Episode 5 of Retropower’s Gordon Murray Mk1 build steps away from the workshop. The team visits Cosworth, which is building the car’s engine, to see how a road-car Duratec becomes a Cosworth one. Back at base, they sit down with Gordon to settle the interior and the few changes he wants to the outside.
Video: Retropower on YouTube · watch “Gordon Murray's MK1 Escort - Retropower Build Episode 5 - Cosworth Visit” on YouTube
What happens in Episode 5
Cosworth’s history (0:54). The tour starts with the company’s early Ford-based engines and moves on to the DFV, which the presenter calls the most successful Formula One engine of all time. There’s also the YB that powered the Sierra and Escort Cosworths. The guide shows the original test cells where the DFV was developed. They are still used today, including for Duratec testing.
How a Cosworth Duratec is built (5:19). Cosworth buys Duratecs straight off Ford’s production line. Each one is stripped, washed, deburred, and crack-tested on the important parts. Cosworth then rebuilds it with its own bespoke dry-sump system with the scavenge pump built in, its own pistons and rods, and its own cam and valve-spring spec. The head is machined for better airflow, and it gets a roller-barrel throttle system, which leaves nothing in the way of the airflow at full throttle. Gordon’s spec keeps the standard crank; Cosworth’s higher-spec engines use a billet one. The talk also covers the choice between a revvy 2-litre and a torquier, longer-stroke engine, which the Cosworth engineer sums up as “horses for courses”.
A reminder of who it’s for (11:11). Retropower shows a plaque marking Gordon’s first Grand Prix win as a designer, which the team says came only a year after he joined Brabham, when he was 27.
Interior planning with Gordon (13:27). Rather than copy the RS-style side gauge pod, Retropower proposes extending the centre of the dash down to hold auxiliary gauges, rotary heater controls and the headlight switch. The warning lights are labelled in words rather than symbols. Gordon likes the period look. Next is the seat trim. He once had a smart car with Murray tartan seats and found a whole seat in tartan too much, so the plan is just a hint: one seat panel and a strip across the rear bulkhead. Tartan gauge faces get a firm “a bit OTT”. He wants a thin-rimmed wheel and a gear knob that looks like it came from the 1960s.
Rear seats and belts (18:01). A cross tube behind the seats will tie the rear turrets together and give the parcel shelf a curved, rather than square, join to the bulkhead. Gordon expects normal belts for everyday use, but he likes being held in the seat on a track day.
Exterior (22:01). The plan is to change very little. Gordon wants one subtle rear-end detail. They discuss slots or vents, but don’t want to break the Escort’s long, straight lines, which make it look wider. Blacking out part of the panel is another option. The exhaust exits on one side, through a deliberate semicircular cut-out in the rear valance for a 2.5-inch tailpipe.
Parts, tools and suppliers mentioned
- Cosworth-built Ford Duratec with a Cosworth dry sump (integrated scavenge), pistons, rods and cams
- Roller-barrel throttle system
- Bespoke lower dash panel for the auxiliary gauges, heater controls and headlight switch
- Murray tartan trim panel (one seat panel plus a bulkhead strip)
- Thin-rimmed steering wheel and a 1960s-style gear knob
Lessons for your own Mk1
- A crate engine isn’t the same as a built engine. Cosworth’s work on a stock Duratec shows where the money goes.
- Choose the engine for how you’ll drive. A high-revving 2-litre and a torquier long-stroke engine suit different cars.
- Decide the interior before the shell is painted. Dash and bulkhead changes mean cutting and welding.
- Use bold trim sparingly. A small flash of pattern often looks better than a full panel.
- Think about how belts and harness points will be mounted while the rear structure is still open.
Mk1 context
The standard Mk1 dash is simple. Sporting models added extra gauges in a separate pod. The Escort’s clean, flat flanks and straight waistline are a big part of its look, which is why restomod builders are wary of vents and body changes.
Related
- Series hub: all Retropower Gordon Murray Mk1 episodes
- Background: the complete history of the Mk1 Ford Escort
- More builds on video: Mk1 Escort build videos