GAS ENGINE CONTROLS
The spark and the mixture, under control
Ignition modules and closed-loop mixture control for gas engines.
A gas engine needs the spark to arrive at the right moment with enough energy to light the mixture, and it needs that mixture to stay where it should. Those are two different control jobs. Gill builds for both.
Simulated engine. Move your pointer side to side to change the load.
- Ignition modulesUp to 12 cylinders and 3000 µs spark duration
- Closed-loop air and fuel controlAF120 keeps the mixture on target from exhaust oxygen
- Works with your engine controllerSits alongside the panel already on the package
- CAN, 4-20 mA and RS232Interfaces vary by model
Two control jobs
The engine does not give you the same job twice
Gill's gas engine controls cover two distinct parts of engine control.
Ignition modules control when each cylinder sparks and how long the spark lasts, delivering the energy needed to fire the plug. AF120 controls the air/fuel mixture in a closed loop, using exhaust oxygen from a lambda sensor to adjust the gas valve and keep the mixture on target.
They can work together as part of the same engine package. They are not competing products.
Ignition timing and energy
GS8, GS12 and GT6 control when each cylinder sparks and for how long.
Closed-loop mixture control
AF120 holds the air/fuel ratio on target from exhaust oxygen.
CAN across the range
AF120 additionally provides 4-20 mA and RS232.
Sealed to IP67
Every product in the range carries an IP67 rating.
Choose your control
Three ignition modules and one mixture controller
Cylinder count and spark duration separate the ignition modules. AF120 takes a different part of the job and works alongside them.
GS8 Ignition Module
General-purpose ignition for engines up to eight cylinders, supporting static and non-static ignition.
GS12 Ignition Module
For engines up to 12 cylinders, or where the engine needs the longest continuous spark, up to 3000 microseconds.
GT6 Ignition Module
The compact option, for engines from one to six cylinders and up to 13 litres, with spark duration up to 1500 microseconds.
AF120 Air/Fuel Ratio Controller
When the engine also needs closed-loop mixture control. Monitors exhaust oxygen with a Bosch UEGO lambda sensor and drives stepper or current-controlled bypass valves.
No single Gas engine controls does all of that. Our team can suggest a pairing.
All three ignition modules are configured and mapped through Gill software, the SparkZ GUI and the GillFire ignition mapping screen, allowing ignition timing to be set across the engine map during commissioning without changing the hardware. The GS8 is documented in the shared GS8 and GS12 manual rather than a standalone datasheet.
Choosing between them
Choose by the engine first
Start with cylinder count and displacement, then ask one more question: does the engine also need closed-loop mixture control? If it does, AF120 works alongside the ignition module. The datasheet tab gives the GS12 and GT6 figures exactly as the released datasheets state them; not stated means that datasheet does not give the figure.
| Specification | Compact enginesGT6 | Up to 8 cylindersGS8 | Up to 12 cylindersGS12 | Mixture controlAF120 |
|---|---|---|---|---|
| Choose it when | You have a compact engine, 1 to 6 cylinders and up to 13 litres | You need general-purpose ignition up to 8 cylinders | You need up to 12 cylinders, or the longest continuous spark | The engine also needs closed-loop mixture control |
| Function | Ignition | Ignition | Ignition | Air/fuel ratio control |
| Cylinders | 1 to 6 | Up to 8 | Up to 12 | Not applicable |
| Engine size | Up to 13 L (800 in³) | See manual | All horsepower and engine sizes | Not applicable |
| Spark duration | Up to 1500 µs | See manual | Up to 3000 µs continuous | Not applicable |
| Control | Timing and energy | Static and non-static ignition | Timing and energy | Closed loop, Bosch UEGO lambda sensor |
| Interface | CAN | CAN | CAN | CAN, 4-20 mA, RS232 |
| Configuration | SparkZ and GillFire | SparkZ and GillFire | SparkZ and GillFire | See manual |
| Ingress protection | IP67 | IP67 | IP67 | IP67 |
| Datasheet | Datasheet | Datasheet | Datasheet | Datasheet |
| Specification | Ignition, up to 12 cylindersGS12 | Ignition, up to 6 cylindersGT6 |
|---|---|---|
| Number of cylinders | 1 to 12 | 1 to 6 |
| Power | 12 / 24 V DC, 5 A | 12 / 24 V DC, 5 A |
| Spark duration | 500 to 3000 µs continuous | 500 to 1500 µs continuous |
| Maximum RPM | 4000 | 4000 |
| Timing | Global, individual cylinder, dual fuel | Global, dual fuel |
| Timing maps | 2D speed and timing, or 3D speed, timing and load, 5 maps | Not stated |
| Trigger methods | Single pickup, OEM disc and pickup, A3 or A5 conversion kit, GM distributor timing kit, drilled flywheel pattern | Gill timing disc and standard pickup, OEM cam disc, A5 conversion kit, drilled flywheel pattern for wasted spark |
| Software connection | RS232, DB9 female | RS232, DB9 female |
| Features | Tach output signal, shutdown ground, fuel valve sequencing | Tach output signal |
| Status indication | 3 integrated LED status indicators | Integrated LED lights |
| Application | All horsepower and engine sizes, up to 2 coils per cylinder | Engines up to 13 L (800 in³) |
| Fuels | Not stated | Natural gas, propane, LPG, landfill, digester and other biogas |
| Environmental | -40 °C to +90 °C, sealed to IP67 | -40 °C to +90 °C, sealed to IP67 |
| Datasheet | Datasheet | Datasheet |
Configuration and integration
Configuration happens before the engine leaves you
Gill software provides the tools to configure and map the ignition modules. SparkZ GUI and the GillFire ignition mapping screen allow engine builders and packagers to set ignition timing across the map during commissioning, then change it later without modifying the hardware.
The control also has to speak to the rest of the engine. CAN is available across the gas engine controls range, and AF120 additionally provides 4-20 mA and RS232. That interface decision is worth making early, so the control sits alongside the engine controller, panel and wider package rather than becoming an integration exercise at final assembly.
What to tell us
The useful answer is usually one engine detail away
Before specifying a module, tell us the engine. Our team can then confirm the appropriate ignition module and whether AF120 should sit alongside it.
- Cylinder count
- Engine displacement
- Static or non-static, where relevant
- Whether closed-loop mixture control is required
- Required interface
- Application or package
SparkZ GUI
Configure the ignition modules and set timing across the engine map during commissioning.
Download SparkZ →GillFire ignition mapping
The ignition mapping screen for changing timing later without modifying the hardware.
Download GillFire →Interfaces to match the package
CAN across the range. AF120 adds 4-20 mA and RS232 for the controller or panel already on the package.
View the specification →Applications
The application decides what the specification means
Generator sets, compressor packages and larger stationary gas engines each put a different weight on cylinder count, spark duration and mixture control.
Gas engine gensets and CHPGenerator sets running on gas need reliable ignition in a compact package. The GT6 covers one to six cylinders and engines up to 13 litres; the GS12 takes larger engines up to 12 cylinders.Gas engines and combined heat and power →
Gas compressor packagesThe GT6 is also suited to compact gas compressor packages, with configuration through the SparkZ GUI and GillFire mapping screen during commissioning.Industrial process →
District energy plantWhere the mixture needs to be held on target, AF120 provides closed-loop control from a Bosch UEGO lambda sensor alongside the ignition module.District energy plant →Technical specification
Four products. Different jobs.
| Specification | GT6 | GS8 | GS12 | AF120 |
|---|---|---|---|---|
| Function | Ignition | Ignition | Ignition | Air/fuel ratio control |
| Cylinders | 1 to 6 | Up to 8 | Up to 12 | N/A |
| Engine size | Up to 13 litres | See manual | All horsepower and engine sizes | N/A |
| Spark duration | Up to 1500 µs | See manual | Up to 3000 µs continuous | N/A |
| Control | Timing and energy | Static / non-static ignition | Timing and energy | Closed loop |
| Interface | CAN | CAN | CAN | CAN, 4-20 mA, RS232 |
| Configuration | SparkZ and GillFire | SparkZ and GillFire | SparkZ and GillFire | See manual |
| Environmental protection | IP67 | IP67 | IP67 | IP67 |
Supply voltage, operating temperature and spark energy should be taken from the released datasheets and manuals rather than duplicated here. GS8 has no standalone datasheet, so confirm its figures against the GS8 and GS12 manual before specification.
Technical resources
Everything you need to specify, configure and commission gas engine controls
Questions
Frequently asked questions
What is the difference between the GS8 and GS12?
Both are general-purpose ignition modules. The GS8 covers up to eight cylinders, while the GS12 covers up to twelve and provides continuous spark duration up to 3000 microseconds. The GS8 specification is held in the shared GS8 and GS12 manual rather than a standalone datasheet.
Which ignition module do I need?
Start with cylinder count. The GT6 covers one to six cylinders and engines up to 13 litres, the GS8 covers up to eight cylinders and the GS12 up to twelve. Spark duration is another differentiator.
What does the AF120 control?
The AF120 controls the air/fuel ratio of spark-ignited gaseous-fuel engines using closed-loop control from a Bosch UEGO lambda sensor. It drives stepper or current-controlled bypass valves and provides CAN, 4-20mA and RS232 interfaces.
Can I use an ignition module and AF120 together?
Yes. They perform different jobs. The ignition module handles ignition timing and spark energy, while AF120 handles mixture control.
How are the ignition modules configured?
The GS8, GS12 and GT6 are configured through Gill software using the SparkZ GUI and GillFire ignition mapping screen.
What interfaces are available?
CAN is available across the range. AF120 additionally provides 4-20mA and RS232.
What is the difference between static and non-static ignition?
The GS8 supports both. The detailed distinction should be taken from the GS8 and GS12 manual rather than inferred from the product page.
What supply voltage do the controls need?
Supply voltage and operating temperature should be checked against the current released datasheet or manual for the specific product.
What fuels are supported?
The AF120 is specified for spark-ignited gaseous-fuel engines. Specific fuel compatibility depends on the engine and package, so this should be confirmed against the application.
Have an application to discuss?
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