly thumping along, driving flywheels as big as the wagons themselves. There were no guard rails or safety equipment, just a gentle reminder to “Watch it son.” From a crusty gin worker that invariably only had eight fingers.

The ”Hit and Miss” engines operated for weeks on end during July and August. These engines, designed in the late 19th century, were the technological grandfathers of our current variable displacement engines. These giant single cylinder engines utilized a centrifugal governor or “fly ball governor” to maintain a constant RPM. As the engine accelerated, the weighted balls would spin further and further out until they would mechanically deactivate the cylinder by holding the exhaust port open. This is where the expression “Balls to the Wall” comes from. (Steam engines used the same governor system to regulate speed and pressures in their engines)

Today’s engines are a little more technologically advanced than the old “Hit and Miss” engines, but the end result is the same. Today, cylinder deactivation is used to increase fuel economy and reduce emissions of engines during light load operation. During regular driving conditions, and engine will only use about 30% of its maximum rated power. In typical light load operation, the throttle valve is nearly closed, and the engine must work to draw air. This causes what is called “pumping loss”. During idle and low load applications, the engine is fighting against itself to draw and exhaust air. At larger loads the pumping loss is reduced by comparison. In an engine that uses cylinder deactivation, both the intake and exhaust valves are closed. As the cylinder rises and compression increases, the cylinder with closed valves uses that air to push the cylinder in the opposite direction. This creates an “air spring” effect that has an overall equalizing result. The end result is virtually no extra load on the engine.

The first attempt at mainstream automotive cylinder deactivation was in the 1981 Cadillac with its problematic V8-6-4 L62 engine. Cadillac, in conjunction with Eaton Corporation, developed the engine which used the industry’s first ECU “engine control unit” to switch the engine from 8 to 6 to 4-cylinder operation depending on the amount of power needed. The original multi-displacement system turned off opposite pairs of cylinders allowing the engine to have three different configurations and displacements. However, the system was troublesome, misunderstood by customers, and a rash of unpredictable failures led to the technology being quickly retired. During this time, both Mitsubishi and Alfa Romeo developed engines with cylinder deactivation to somewhat moderate success, but due to lack of customer response, they were later dropped out of their lineups.

ATech offers training to help instructors explore ways to improve their understanding and use of ATech equipment in the classroom. There will also be an opportunity to try out many different trainers ATech has to offer.  

Upon completion, participants will receive a certificate of attendance which can be applied towards your ASE continuing education requirements. Use the link below to register. 

A tour will be provided for you to witness the manufacturing process ATech Training utilizes 

There is no charge for the training, and ATech will provide lunch each day. Travel, lodging, and other expenses will be your responsibility.

The closest airport is the Greater Cincinnati /Northern Kentucky International Airport (CVG). The drive from the airport to our facility in Walton is about 20 minutes. ATech Training has arranged special rates with area hotels.

Please let us know if you are interested in attending any of these training days.

ATech Training is proud to offer Virtual Training Workshops. Sam Houston, ATech’s instructor, will explore the key concepts and principles that will enhance your integration of ATech Trainers into your education program.

This will be an open forum training opportunity and will allow for flexibility with your schedule and training needs. During registration, you can indicate which trainer you would like us to cover as well as, your preferred date and time for participating.

Our goal is to make this a customizable training experience. There will be plenty of

opportunities for Q&A and discussion throughout the seminar.

Upon completion, participants will receive a certificate of attendance which can be applied towards your ASE continuing education requirements.

Please let us know if you are interested in scheduling a Virtual Training Workshop Session.

We look forward to seeing you in our online training workshop!