Modern industrial gas engines and CHP packages are increasingly systems-led: combustion, sensing, and control are tightly coupled. That changes what ‘good ignition’ looks like in many applications. In this article, we explore seven practical strategies we’re seeing make the biggest difference, especially where lean operation, variable fuel quality, and long run-hours are part of the job.

 

1) Treat Ignition As Part Of The Engine Fuel Control System

On electronically controlled engines, spark timing and fuel delivery are coordinated by the engine controller/ECU (in other words, ignition and fueling aren’t independent). When the ignition components drift (symptoms include a weak spark, inconsistent firing, higher required voltage etc), the control strategy often has to work harder to maintain stable combustion. This can show up as more correction, less headroom, and less predictable operation under load changes. In short: ignition quality influences how effectively the engine fuel control system can do its job.

What we recommend: when you’re troubleshooting performance, don’t separate fuel issue from spark issue too early. Look at them as a linked pair.

2) Upgrade Spark Energy Delivery For Lean-Burn Stability

Lean mixtures are attractive for their efficiency and emissions levels, but they’re harder to ignite reliably because flame development is slower and the misfire risk increases as mixtures become leaner. That’s precisely why advanced ignition approaches (and robust components) matter more in lean-burn engines. Research shows that increasing ignition energy can improve combustion stability and can also improve efficiency-related combustion outcomes in lean operation.

What we recommend: if your engine is tuned for lean operation, prioritise ignition components that hold spark quality steady across the service interval, especially under transient loads.

3) Stop Relying On ‘Compatible’ Parts In Industrial/CHP Duty Cycles

A part that physically fits isn’t necessarily a part that performs well under continuous-duty gas engine conditions. Industrial applications tend to amplify weaknesses: long run-hours, higher average temperatures, vibrations, and (often) demanding combustion strategies. The result is that generic or loosely cross-referenced parts can underperform, not because there is anything technically wrong with them, but because the application is unforgiving.

What we recommend: move away from “this should work” selection in favour of manufacturer-matched specifications (heat range, construction, electrode design etc) aligned to the engine family and duty profile. (We also caution customers against casual cross-referencing for the same reason.)

4) Specify Your Spark Plugs By Combustion Design, Not Just Engine Size

In the spark plugs UK market, we still often purchasing decisions made by broad engine category (‘it’s a 1 MW engine, so we use X’). That approach is increasingly outdated, as modern gas engines differ significantly in combustion chamber design, ignition strategy (including pre-chamber variants), and operating lambda targets. So plug design and thermal behaviour matter more than they used to. Pre-chamber concepts, for example, are used specifically to extend lean-burn capability by strengthening ignition/initial flame development in ways a conventional setup may struggle to match.

What we recommend: treat plug selection as part of the combustion system. Small spec differences can create meaningful changes in stability under lean or variable-load operation.

5) Build Around Consistency Across Cylinders (Not Just “Does It Run?”)

A common performance trap in multi-cylinder gas engines is accepting good enough ignition behaviour on average. The engine may run, sure, but cylinder-to-cylinder variation inevitably creeps in, especially as the plugs wear. That variation can present as uneven temperatures, inconsistent knock margin, or tuning that becomes increasingly sensitive. Even when you don’t see an immediate fault, inconsistent combustion can push the engine toward less efficient control behaviour and more wear-driving conditions.

What we recommend: specify ignition components and replacement intervals that keep combustion behaviour consistent across all cylinders, not merely functional at the start of life.

6) Borrow A Principle From Gas Turbine Engine Starting System Design: “Minimum Energy, Delivered Reliably”

This is a useful mental model. In a gas turbine engine starting system, the starter’s job is to rotate the engine fast enough to establish airflow and fuel flow for stable combustion; common systems include electric starters and air turbine starters driven by compressed air. The engineering focus is reliability of the start sequence and achieving the required conditions quickly and repeatably.

While industrial gas engines aren’t turbines, the principle translates well: ignition must reliably deliver the required energy at the right moment, across real operating conditions — not just on a test bench. That means you design for repeatability, not a ‘best-case’ spark.

What we recommend: if your application includes frequent starts/stops or rapid load swings, prioritise ignition robustness and repeatability, not only long-life claims.

7) Treat Ignition Data As A Diagnostic Input, Not Just An Outcome

One of the quieter shifts in modern gas engine operation is how ignition behaviour is increasingly used as an indicator of wider engine health. As control systems become more sophisticated, deviations in the required spark voltage, firing consistency, or ignition timing compensation can signal changes in combustion conditions long before a fault threshold is reached.

In practical terms, this means ignition components are no longer just enabling combustion; they are an integral part of how operators and control systems interpret what’s happening inside the cylinder. As spark plugs wear or fuel quality changes, the ignition system’s response gives you early insight into the fuel mixture quality, cylinder balance, and combustion stability. Engines configured to capture and respond to this information can then be tuned more accurately and issues addressed earlier, reducing the risk of performance drift going unnoticed.

What we recommend: when upgrading your ignition system, consider not only component durability but also how ignition behaviour integrates with your monitoring and control strategies. Treating ignition performance as usable data helps move engine management from reactive to informed, improving long-term stability without adding complexity.

Find Out More

For more information about how ignition upgrades can enhance your gas engine performance, please contact the team at RM Walsh today by calling 01782 983 376, or [click here] to send a message.

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In modern gas engines, ignition systems now interact closely with the engine fuel control system and combustion strategy. Check out our [latest blog] as we look at seven ignition upgrade strategies that are quietly improving performance in industrial and CHP engines

 


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