1974 Ford Escort mk1 - Third Rebuild

I had used the Escort on and off on several track days, as well as a little bit running about, but over the years I used ti less and elss, and it was spending more and more time in the garage.

I knew that I was never going to get around to using it as a track day car again, so around 2009 I decided to convert it back to road use.

It was an easy decision to make over what to do with it - on the road a engine on carbs just isn't going to cut it in modern traffic, plus having driven many turbocharged cars as daily drivers I knew that there was only going to be one option for me: the Cosworth YB.

It turned out to take almost the same amount of time to do this project as I had already owned the car for….

Sierra Cosworth 4×4 motor - ~220bhp as standard:

The engine was in reasonably good health. Pistons are okay, and we fitted new rings and bearings; one piston have slight signs of valve contact. The valves on the other hand were quite worn - we had to have all the valve guides replaced as well as a couple of valves replaced entirely (more than likely those valves that kissed the piston!).

One thing which we were not able to re-use was the turbo - it was a huge thing that would have been far too laggy for road use:

ECU is the standard 4×4 Weber-Marelli L8 unit, which has been fitted with an unknown ECU chip (presumably for the turbo and injectors that were fitted, but is pretty much an unknown quantity):

During reassembly, one of the things we found was that the exhaust manifold had a crack (very common on these), so it had to be welded. We took the opportunity to repaint it and the block in high temperature aluminium paint.

During this time we were getting the wheels powder coated and I had the idea to get the camshaft cover done in the same… so I sent it to the same place and then spent a bit of time painting in the Ford and Cosworth lettering by hand.

The exhaust is completely bespoke; no-one makes one for a Cosworth powered mk1 or mk2 Escort. We started with a stainless steel 2WD Cosworth downpipe (a Mongoose part, I believe) from the back of the turbo (which had to be modified to clear the bulkhead) and then added on a section of 3“ stainless exhaust parts to fabricate the rest of the system:

Here's the system being test fitted into place…

Downpipe to straight section under drivers floor:

Rising up under rear seat (note that the first silencer pictured here was designed to be removed and replaced by a straight section if the sound of the system turned out to be too quiet… which it did!):

First silencer rising up and running under axle (full weight on here, so the axle has plenty of room to drop without hitting the exhaust):

Final turn into the main silencer running right-to-left under the boot floor, then turning to exit from the left side of the rear panel:

Disassembly of ECU and removal of old ROM:

Cleaning and painting case:

Fitting Motorsport Developments EVO 320 ROM:

Fitting Motorsport Developments wasted spark control board:


How to make a set of plug leads for a wasted-spark Cosworth.

First, buy a set of non-wasted spark plug leads. These are cheap, even in good quality thickness like these:

Next cut the original distributor end off the cable - we won't be using it. Make sure you have bought enough of the correct, clip-on ends for your type of coil pack:

Slide the plastic clip-on connector on to the HT lead - if you forget to do this now, then you will have to completely re-do the cable afterwards!:

Apply some spray grease to the elbow and push the HT lead through:

Make sure you cut back enough of the outer cable so that the inner core can be bent back against the outer; the brass connector then crimps on:

Pull the rubber elbow back over the brass connector and slot it into the outer plastic clip-on part you push on to the HT lead earlier.

We mounted the coil pack and the twin ignition amplifiers on a thick gauge aluminium plate that was mounted in place of the heater bubble that we removed from the car years earlier

The original side mounted fuel tank was removed and a new purpose built alloy tank from Pro Alloy fitted in the boot instead.

Fuel pump is a Bosch 044 part, with both an pre and post-pump filter:

Fuel pipes exit the boot via a pair of bulkhead connectors, so no pipework running through a hole. The outlet and return lines are fastened to the shell of the car are regular spacings to keep everything tidy:

Radiator was changed to a combined radiator/intercooler combination from Radtec Cooling which fits into the space behind the front panel.

Coolant hoses are a bit of a nightmare. You can get a 'kit' from Roose Motorsport, but no mk1 is alike, and no mk1 Cosworth conversion is alike, either. So it's a case of use the parts as best you can, and then DIY the rest.

Most of the upper hoses work okay, but when you get to the bottom radiator hose, well, that's another story if you are using a header tank:

That's what we came up with. The rest are pretty simple, either following the original mk1/mk2 layout, or the Sierra layout:

Note that on my 4×4 engine I actually have a 2WD thermostat/top hose - it actually makes it a little easier to route the water pipes compared to the 4×4 part as its a lot less bulky.

Due to the extra heat from the turbo and exhaust pipework we fitted reflective heat barrier material over the areas that could potentially get the most abuse; around the turbo and downpipe, above the exhaust boxes, etc:

Wrap and paint for the downpipe, with reflective material for most areas of the bodywork that are near heat sources.

Around the turbo and downpipe:

Above exhaust pipework and silencers:

The front brakes were upgraded to a Hi-Spec Motorsport 4 piston caliper, 2-piece disc and bell (285mm x 32mm), along with braided hoses, pads and mounting hardware:


Fitting the speed sensor for the new Stack speedometer:

The brake pads for this kit are Volvo parts:

Front braking system completed:

Rear brakes were replaced and a Sierra Cosworth rear caliper fitted along with a solid, single piece disc. Handbrake cable is, I believe, mk5 Escort RS2000:

Unfortunately, after the first test drive we found that the modified handbrake cable mounting (one mount either side of the prop) was fouling the propshaft, so we changed it so that the cable was pulled exclusively on the left side of the tunnel, thereby missing the prop under compression:

Front suspension involved pulling out the old Bilstein struts and fitting new Gaz adjustable coilovers. These used to be supplied on an exchange basis (which mine were), but Gaz can now supply the entire strut and stub axle assembly from new. Here is how they initially looked:

After a few years sitting around the garage, and subject to a bit of overspray here and there, they looked a lot more tired… so I decided to repaint and re-assemble them:

The rear suspension was also upgraded with the heavy duty leaf springs being decambered (flattened) and a panhard rod and tower fitted:

Transmission tunnel required enlarging again, to fit the Borg Warner T5 gearbox as used on the 2WD Sierra Cosworth:

One thing we noticed since having the leaf springs decambered (to lower the ride height for road use) was that the extra width of the Capri 2.8 Atlas, coupled with the wide offset alloy wheels resulted in the tyres scrubbing the edge of the rear arches:

That wouldn't be much use - the first bump and the tyres are going to smack straight into the outside of the arches. The only solution is to narrow the axle (and half shafts) so that the tyres clear:

The axle and hub were sleeved with the inner tube (pictured above) that was press-fit before re-welding.

The final results were much improved:

The first thing to go in was plenty of sound proofing!

Then fitting interior panels (I custom trimmed these myself to match the dashboard and centre console) and underlay for the carpet (more sound proofing!):

Fitting the trim pieces around the roll cage:

Rear backrest and rear bench seat in place:

Fitting front seats and front seatbelts:

The front seats (Ford RS Turbo Recaros) and rear bench seat (bog standard mk2 Escort) were retrimmed by the excellent Hide n Seat custom auto trimming service. Their work really is outstanding.

Console installed, along with new steering wheel and new front wheel well kick-panels:

Bought a replacement 6-dial gauge pod blank in GRP and fit a selection a Stack instruments:

First attempt at making a centre console for the remaining gauges and switches:

It looked great, and I was really pleased with it… except it wouldn't fit :-( I ended up having to remake the console, but roughly to the same design.

This was to fit over the bulk of the additional electrical system which is contained on the top of the tunnel. The Sierra has a hell of a lot more wiring than an original mk1 Escort, and the addition upgrades I fitted only added more:

  • Automatic headlights
  • Instrument backlighting controls
  • Electric heater controls
  • etc, etc.

This is the majority of the wiring and additional electronics:

With the console in place it hides most of that mess. I also made a removeable to so that the gear lever / gearbox can be disconnected without having to take out the entire console:

1974 Ford Escort mk1

  • De-bumpered (front)
  • 5-hole cooling panel in front
  • Front chin spoiler
  • Entirely new complete window glass set, including heated rear screen
  • Painted in Porsche L8A7 ”Ruby Red Metallic
  • Sierra Cosworth 4×4 engine
  • Borg Warner T5 gearbox
  • Uprated T3 turbo
  • Radtec radiator and front mount intercooler
  • Roose motorsport coolant and boost hoses
  • Motorsport Developments EVO 320 ECU chip
  • Motorsport Developments bespoke engine hardness
  • Motorsport Developments wasted spark system
  • Motorsport Developments closed loop fuelling system
  • Custom 3” stainless exhaust system
  • Bosch 803 green injectors
  • 3 Bar MAP sensor
  • Bosch 044 fuel pump
  • Pro Alloy boot mounted fuel tank
  • Stack motorsport gauges (tacho, speedo, fuel, boost, water temp, oil temp, oil pressure)
  • Full leather interior retrim
  • Alcantara door cards
  • New seatbelts and rear belts fitted
  • Custom heater and heater/vent controls
  • New door and boot locks
  • New front and rear lights
  • New wing mirrors
  • Bias pedal box
  • Vauxhall Corsa 'B' electric power steering column, ignition barrel and control stalks
  • Power steering sensitivity controller
  • Hydraulic clutch conversion
  • Shortened Atlas axle
  • 3.7:1 final drive
  • Shortened single piece prop
  • Hi-Spec 4-piston 285×32 front brakes
  • Sierra Cosworth rear calipers
  • Compomotive MO 8×15's re-powder coated in gunmetal grey
  • 215/45×15 Toyo Proxes T1-R (front)
  • 225/50×15 Toyo Proxes T1-R (rear)

  • blog/escort_restore_3.txt
  • Last modified: 2021/03/06 16:32
  • by john