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Recently, we were entrusted with a very special piece of history: the fuel pump from a Gardner 4LK diesel engine for a Rolls-Royce. The owner had a clear vision. He said, “What I really want is a Gardner diesel in there, as my old man used to run them in our wagons back in the day. I grew up around them, and they’re just beautiful.”
The car had originally been running on its petrol engine, but it soon began knocking and overheating, making the switch to a diesel not just a preference, but a practical solution.
The 4LK Gardner engine had been sitting in his yard for decades and it was “gas-axed” out of some plant machinery roughly 40 years ago and left outside ever since. It had a higher RPM setting than the one later sourced from a marine engine, and it needed careful reconditioning to ensure reliability and performance.
One challenge that was always on the horizon was engine speed. The original Rolls-Royce petrol engine could rev to around 4,200 RPM, whereas the Gardner 4LK struggled to get above 2,000 RPM. Naturally, this would reduce road speeds.
We had always planned to fit an overdrive to help compensate, but in the meantime, Chris experimented with the fuel pump governor to see if he could increase its speed. After some careful work, he ended up creating a hybrid solution, combining elements of a commercial pump with those from a marine pump. The result was the best compromise between performance and reliability, allowing the diesel-powered Rolls-Royce to run smoothly without over-revving the engine.
Aesthetics were equally important throughout the project. The engine bay is filled with polished and painted components, as well as gold-passivated zinc finishes, creating a striking visual impression. The team did an exceptional job ensuring that the Gardner engine matched the surrounding themes and details, carefully replicating the level of craftsmanship needed to maintain the car’s overall character.
And of course, after all the careful work, the Gardner-powered Rolls-Royce runs beautifully. Smooth, reliable, and full of character, it’s a true testament to patience, skill, and attention to detail.
Interestingly, converting cars to diesel wasn’t entirely unusual. During and immediately after the war, petrol was still rationed, and diesel engines could run on vegetable or animal fats, making conversions more common than one might expect. By the 1950s, Gardner even officially offered diesel conversions for cars. While we never found records of Rolls-Royces receiving such conversions, similar projects were carried out on Jaguar XK150s and Series 1 Land Rovers, showing that the idea had real historical precedent.
The result speaks for itself. The Gardner-powered Rolls-Royce now runs beautifully, combining vintage character with modern reliability. The owner is thrilled with the performance and attention to detail, and here at Welham Diesel, we couldn’t be happier with how the reconditioned pump and engine installation turned out. It’s a project that reminds us why we love working on classic diesels, each one is a unique challenge, and seeing a happy customer at the end makes all the effort worthwhile.
Importance of Quality Diesel Fuel Injectors
Using high-quality diesel fuel injectors is crucial for maintaining optimal engine performance and reliability. Low-quality or counterfeit diesel fuel injectors can lead to poor fuel atomisation, increased wear and tear on the engine, and potential damage. Investing in genuine or reputable diesel fuel injectors ensures long-lasting performance and minimises the risk of engine problems.
Diesel fuel injectors are vital for the proper functioning of diesel engines. They ensure precise fuel delivery, combustion efficiency, and overall performance. Regular fuel injection service and proper diagnosis of diesel fuel injectors are essential for maintaining their performance.
Choosing high-quality fuel injectors also plays a crucial role in ensuring the longevity and reliability of your diesel engine.
If you need help with the repair of your diesel fuel injectors, contact Welham Group to find out how we can help you.