Underneath the distributor cap, the rotor spins to distribute the spark to respective cylinders. If the rotor fails to spin properly, spark timing will be disrupted, causing your car to stall. A bad distributor rotor also makes your car shake drastically and your engine unable to turn over. You don't want to experience such driving inconveniences, do you? So, you'd better replace your distributor rotor at the right interval or as soon as you observe the first sign of failure. Since it is crucial to your ignition system, you have to make sure that the replacement you'll get is efficient enough and will offer the best value for your bucks.
Contact material: brass vs. steel
The rotor spins past several contacts to pass on the high voltage coming from the coil into the right cylinder, so you should purchase a replacement that's outfitted with high-quality contact material. It must be corrosion resistant and precision machined to ensure precise gap for accurate delivery of spark. The most common distributor rotor contact materials are:
Brass. Since brass is a tensile metal, rotor contacts made from it won't easily break and succumb to corrosion. Compared to steel, brass is also better in conducting heat and energy.
Steel. Distributor rotor contacts that are made out of steel are more durable, and they ensure longer fatigue life.
Other factors to consider
- High quality materials
If the rotor is spring loaded, make sure that the springs are resistant to corrosion and are able to provide unrestricted flow of energy. Rotors with features or materials that protect them against arcing and cross firing are a great buy.
- Impact resistance
If you often use your ride in demanding driving conditions, such as racing and off-roading, you should purchase an impact-resistant rotor.
Most of the time, a rotor that's backed by longer manufacturer warranty is more durable than the ones that are offered with the industry-mandated standard warranty for auto parts.
- Attachment style
If you're a novice DIYer, it pays to get a rotor that ensures easy installation, with no modifications required.
The product's features, quality, and warranty will determine if it is worth your bucks. While high-quality and durable units come more expensive, they can save you from frequently replacing your rotor in the future. So if you don't want to end up spending more in the long run, you'd better shell out extra bucks now for a superior-quality rotor.