OEM cam gear vs adjustable cam gear

Cam gears are the toothed wheels bolted onto the camshafts and driven by a belt or chain from the crankshaft. They directly control how the camshaft rotates relative to the crankshaft's position, and with it, the precision of the entire valve timing.

What does a cam gear do?

A typical DOHC engine has separate camshafts for intake and exhaust, each with its own gear. The gears are turned by the timing belt or chain from the crankshaft. OEM cam gears are fixed - they do not allow any adjustment of the valve timing.

Why switch to adjustable cam gears?

Adjustable cam gears give you the ability to fine tune the camshaft's timing for better performance and drivability. There is no universal solution for the perfect position - it depends on the size of the engine, the camshaft 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 throttle response at low revs for city driving
• Optimise for the midrange on track
• Maximise top end power for drag racing

Adjustable cam gears are also needed to degree in the camshaft correctly - something that should, in principle, always be done when switching to a performance camshaft.

Quality plays a huge role

Not all adjustable cam gears are the same. Cheap alternatives share a common weakness: the bolts can slip. If the gear slips during operation, the consequences can be catastrophic - valves colliding with pistons, a wrecked cylinder head, or a completely destroyed engine.

This is what separates a good cam gear from a bad one:

• Machining: The teeth need to be precisely machined. Poor machining results in cam gears with poor grip that wear out prematurely.
• Material: Quality cam gears are machined from 6061 T6 aluminium, which exceeds OEM standard in precision.
• Tooth profile: Chamfered tooth edges extend belt life.
• Surface treatment: Hard anodising provides durability.
• Degree markings: Laser engraved markings make precise adjustment easier.
• Mounting: Helicoil thread inserts in the gear ring let you make multiple adjustments during tuning without wearing out the threads.

Summary

OEM gears work fine for a stock engine. But as soon as you upgrade the camshaft, mill the cylinder head or want to optimise performance, you need adjustable cam gears to set the valve timing correctly.

Meksta helps you choose the right gear for your engine. Contact us for advice.

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