Industrial Spark Plugs for Gas Engines: Cross-Reference Guide for Jenbacher, Caterpillar, MWM, MTU & Cummins
Industrial gas engines run continuously – power plants, biogas plants, landfill gas stations and cogeneration units often operate 8,000 hours a year or more. The spark plug is the smallest and cheapest part in that engine, and it is also the part that decides whether the unit runs smoothly or trips on misfire. Choosing the right replacement plug, with the right heat range, thread, gap and overall length, is what keeps output stable and maintenance cost low.
This guide lists the complete TORCH industrial spark plug range – 15 part numbers covering Jenbacher, Caterpillar, Cummins, MWM, MTU, Waukesha, 2G Energy, Jichai and SDG gas engines – with full technical data and the OEM numbers each plug replaces. If you already know the OEM number printed on your old plug, jump straight to the cross-reference table below.
Why Industrial Spark Plugs Are Different From Car Plugs
A spark plug in a car fires about 30 times per second and lasts 60,000 to 100,000 km. A spark plug in a stationary gas engine fires at the same rate but keeps doing it for thousands of hours, in a cylinder that is often running a lean mixture at high boost pressure and with aggressive combustion chemistry. That is a completely different duty cycle, and it changes the design:
- Gas-tight, vibration-proof construction: a pressed and welded shell instead of a simple crimp, so the plug does not lose compression sealing after months of continuous running.
- Iridium and platinum electrodes: precious-metal tips resist erosion far better than standard nickel electrodes in lean-burn combustion.
- Built-in resistor (1 kΩ to 12 kΩ): controls ignition energy and protects the coil and the engine control system.
- Exact overall length: on pre-chamber plugs, the plug, the pre-chamber and the ignition rod must match the cylinder head to the millimetre.
The plugs in this range are manufactured by Weichai Torch Technology Co., Ltd. in Zhuzhou, Hunan, China – a spark plug factory founded in 1961, recognized as a National High-Tech Enterprise and as a National Manufacturing Champion (Spark Plug), with an in-house test centre accredited by CNAS since 2017 and test programmes covering GB, ISO and JIS standards.
Quick Cross-Reference: OEM Number to TORCH Part Number
Find the number printed on your old plug (or on the engine parts list) in the left column, then read the TORCH replacement in the middle column.
| OEM Reference / Old Plug | TORCH Plug | Type | Engine Application |
|---|---|---|---|
| Jenbacher 462199 / 462203 / 401824 / P3 BERU 18GZ47, FBM80WPENS | A205 | Standard, M18 | Jenbacher J412GS, J416GS, G420G |
| Jenbacher 436782 DENSO 518 | A285 | Standard, M18 | Jenbacher J612GS, J620GS, J624GS |
| Caterpillar 243-4291 DENSO GI3-3 / GI3-4 / GI3-5 | A277 | Standard, M18 | Caterpillar G3500 / G3600, Cummins Q19G / QSV |
| Bosch 7308 | A289 | Standard, M18 | Waukesha 9390GL, Weichai M33 |
| Champion RB77WPCC Bosch 7301 / 7306 | A284 | Standard, M18 | Caterpillar G3500 / G3600, Cummins Q19G / QSV |
| MTU X52404500059 | A282 | Standard, M18 | MTU VGS1169BG |
| Champion RB75N STITT S-R80L | A166 | Standard, M18 | Caterpillar G3500 / G3600, Cummins Q19G / QSV |
| DENSO GE3-5 | A363 | Standard, M14 | Caterpillar G3400, Waukesha H1077G / VRG220 |
| 2G Energy 54-4 / 61014-08101 | S-R6A17 | Pre-chamber, M14 | 2G Agenitor 404 / 406 / 408 / 412 |
| Jichai 16V190 (pre-chamber) | SD1844P | Pre-chamber, M18 | Jichai 16V190 |
| SDG 71.5-500B generator sets | A252 | Pre-chamber with ignition rod, M18 | SDG 71.5-500B |
| MWM 12453572 / 12453556 | S-R6A12 | Pre-chamber, M18 | MWM TCG2020 |
| MWM 12453562 / 12343055 | S-R6A15 | Pre-chamber, M18 | MWM TCG2016 |
| MWM 12285295 / 12284432 | S-R6A13L | Pre-chamber, M22 | MWM TCG2032 |
| STITT S-R807BEX15-2 | A141 | Pre-chamber with ignition rod, M18 | Caterpillar G3500 |
💡 Not sure which plug you need?
Send us a photo of the old plug together with the engine model and serial number. We will confirm the matching part number, gap and torque before you order – free of charge and usually within a few hours.
Full Technical Specifications (All 15 Part Numbers)
“Thread length” is the length of the threaded section; “rod” and “HV line” apply to pre-chamber plugs supplied with an ignition rod and an exposed high-voltage lead. Design life is the manufacturer’s rating at rated load on clean pipeline gas.
| Model | Type | Thread | Hex | Thread Length | Resistance | Gap | Torque | Rod / HV Line | Design Life |
|---|---|---|---|---|---|---|---|---|---|
| A205 | Standard | M18 × 1.5 | 22.2 mm | 15.5 mm | 3–9 kΩ | 0.25–0.35 mm | 45–50 N·m | – | 8,000 h |
| A285 | Standard | M18 × 1.5 | 22.2 mm | 19 mm | 3–9 kΩ | 0.25–0.35 mm | 45–50 N·m | – | 2,500 h |
| A277 | Standard | M18 × 1.5 | 22.2 mm | 20.5 mm | 1.5–10 kΩ | 0.25–0.35 mm | 45–50 N·m | – | 4,000 h |
| A289 | Standard | M18 × 1.5 | 20.8 mm | 20.5 mm | 3–9 kΩ | 0.25–0.30 mm | 45–50 N·m | – | 4,000 h |
| A284 | Standard | M18 × 1.5 | 22.2 mm | 20.6 mm | 3–12 kΩ | 0.25–0.35 mm | 45–50 N·m | – | 4,000 h |
| A282 | Standard | M18 × 1.5 | 20.8 mm | 21.5 mm | 3–9 kΩ | 0.25–0.35 mm | 45–50 N·m | – | 4,000 h |
| A166 | Standard | M18 × 1.5 | 22.2 mm | 20.4 mm | 2–12 kΩ | 0.255–0.355 mm | 45–50 N·m | – | 2,000 h |
| A363 | Standard | M14 × 1.25 | 20.8 mm | 19 mm | 3–9 kΩ | 0.2–0.3 mm | 35–40 N·m | – | 4,000 h |
| S-R6A17 | Pre-chamber | M14 × 1.25 | 21 mm | 19 mm | 1.5–5 kΩ | 0.35–0.45 mm | 35–40 N·m | 130 / 290 mm | 4,000 h |
| SD1844P | Pre-chamber | M18 × 1.5 | 22.2 mm | 25.4 mm | 3–9 kΩ | 0.3–0.4 mm | 45–50 N·m | 385 / 459 mm | 4,000 h |
| A252 | Pre-chamber, ignition rod | M18 × 1.5 | 22.2 mm | 12.7 mm | 3–9 kΩ | 0.33–0.43 mm | 45–50 N·m | 362.5 / 468.5 mm | 4,000 h |
| S-R6A12 | Pre-chamber | M18 × 1.5 | 22.2 mm | 18.7 mm | 3–9 kΩ | 0.3–0.4 mm | 45–50 N·m | 284 / 470 mm | 4,000 h |
| S-R6A15 | Pre-chamber | M18 × 1.5 | 22.2 mm | 18.7 mm | 3–9 kΩ | 0.3–0.4 mm | 45–50 N·m | 196 / 264 mm | 4,000 h |
| S-R6A13L | Pre-chamber | M22 × 1.5 | 22.2 mm | 23.6 mm | 2–8 kΩ | 0.4–0.45 mm | 45–50 N·m | 275 / 930 mm | 6,000 h |
| A141 | Pre-chamber, ignition rod | M18 × 1.5 | 22.2 mm | 12.7 mm | 1–5 kΩ | 0.33–0.43 mm | 45–50 N·m | 368.5 / – | 2,000 h |
Standard or Pre-Chamber? How to Tell Them Apart
The engine decides which family you need, and getting this wrong means a plug that either does not fit or does not fire properly.
Standard spark plugs (A205, A285, A277, A289, A284, A282, A166, A363)
These screw straight into the cylinder head and fire directly in the main combustion chamber. They are used on the majority of gas engines up to roughly 2 MW, including Jenbacher J412/J416/J612/J620, Caterpillar G3400/G3500/G3600 and Cummins Q19G/QSV units. They are the simplest, cheapest and most widely stocked parts, and most of them are interchangeable on thread size (M18 × 1.5 or M14 × 1.25) – but the thread length, hex size and heat range must match the old plug exactly.
Pre-chamber spark plugs (S-R6A17, SD1844P, A252, S-R6A12, S-R6A15, S-R6A13L, A141)
On large-bore lean-burn engines the plug does not sit in the main chamber at all. It is mounted in a small pre-chamber where a richer mixture is ignited first, and the resulting flame jet then ignites the lean main charge. This gives stable ignition, lower NOx and better efficiency - but it also means the plug must be supplied as a complete assembly: plug, pre-chamber and, on many designs, a long ignition rod with an exposed high-voltage lead.
When ordering a pre-chamber plug, always quote the rod length and the exposed high-voltage line length, not just the thread size. Two plugs can share the same M18 × 1.5 thread and still be completely different parts: MWM TCG2016 uses 196 mm rod / 264 mm lead, while MWM TCG2020 uses 284 mm rod / 470 mm lead, and MWM TCG2032 uses an M22 thread with a 930 mm lead.
✅ Engine-by-engine summary
- Jenbacher: J412GS / J416GS / G420G → A205 (462199 family); J612GS / J620GS / J624GS → A285 (436782)
- Caterpillar: G3400 → A363; G3500 / G3600 → A277 (243-4291), A284 (RB77WPCC) or A166 (RB75N)
- Cummins: Q19G / QSV → A277, A284 or A166
- MWM: TCG2016 → S-R6A15; TCG2020 → S-R6A12; TCG2032 → S-R6A13L
- MTU: VGS1169BG → A282 (X52404500059)
- Waukesha: 9390GL → A289; H1077G / VRG220 → A363
- 2G Energy: Agenitor 404 / 406 / 408 / 412 → S-R6A17
- Jichai / SDG: Jichai 16V190 → SD1844P; SDG 71.5-500B → A252
Installation: Torque, Gap and the Sealing Gasket
Most “bad” industrial spark plugs are not manufacturing failures - they are installation failures. Three points decide whether the plug reaches its rated life:
- Cleanliness first. From unpacking to installation the plug must not touch dust, sand or metal chips, especially on the electrodes and threads. If a plug is dropped or the ceramic is impacted, mark it and have it inspected before use - do not fit it.
- Always use a torque wrench. Too little torque means poor heat transfer and gas leakage past the threads, which overheats the electrodes and shortens life. Too much torque stretches the shell, destroys the internal seal and lets hot gas escape through the plug body, damaging the ignition system.
- Keep the socket aligned. A plug inserted at an angle damages the thread, and in the worst case cracks the ceramic.
| Thread Size | Recommended Installation Torque (cast iron cylinder head) |
|---|---|
| M22 | 50–60 N·m |
| M18 | 45–55 N·m |
| M14 | 30–40 N·m |
For older engines with soft or aluminium heads, use the lower end of the range. Always follow the value on the individual data sheet of the plug you received if it is more specific than the general table.
Always fit a new gasket. The outer sealing gasket deforms on first installation and loses its elasticity under thermal stress, so a used gasket will not seal again. The gasket has two different sides: the smooth side (no bumps on the inner circle) faces the spark plug sealing surface, and the side with four bumps faces the cylinder head mounting surface. Fitting it the wrong way round is a common cause of leaks.
When Do Industrial Spark Plugs Need Replacing?
Spark plugs in continuous-duty gas engines are consumables. Working life in this range runs from 2,000 hours to 8,000 hours, depending on the plug family, gas quality and load profile. Engines running biogas, landfill gas or coke oven gas normally wear plugs faster than engines on pipeline natural gas, and rich-running or overloaded units can halve the expected life.
Replace or inspect the plugs when you see:
- Misfire alarms and uneven running: the first and most reliable sign of electrode wear or a fouled plug.
- Hard starting or rough idling after a period of stable operation.
- Loss of power under load with no change in fuel supply or manifold pressure.
- Rising exhaust gas temperature on one cylinder compared with the others.
- Increased fuel consumption for the same output.
- Visible electrode erosion, cracked ceramic or heavy deposits during a routine inspection.
Practical routine: check the plugs, the gap and the torque at every 250 hours of operation, at every valve adjustment, and after every alarm or shutdown caused by ignition. Adjustable-gap plugs must be re-gapped to the specification above, and the outer gasket replaced after any re-gapping.
🔧 Pro tip for plant operators
Keep a full set of plugs plus two spares per engine in stock. A single misfiring cylinder can shut a cogeneration unit down at the worst possible time, and air freight on a small box of spark plugs is cheap compared with a day of lost generation. Bulk orders of complete engine sets are always cheaper per piece - talk to us about a stock package for your fleet.
Frequently Asked Questions
What is the TORCH replacement for Jenbacher 462199?
The A205 - M18 × 1.5, 22.2 mm hex, 15.5 mm thread length, 3–9 kΩ, 0.25–0.35 mm gap, 45–50 N·m, 8,000 hour design life. It also replaces Jenbacher 462203 / 401824 / P3 and BERU 18GZ47 / FBM80WPENS, and fits Jenbacher J412GS, J416GS and G420G engines.
What replaces Caterpillar 243-4291?
The A277 (M18 × 1.5, 1.5–10 kΩ, 4,000 h). If your engine was fitted with Champion RB77WPCC or Bosch 7301/7306, the equivalent is A284; if it used Champion RB75N or STITT S-R80L, the equivalent is A166.
What is the MWM TCG2020 spark plug part number?
MWM 12453572 / 12453556 → TORCH S-R6A12 (M18 × 1.5, pre-chamber, 284 mm rod, 470 mm HV line). For TCG2016 use S-R6A15 (MWM 12453562 / 12343055), and for TCG2032 use S-R6A13L (MWM 12285295 / 12284432, M22 thread).
Can I mix different plug brands in one engine?
No. All cylinders should use identical plugs - same part number, same heat range, same gap. A different plug on one cylinder changes its combustion timing and temperature, which shows up as imbalance and can trigger alarms on the engine controller.
Do you supply other gas engine ignition parts?
Yes. Together with these spark plugs we supply ignition coils, ignition cables and high-voltage leads, pre-chamber assemblies and ignition rods, plus the usual consumables for gas engine maintenance. Tell us the engine model and we will send a matched list.
Where can I buy TORCH industrial spark plugs in bulk?
From Fob Auto Parts – we are a TORCH spark plug distributor and supply the full industrial gas engine range to importers, distributors and service companies. Send your engine model or the OEM number on your old plug and we will quote the TORCH equivalent, the price per set and the lead time.
Fob Auto Parts as Your TORCH Spark Plug Distributor
Fob Auto Parts is a TORCH spark plug distributor and export supplier. TORCH is the spark plug brand of Zhuzhou Xiang Torch Spark Plug Co., Ltd. (now operating as Weichai Torch Technology, Hunan, China) – one of the largest spark plug manufacturers in China, supplying both vehicle makers and the aftermarket worldwide.
We supply the TORCH industrial gas engine range listed on this page in wholesale quantities, together with the matching ignition coils, HV leads and pre-chamber assemblies. Because we buy through the TORCH channel and hold the range as a distributor, we can quote the same plugs that OEM-branded suppliers sell at several times the price.
What buying TORCH through a distributor means for you
- Genuine TORCH parts: supplied in TORCH packaging with the part number and batch marking on the box, not unbranded copies.
- Full engine sets: 6, 8, 12, 16 or 20 plugs for one engine, or mixed stock for a service fleet.
- Cross-reference checked for you: send the Jenbacher, Caterpillar, MWM, MTU, Waukesha or Cummins number and we confirm the TORCH equivalent before you order.
- Distributor pricing: tiered wholesale prices for importers, distributors and service companies, with consolidated shipping.
If you buy spark plugs in volume – for a gas plant, a genset service company or an aftermarket distributor – ask us for the TORCH range price list. All spark plug enquiries are handled directly by our sales team.
Why Buy Industrial Spark Plugs From Fob Auto Parts?
- Right part the first time: we cross-check the OEM number, thread, reach, hex, resistance, gap and rod length before shipping.
- TORCH distributor: we hold the TORCH industrial gas engine range as a distributor, so you buy genuine plugs at wholesale tier pricing.
- Factory-direct supply: sourced directly from the manufacturer’s industrial range, not from resellers.
- Full engine sets: order a complete set for one engine or a stock package for a fleet, and we will pack it as a kit.
- Export experience: we ship worldwide by air express and sea freight, with the commercial documents prepared for import.
- Technical support: photos of old plugs, engine plates and parts lists are all welcome - we will tell you exactly what fits.
Need a Quote? Tell Us the Engine Model
Send us the OEM number on your old plug, or simply the engine make, model and serial number. We will confirm the correct part number, quantity per engine and price, and reply with a quotation and lead time.
Need TORCH Spark Plugs? Ask Fob Auto Parts
Include your engine model, the old plug number and the quantity you need – we confirm the TORCH part number, set price and lead time.
We reply within 24 hours.
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or email sales@fobautoparts.com