BOREHAM MOTORS

Naturally aspirated petrol engine that revs to 10,000 rpm

There was a time when even four-cylinder engines were furious revvers. Remember Formula 1 in the 1980s? The BMW M12/13 would exceed 11,000 rpm and have over 1,000 hp in qualifying settings. The Hart 415T roared like a swarm of enraged wasps. Both were small, nervous engines that revved as if there were no friction—pure expression of unfiltered engineering.

That was the first thing I remembered when I encountered the Ten-K, a 2.1L, 325 hp, 10,000 rpm four-cylinder engine created by Boreham Motorworks for the new Ford Escort RS—an engine that doesn't try to be modern, but rather alive. Starting with the pun in the name: Ten-K or 10K—the metric notation for its rev limit.

A few days ago, the British manufacturer close to Ford Boreham Motorworks presented its reinterpretation of the Ford Escort MK1, which is going into production. Along with this vehicle, the so-called Ten-K engine was also announced.

It is a 2.1L engine with double overhead camshafts, forged steel connecting rods, advanced fuel injection and a titanium exhaust system, among other things. It reaches its highest power at 10,000 rpm, there is no turbocharger, and it weighs only 85 kilograms, according to Autonews.

The project is the work of Boreham Motorworks, a British company whose name is a direct reference to the Ford division that created rally legends in the 1970s. The engine is a modern interpretation of the Cosworth BDA that equipped the Escort RS1600 — with the same concept of belt drive and four valves per cylinder, but with 2025 technology.

The engineering is cutting-edge and handcrafted in equal measure. The crankshaft, connecting rods, subframe, dry sump, and valve cover are all machined from solid blocks of steel. The cylinder head, clearly inspired by F1 engines, was designed to optimize intake and exhaust flow and allow you to reach 10,000 rpm. The block, produced with three-dimensional casting, has ultra-thin walls — lighter than those of a conventional engine, but with sufficient rigidity to withstand the pressures and loads of an engine that rotates almost 170 times per second.

And, as tradition dictates, the Ten-K has individual throttle bodies, guaranteeing instant response and that metallic roar that made rally Escorts legendary on asphalt and dirt. Development was led by two former Ford engineers: Simon Goodliff, former chief engineer for the brand, and Laine Martin, a specialist in engine calibration and control. The pair brought Boreham's technical heritage into the 21st century, delivering an engine that is both a tribute to the past and an affirmation of modern engineering.

Boreham sculpted the engine block using 3D printing technology. Two power outputs are available, 185 and 325 hp. The smaller engine will be paired with a four-speed manual transmission, while the larger Ten-K has a five-speed transmission.

The car's weight should be less than 900 kg, which guarantees excellent dynamics, but it will also pose a great challenge to drivers to tame the power, rear-wheel drive... By the way, Ford has given permission for this project.

The new Escort RS will have two engine options. In addition to the Ten-K, there will be a revised and enlarged version of the legendary original Cosworth BDA, now with 182 hp — an option for those who want more authenticity than speed. Each unit of the new Escort RS will be handcrafted, with production limited to 150 examples.

The price for the Boreham Motorworks Ford Escort Mk1 RS starts at approximately 340,000 euros.

Autonews