Paul King’s Escort Mk2 – the story!
(Re-printed from a while ago, because I think it’s interesting – Ed.)
I had been looking for a decent body shell for a couple of years, then I found this one on eBay. It had been imported from Germany after spending the last 15 years on display at a German Ford dealer. The owner had brought it over to England and stripped the interior for another classic car project and was selling off the rolling shell. It was in such good condition I decided to buy it. The next decision was what to build, 2.0 or a 2.5 litre car. I decided I would look into building a 2.5 litre, sighting the results achieved by a number of drivers in Mk2 Escorts against 4WD machinery.
Many people believe if you put a 2.5 Millington engine into a Group 4 Escort and bolt 15- inch wheels on it you will have a winner. Unfortunately, it is not that simple. You will end up with something slower than a good 2 litre Escort and be rather disappointed.
Over the years I have managed to dispel a few myths. Firstly, Group 4 Escort. People always look to the Rothmans Escort in Beaulieu as the perfect example of a Mk 2 rally car. It is a lovely machine but look underneath it and you will see 40-year-old technology (good technology in the 70’s), the only reason it was fast was the driver. I think it would be fair to say Ari Vatanen could win in a wheelbarrow! Secondly, 15 inch wheels, they look good, but in my experience offer little extra grip, are more expensive, heavy, and need a fair amount of work to get the car to handle properly. The only reason I use 15-inch wheels is for bigger brakes.
The build of my car started by looking at handling, weight saving and safety. Safety first, so I have used a full weld in T45 cage this has 3 advantages. Firstly, it offers far more protection in a crash (as opposed to a bolt in hoop with door bars type) There are 36 tubes to TIG weld in place! Secondly the T45 material is stronger and the thinner tube sections save around 10Kg over a CDS steel cage. Third, the cage extends from the front to rear suspension mounts so makes the shell totally rigid. I have also seam welded the shell. I am fortunate that I do welding at work so have done all this work myself. I have heard there is around 1000 hours of work to prepare an Escort shell, & this was about right. It took around 18 months of evenings and weekends!
The suspension is based on the Group 4 Escort, this is because the suspension principle and type have to remain the same to comply with the rules. Getting the suspension right is probably the most important part of the car. If you are running 15-inch wheels, the car will sit an inch higher, so it is necessary to lower the car by an inch to restore the ride height, the result of doing this means you have 1 inch less suspension travel. I have made up some front strut top mounts with the bearings 1 inch higher to give the travel back at the front and 15-inch wheel arches at the rear to restore the rear travel. I have also done some mods to the front suspension geometry to raise the roll centre of the front of the car.
This improves the nervous handling issues associated with the 15-inch wheels. The car now has 7 inches of total suspension travel. It is important to check all the suspension travel is free to travel to its extremes (with bump stops and springs removed) without anything binding up or tyres rubbing on body work. I have used AVO 3-way adjustable rear dampers and front struts. I found on my old car that these gave a good improvement in grip, gaining around a second a mile, and also improved tyre wear by a noticeable amount compared with basic non-adjustable types. With help from AVO I have modified the front struts to give improved braking feel, this modification is now incorporated on their current GP4 front struts. I have developed my own track control arms to reduce scrub radius on the steering geometry, and steering arms to zero out any bump steer (if this is not done the car feels unstable and wanders around under braking). Setting up the dampers is also a bit of an art, (high speed bump, low speed bump and rebound) it is easy to make the car worse with the wrong settings. The only way to get this right is to get some base settings, then do a test day at a circuit and experiment, you will soon feel what the bump and rebound settings do and their effect. The camber and castor settings are -2.5 degrees camber and 5 degrees castor and zero toe in, with a ride height of 130mm under the chassis rails. The total bump steer is within +/-0.25 degrees over 6 inches of suspension travel. People often ask about spring rates, there is no simple answer to this. What works on one car and driver may not work for another. I find the trick is to get the suspension as soft as possible to give good weight transfer, but not too soft so you hit the bump stops (this will cause the car to slide out unpredictably). I have gone down the route of using anti roll bars as this allows me to use soft springs to give good drive and feel under braking and the roll bars control the roll under cornering. The roll bar rates also control the oversteer and understeer. The roll bar pickup points are also adjustable so it is possible to soften the roll resistance. This improves cornering grip in the wet. I use a data logger to monitor suspension movement so can analyse problems in handling and see what is actually happening with suspension travel.
The biggest problem I found with going from a 2-litre car to a 2.5 litre car is brakes, hence the 15 inch wheels. Originally, I use an AP setup with 280mm discs to start with. These effectively burned out at the Abingdon rally, so I went up to 300mm discs. These warped badly, so ended up using a 300mm fully floating front disc with cooling ducts in the front spoiler. This works but is on the limit. The rear brakes are solid 240mm discs with AP callipers, and a spot calliper for the hand brake (for MOT purposes). The car actually has 2 hand brakes one mechanical and one hydraulic.
The engine and gearbox were probably the easiest, things to sort out, The Millington engine produces over 310 BHP and around 245 foot pounds of torque. There are other 2.5 engines with similar performance, but the Millington is very light weight at 83Kg. This is coupled to a Tractive 6 speed sequential gearbox. I fitted this with a Geartronics paddle shift system. It took a couple of goes to get the final drop gear right but settled on a final gearing to give 135 MPH max speed. I decided to retain the gear stick in the car, so if the technology packs up I can still continue with conventional gear changes.
The rear axle is a conventional Atlas type with watts linkage. I built this myself using my own design of rear hubs, based on the works fully floating halfshaft design. The rear diff is a Tran-x with 4.6 CWP. I have been experimenting with preload and take up ramps on the diff to reduce wheel lock up under breaking and reduce power oversteer. Currently there are no preload springs in the diff. and I am relying on the ramp angles, most people think this is wrong, but it works for me.
I have also considered the weight distribution, moving the rear bulkhead forward so moving the fuel tank forward, and the battery in the rear floor well so as to keep the rear weight overhang to a minimum. I have also used a floor mounted pedal box so the seats are further back to keep the crew weight near the centre of the vehicle. The bonnet and boot lids are glass fibre to save weight. An electric front screen allows the heater to be removed. The total car weight when empty of fluids etc is 895 Kg with a weight distribution of 463 / 432Kg Front / rear.
The result of all this is a car that is stable to drive and can give the WRC cars a run for their money, and the only one to date to beat Simon Mauger’s Mk2, not so bad for a car that has been built and maintained at home in the garage!
Drawing available from https://www.deviantart.com/01mark/art/escort-mk-2-dream-90727498