General Motors’ inline 4-cylinder Ecotec line of engines has gained a true cult following. Powering a plethora of compact and midsize sedans and SUVs these stout and affordable powerplants have made their way into the performance market in a big way. Offered in a number of different incarnations over the years and platforms, Ecotecs come in two displacements, 2.2 and 2.4-liters, and can be equipped with bespoke features normally reserved for high end or exotic engines, such as direct injection and Variable Valve Timing (VVT) systems.
The Ecotec has become an engine of choice for donor-project transplants. Their affordability and huge production numbers means they are plentiful and cheap foundations for desert racing, road racing, and drag racing applications. Aftermarket support for these compact GM four-pot engines has come in a tidal wave as a new generation of enthusiast culture welcomes them into the fold.
In this video, Cody Smith of Cloyes Gear and Products walks us through the timing and balance-shaft chain service on a non VVT example of GM’s Ecotec. Fooling around with the timing chains or belts in an interference engine can be a nerve racking task, especially when it comes to turning the key after your handy work is complete.
To ensure your pistons and valves don’t play musical chairs, Smith points us in the direction to ensure all the camshafts and gears remain indexed correctly. With the engine set at TDC for cylinder number one, the tear-down commences. A systematic process, Smith doesn’t just jump in and start turning wrenches resulting in a pile of hardware and gears.
Upon removing the cam gear from the exhaust camshaft, it is important to remember that some hardware is single use. “When you remove this bolt — it is a torque-to-yield bolt, you’ll get a new one in the kit — simply throw it away,” Smith casually instructs. Disconnected from the camshaft one might expect the gear to shimmy off the shaft with ease but valve spring overlap will preclude this operation — a little clockwise pressure unloads the gear/cam interface.
Moving into the timing chain case, the drive sprockets, tensioners, and guides are removed with care to keep track of their original location and any woodruff keys that index the gears. Installation of new chains is made easy by link color coding that intuitively refers to intake and exhaust balance-shaft drive.
One of the last decisions you will encounter when replacing your timing chain assembly in the Ecotec will be the type of timing chain tensioner you employ. According to Smith, “GM had a few different designs over the years — what you are going to get out of the Cloyes kit is the latest design. The tensioner must be installed in the deactivated state.”
The primary timing chain tensioner installs simply in the side of the cylinder head, and is activated with pressure applied to the chain bearing against the tensioner — the deactivated piston will pop out and keep the chain lash in spec. With a final step of torque hardware to the factory specs the service is complete.
With a step by step guide clearly illustrating the process, servicing the timing system of your Ecotec need not be a frightening job. If you are embarking on this sort of project and have further questions give Cloyes a call.