A 1988 Land Rover Defender 90 has been extensively reworked with a Mercedes-Benz OM617 turbodiesel inline-five, an engine long regarded for durability and mechanical simplicity, in a conversion designed to blend off-road toughness with long-range dependability.
The build replaces the Defender’s original engine with a 3.0-liter OM617, a diesel first developed by Mercedes-Benz in the 1970s for use in large luxury sedans. Engineered to provide acceptable performance and fuel efficiency without excessive noise or vibration, the OM617 featured an all-iron block and head, indirect injection, a chain-driven single overhead camshaft and a mechanical Bosch inline injection pump. Its conservative internal design emphasized longevity over outright power.
Naturally aspirated and turbocharged variants of the OM617 powered a wide range of Mercedes models, including the W115, W123, W116, W126 and G-Wagen. Turbocharged versions introduced in 1978 helped establish the 300SD as one of the first series-production turbodiesel passenger sedans. Though modest in horsepower, the engine became known for steady torque delivery and the ability to accumulate extraordinarily high mileage with routine maintenance. Many examples have surpassed one million kilometers in taxi and daily-driver service.
The Defender conversion was completed by Ferraris and More of Garland, Texas. Supporting modifications include upgrades to cooling, fuel delivery, wiring and starting systems. A 120cc performance fuel injection pump, additional oil feed line, gear reduction starter, electric cooling fan with Revotec controller, new radiator hoses and fresh engine mounts were installed. Valves were adjusted and injectors cleaned as part of the process.
Output is listed at 149 horsepower and 236 pound-feet of torque. Power is routed through an Ashcroft R380 five-speed manual transmission and a dual-range transfer case, allowing rear-wheel drive or selectable four-wheel drive operation.
Notably, the OM617 in this Defender can operate on standard diesel, red diesel, biodiesel and JP-1 jet fuel, offering broad fuel flexibility for remote travel. The vehicle is offered for sale in Garland, Texas, with supporting records, a dyno sheet and a clean Texas title.
