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Crank Triggers
Precise ignition timing is critical for optimum engine performance in high-rpm and racing applications. This is achieved using an input sensor like a crank trigger. These devices feed the ignition box or ECU the precise position of the crankshaft in its rotation so that spark can be delivered to the spark plug at the best possible moment, which will maximize performance. JEGS offers high-quality crank trigger kits for Chevy, Ford, and Mopar engines from the best manufacturers, which include MSD, Moroso, FAST, Holley, and others. View our wide custom and universal crank trigger kit selection of that will help keep your ignition timing optimized.
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Precise control over ignition timing is essential for engine performance in high-RPM applications. Camshaft-to-distributor drive gears, reluctor wheels and pickups all have tolerances and clearances that can cause a slight lag and inconsistencies in timing, especially at high RPMs.
Crank triggers are a great feature; they cut down on the number of rotating and mechanical parts in the ignition for more consistent timing and performance. Crank triggers send a real-time signal to the ignition box or ECU to inform it of the position of the crankshaft in rotation. Crank trigger wheels are mounted directly to the front of the harmonic balancer and are designed with either a series of teeth and gaps, or magnets. A pickup mounted close to the wheel senses the magnets or gaps, sending a signal to the ECU or ignition box, which then uses that information to regulate spark delivery. Installation can be tricky, but a properly installed crank trigger then allows you to fine-tune timing to best suit your performance targets and your engine's needs.
This is where you can find crank triggers from brands like Moroso, Chevrolet Performance, Aerospace Components, Holley and MSD, with all the related parts needed for installation. That includes crank trigger setups for Chevrolet/GM, Ford and Mopar engines, including Hall effect switches, speed sensor reluctors, wiring harnesses and connectors. All crank triggers and kits are designed with top-quality materials, precision manufacturing and comprehensive factory warranty coverage.
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MSD IGNITION
Flying Magnet Crank Trigger Kit GM LS Gen-III/IV, 6.560 in. Diameter Trigger Wheel
Part Number: 121-8618
Ships Tomorrow
Lowest price guarantee
MSD IGNITION
Flying Magnet Crank Trigger Kit GM LS Gen-III/IV, 6.560 in. Diameter Trigger Wheel
Part Number: 121-8618
Ships TomorrowLowest Price Guarantee
![8620 Flying Magnet Crank Trigger Kit Big Block Chevy [Red]](https://www.jegs.com/images/mini_100/100/121/121-8620.jpg)
![8620 Flying Magnet Crank Trigger Kit Big Block Chevy [Red]](https://www.jegs.com/images/mini_200/100/121/121-8620.jpg)
HOLLEY
556-176 EFI Crank Trigger System for GM Gen III/IV LS Engines (6.560 in.)
Part Number: 510-556-176
Ships on Sep 02, 2026Lowest price guarantee
HOLLEY
556-176 EFI Crank Trigger System for GM Gen III/IV LS Engines (6.560 in.)
Part Number: 510-556-176
Ships on Sep 02, 2026Lowest Price Guarantee
HOLLEY
556-172 EFI Crank Trigger System for Ford Small Block Engines (6.560 in.)
Part Number: 510-556-172
Ships on Sep 02, 2026Lowest price guarantee
HOLLEY
556-172 EFI Crank Trigger System for Ford Small Block Engines (6.560 in.)
Part Number: 510-556-172
Ships on Sep 02, 2026Lowest Price GuaranteeThe Advantages Of Purchasing Crank Triggers
There is more than one benefit to installing a crank trigger kit on your engine. The first is the ability to provide more precise timing than a distributor pickup setup due to less mechanical and rotating parts involved that create inconsistencies. Another benefit is the ability to convert to a distributorless system or front-drive distributor by providing input on where the crankshaft is in the cycle to an ignition box or ECU.
Provides More Precise Ignition Timing
A crankshaft trigger reduces the number of mechanical connections and areas of inconsistency that are found in a distributor pickup setup. The camshaft-to-distributor drive gear, distributor shaft, reluctor wheel, and pickup can all have clearances and tolerances that can cause timing variations, especially at higher rpms. A trigger wheel is directly connected to the crankshaft, minimizing any change in signal that is transferred to the pickup mounted nearby.
Allows The Conversion To A Distributorless Ignition
When converting to a distributorless ignition system, a crank trigger is needed to let the ignition box or ECU know where the crankshaft is in its rotation. This ignition input allows for a distributorless ignition system or a front- drive distributor to be installed depending on the needs for the application.
Crank triggers play a very important role in high performance and racing applications as well as engines with distributorless ignitions. It is important to understand what crank triggers are as well as how they work and how to install one on your engine. To help you with your search, we have provided answers to the below questions about crankshaft triggers.
What Is A Crank Trigger?
A crank trigger is an electrical component that provides an input signal to the ignition system based on the crankshaft position in its rotation, which will provide the most efficient timing of spark in the cylinders. It is primarily used in race applications as well as on engines that use ignition coil packs instead of a distributor.
How Does Crank Trigger Ignition System Work?
A crank trigger ignition system works with simple operation. A trigger wheel bolted to the harmonic damper spins with either a sequence of teeth and gaps or magnets. A pickup is positioned close to the wheel and when the magnet or gap is sensed, it sends a signal to either a computer or aftermarket ignition box. This information is then used by the ignition ECU to determine when to tell the coil to send voltage to either the distributor or spark plug to fire at the correct time.
How To Install Crank Trigger Wheel
The crank trigger wheel is installed on the front of the harmonic balancer with the correct side facing outwards. If a crankshaft pulley is used, the thickness of the trigger wheel will need to be matched on the pulleys of any driven accessories such as the water pump, alternator, vacuum pump, or any other belt driven component with spacers (on average about 3/8"). This will allow belt alignment to remain correct to prevent slippage and throwing.
How To Set Up Crank Trigger On Race Car
The first step in setting up a crank trigger is to install the trigger wheel on the harmonic damper balancer. Next, the pickup and mounting bracket are installed in line with the trigger wheel. The distributor rotor needs to be lined up with the #1 spark plug wire terminal under the distributor cap and the engine at top dead center (TDC) for the #1 cylinder. The pickup has two wires that will connect to an ignition box or computer as an input. In addition, the air gap between the pickup and the wheel needs to be close enough for a strong signal, but not too close that the trigger wheel makes contact. This is especially important under load and at higher rpms (typically between .025 to .050") where the distance can change to the pickup. Once all connections and hardware are confirmed in the correct position and tightened properly, the engine can be started. Timing can then be fine-tuned to meet your engine's needs.
Improve Igntion Timing With Crank Triggers From JEGS
Ignition triggers are important input devices that allow your vehicle's computer or ignition box know where the crankshaft is in the rotation cycle. This allows the correct moment and timing to be executed to send spark from the ignition coil to the spark plug. Browse our large selection of crank triggers that will help provide precise ignition timing and allow you to use a distributorless ignition system.