In Episode 4 of Retropower’s Gordon Murray Mk1 build, the sills, floor and transmission tunnel are rebuilt, the front end is reshaped around the cooling and dry-sump plumbing, and the independent rear suspension starts to take shape. Then Gordon himself drops in to sit in the car and set his driving position.
Video: Retropower on YouTube · watch “Gordon Murray's MK1 Escort - Retropower Build Episode 4” on YouTube
What happens in Episode 4
Scratch-built sills (0:55). After the quality of the new quarters, the team expected good pattern sills. They were so poor (the swage line was around 8 mm out where it meets the quarter) that Retropower binned them and made both sills from scratch.
Floor and tunnel (2:22). Pinholes kept turning up, including under the seat crossmember, so the whole floor came out and went in as a complete repair panel. With the floor out, the team could clean and epoxy-prime the inside of the chassis rails. The bigger gearbox needed a taller tunnel. The front section is newly fabricated, while the rear is raised by joining old and new tunnel pressings at different heights so it still looks factory.
Front end and cooling (6:03). New radiator side panels and a new crossmember panel are shaped around the radiator, oil cooler and dry-sump tank. The radiator is raised slightly, leaving space beneath it for the line from the tank to the pump. The tank itself will be made to fill that space. There’s a cold-air intake hole on one side and a matching recess on the other for symmetry, and slots that let a spanner reach the oil cooler’s rubber mounts.
Rear suspension (9:09). The design now uses the diff casing for strength. A billet aluminium block, around 50 mm thick and machined from 6082-T6 before anodising, bolts to the back of the diff and carries one half of each wishbone. A tie bar joins the front and rear wishbone mounts. The engineer is clearly weighing every gram, conscious that Gordon’s own car exhibition shows the weight of every car on display.
Gordon’s visit (18:37). Gordon is surprised by how much metal has been replaced. The team’s view is that cars that look good outside often aren’t. In the seat, he asks for a steering wheel about an inch to an inch and a half smaller, and pedals offset to the right to make room for a footrest. That pushes the seat a long way back, which everyone notes is good for weight distribution. His verdict: a bespoke driving position means you “jump in and just feel right.”
Parts, tools and suppliers mentioned
- Complete floor pan repair panel. The pattern sills were rejected and replaced with handmade ones.
- Epoxy primer inside the chassis rails
- Fabricated transmission tunnel, radiator panels and crossmember panel
- Oil cooler on rubber bobbin mounts, dry-sump tank (to be made)
- Billet 6082-T6 aluminium rear diff carrier, anodised. The machining was done by a local machinist.
Lessons for your own Mk1
- Check repair panels against the car before you fit them. Retropower found the pattern sills unusable.
- Sometimes a full floor is quicker than patches. It also gives access to the inside of the chassis rails.
- Plan the plumbing with the front panels. Radiator height, the oil cooler and dry-sump lines all compete for the same space.
- Set the driving position before the interior is finished. Seat, wheel size and pedal offset change the whole cabin.
- Weigh parts as you go if weight matters to you, especially when moving away from the original live axle.
Mk1 context
A standard Mk1 tunnel is built for small four-speed gearboxes. Fitting a modern six-speed almost always means raising or rebuilding it. Footroom is famously tight, which is why offsetting the pedals is a common build mod.
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