Plant & Machinery Diesel Engines — Excavators, Dumpers & Construction Equipment
Diesel engines for construction plant and site machinery. Caterpillar, Perkins, Cummins, Volvo, Deutz, and JCB. When a plant breakdown costs you a day's dig — we have the engine to fix it.
Plant and construction machinery runs diesel engines at high load factors in harsh site environments — dust, vibration, temperature extremes, and extended working hours. Engine failure on site is a serious cost: a 20-tonne excavator off the ground for a week on a civil project can cost more than the engine replacement many times over.
Commercial Engines supplies reconditioned, remanufactured, and new diesel engines for the full range of construction plant and site machinery: excavators, mini excavators, dumper trucks, telehandlers, tracked dumpers, compressors, piling rigs, and road rollers. We stock and source Caterpillar, Perkins, Cummins, Volvo, JCB, Deutz, and Komatsu units.
A Plant Breakdown Costs More Than the Engine
When a 13-tonne excavator fails on a groundworks contract, the cost isn't just the engine — it's the standing plant hire, the idle gang, the subcontract delays, and the programme consequences. The engine cost is often the smallest part of the total impact.
We understand the economics of plant downtime, which is why we've built our stock and supply model around fast availability for the most common plant engine types. Call us with the machine make, model, and engine code — we'll confirm availability and fix a price, usually within the hour.
- Same-day despatch on most stocked plant engines
- Engine match confirmed before anything ships
- Site delivery and depot delivery available
- 12-month warranty on all reconditioned units
Plant Engines by Machine Type
We supply plant diesel engines across the full range of construction and site machinery categories. Our plant engine stock covers:
- Excavators (crawler and wheeled): Caterpillar C6.6, Komatsu SAA4D95, Hitachi Isuzu 4JJ1
- Mini excavators: Yanmar 3TNV, Kubota V3800, Perkins 403C
- Dumper trucks: Perkins 1004 and 1006, Cummins 4BT and 6BT
- Telehandlers: Perkins 1104, Cummins QSB 4.5, JCB Diesel (Perkins derivative)
- Compressors: Caterpillar C4.4, Perkins 1104, Deutz BF4M
- Road rollers and pavers: Cummins QSB, Perkins 1106, Deutz BF6M
- Skid steers and compact plant: Cummins QSB 3.3, Yanmar 4TNV
Engine Rebuild for High-Value Plant
For high-value construction plant — large excavators, specialist piling rigs, long-reach machines — a full engine rebuild is often the most cost-effective approach. When the machine is worth more than the rebuild cost, and the engine is otherwise sound, a workshop rebuild to OEM tolerance delivers a warranted engine at a fraction of replacement asset cost.
We carry out full in-workshop rebuild on plant diesel engines including Caterpillar C6.6, C7, and C9, Cummins QSB 4.5 and 6.7, Perkins 1104 and 1106, and Volvo D5E and D7E. Fixed price before work starts. Twelve-month warranty on completion.
- Full stripdown rebuild — not a patch and send back
- All components measured against OEM tolerances
- 12-month parts & labour warranty post-rebuild
- Fixed price and return date agreed upfront
JCB Engine Supply
JCB machinery runs Perkins-derived engines in most of their compact and medium-duty range, and Cummins engines in their heavier machinery. We supply reconditioned JCB plant engines across the range, including the 444 (Perkins 1104 derivative), the 448 (Perkins 1106 derivative), and Cummins QSB units used in the JS and 457 series. Call with your JCB model number and we'll confirm the correct engine reference.
Plant Engine Replacement Options
For construction plant, the right approach depends on machine value, urgency, and the extent of engine failure.
| Approach | Lead Time | Cost | Warranty | Best When |
|---|---|---|---|---|
| Replacement Reconditioned | 2–5 days | Mid-range | 12 months P&L | Fast return to work is priority |
| In-Workshop Rebuild | 1–3 weeks | Mid-range | 12 months P&L | High-value machine, original engine retained |
| Replacement New | Variable | Highest | OEM warranty | Machine under manufacturer warranty |
| Replacement Used | From stock | Lowest | 3 months | Lower-value or older plant |
*We'll advise on the best approach for your machine and situation — call with the machine type and failure description.
Engine Brands We Supply
We stock and supply engines from the world's leading diesel manufacturers. Call with a make, model, or engine code and we'll confirm availability and give you a fixed price.
Caterpillar
C4.4, C6.6, C7, C9 — the primary plant engine brand for large excavators, compactors, and site plant.
Perkins
1004, 1006, 1104, 1106 — used in JCB, Manitou, and most UK mid-size construction plant.
Cummins
QSB 3.3, QSB 4.5, QSB 6.7, QSC 8.3 — for large excavators, heavy dumpers, and specialist plant.
Komatsu
SAA4D95, SAA6D107 — Komatsu plant engine supply through our sourcing and rebuild network.
Deutz
BF4M, BF6M air-cooled series — compressors, generators, and remote plant without cooling systems.
Volvo
D5E, D7E — Volvo excavator and wheeled plant engine supply, new and reconditioned.
Applications & Use Cases
Wherever a diesel engine is critical to operations — on the road, on the water, in the field, or in a plant room — we have the right engine for the job.
Excavators
CAT, Komatsu, Hitachi, and Volvo excavator engine supply — crawler and wheeled.
Dumper Trucks
Perkins and Cummins dumper engines for site dumpers and articulated haulers.
Telehandlers
Perkins 1104 and Cummins QSB telehandler engines for JCB, Manitou, and Merlo.
Compressors
CAT and Perkins compressor engines for Atlas Copco, Kaeser, and Ingersoll Rand units.
Skid Steers & Compact
Compact plant engines — Cummins, Yanmar, and Kubota for mini machines and skid steers.
Piling & Specialist
Specialist plant engine supply for piling rigs, cranes, and heavy civil machinery.
Our CAT 308 mini excavator failed with a cracked block in the middle of a drainage contract. Commercial Engines had a reconditioned C4.4 in stock — confirmed the engine code on the phone, fixed price agreed, and it was on site by 8am the next morning. We lost one day instead of a week.