Cam gears are the toothed wheels bolted to the camshafts, driven by a belt or chain from the crankshaft. They directly control how the camshaft rotates in relation to crankshaft position, and with it the precision of the entire valve timing.
What does a cam gear do?
A typical DOHC engine has separate intake and exhaust camshafts, each with its own gear. The gears are spun by the timing belt or chain from the crankshaft. OEM cam gears are fixed; they allow no adjustment of the valve timing.
Why switch to adjustable cam gears?
Adjustable cam gears give you the ability to fine-tune camshaft timing for better performance and driveability. There is no universal recipe for the perfect position; it depends on engine size, cam profile and what modifications have been made.
By adjusting the valve timing with adjustable cam gears you can:
- Move the power peak up or down the rev range
- Improve low-rpm throttle response for city driving
- Optimize the midrange for track use
- Maximize peak power for drag racing
Adjustable cam gears are also needed to degree the cam correctly, something that should practically always be done when switching to a performance camshaft.
Quality matters enormously
Not all adjustable cam gears are created equal. Cheap alternatives share a common weakness: the bolts can slip. If the gear slips while the engine is running, the consequences can be catastrophic: valves colliding with pistons, a ruined cylinder head or a completely wrecked engine.
This is what separates a good cam gear from a bad one:
- Machining: The teeth must be precisely machined. Poor machining produces gears with poor grip that wear out prematurely.
- Material: Quality cam gears are milled from 6061 T6 aluminum to a precision that exceeds OEM standards.
- Tooth profile: Chamfered tooth edges extend belt life.
- Surface treatment: Hard anodizing provides durability.
- Degree markings: Laser-engraved markings make precise adjustment easier.
- Fasteners: Helicoil thread inserts in the outer ring let you make repeated adjustments during tuning without wearing out the threads.
Summary
OEM gears work fine on a stock engine. But as soon as you upgrade the camshaft, resurface the cylinder head or want to optimize performance, you need adjustable cam gears to set the valve timing correctly.
Meksta helps you choose the right gears for your engine. Contact us for advice.
Also read about timing belts and chains and dynamic compression.