Vintage Thing No.155 - Coates Orthoptera

The Coates Orthoptera just before last year's President's Trial

On the 35th Launceston trial earlier this year, many people were frankly amazed by the performance of Roger Ashby in his Coates Orthoptera. It sounded so crisp many of my friends thought it was running a Ford cross-flow engine and it nearly won the event outright.

I’d seen the Coates Orthoptera before and, in chatting to Roger in the past, discovered that, although the components are fairly commonplace, they are put together in a very effective manner.

The powerplant of the Coates Orthoptera at the Launceston trial featured a single downdraught 1.5" SU. This followed experiments with twin 1.25" SUs and Roger says the car ran a lot better.

The Coates Orthoptera is essentially an Austin 7 chassis with a Ford side valve 1172cc engine. This was quite a common combination during the fifties and typically used an E93A engine but the Ford motor in the Coates Orthoptera is a later 100E. These offer many advantages over the older unit, such as shell bearings on a crank with larger journals, enlarged valves and ports and adjustable tappets. Roger has also added an Aquaplane cylinder head, twin 1 ¼ SU carburettors on an Aquaplane Manifold, an Aquaplane Exhaust Manifold and an oil system converted to a remote spin off filter.

It's got a Kenlowe electric fan so the dynamo has been replaced by an alternator.

The front axle is from an E93A or Ford 10HP and is standard except for radius rods. The front brakes have been converted to hydraulic and the rears use a single hydraulic cylinder that operates the original cables. A bias valve is fitted to reduce rear braking should the need arise.

The chassis came from a late model Austin Seven of approximately 1935 vintage with boxed chassis members and with individual radius rods in place of the Ford/Austin originals.

Originally the drivetrain was all E93A and the gearbox is still E93A but the back axle is one for connoisseurs of small side valve Fords and consists of two halves of E83W van axles. This was following a chance conversation during the early hours of a rain soaked MCC trial while Roger was competing on a bike.

The Coates Orthoptera just looks right

As Roger puts it, “The E83W Fordson has an offset engine and prop shaft, this results in an axle with offset diff and two different length ‘banjos’. The clever mod of the time was to construct an axle of the two short halves, to create a considerably stronger axle of near enough the same track of an E93A axle. The down side is the very low gearing. Also, E83W purists get annoyed as this means two E83W’s have been destroyed for the sake of one special!”

Fordson E83W vans are quite cute but I remember my dad saying what terrible lighting they had with their six volt electrical systems. He drove one in the fifties when he worked for a builder's firm.

“When we purchased the axle," Roger continued, "we were shown a photograph in a 1960’s boy’s annual, possibly from the Eagle, of a Mr Coates and his Coates Special competing in a trial. If anybody has one of these annuals, we would appreciate a copy of the relevant page. It did not look to be the same vehicle and appeared to have front suspension based on the Ford Axle and - as I recall - two AMC/Matchless motorcycle type front fork stanchions. As there have been many changes to the car, this could be! Additionally, it had a different registration. However, on reflection this number may have been on a temporary basis and from one of the ‘donor’ vehicles!”

Probably the most effective Ford flathead powered Austin 7 in existence, the Coates Orthoptera demonstrates gestalt - it is greater than the sum of its parts.

The bare aluminium panels are mounted on a tubular frame. The section around the cockpit is formed on the original small bore tubing but the framework fore and aft of this was too badly corroded and had to be replaced as well as reskinned. 

"Godfrey Coates did tell me in our single conversation that he had used stressed steel panels in places. There was some example of this in the side of engine compartment but it was badly corroded and removed."

So what of the car’s history?

“It was first registered in Worcester in 1951 by the original builder Godfrey George Coates. We were able to obtain from the Worcester County archives a copy of the hand written ledger in which details of new registrations were recorded, the details of the registration being Number KAB 998, Name Coates Godfrey Geo., Address 14 Meadowfield Road, Rubery, Birmingham. The description of the vehicle is 'HP Special 1172' and below this was a note 'Built up from spares'. The HP has subsequently been crossed out and 'Coates' added with a note 'Name of Vehicle changed 25/5/54. The original date of registration was 4 Sep 1951.' "

About this time, Roger purchased the excellent Men and Motors of The Austin by Barney Sharratt. He was intrigued to see that the book was dedicated to George Coates, “Petit George de la maison Austin”, Herbert Austin’s first apprentice. George Coates was a young French refugee from the First World War and had a long and illustrious career with Austin. Could there be a link? Roger also found a mention in the book of George’s son Godfrey who worked in the experimental body shop.

“We wrote to Barney Sharratt, care of the publishers (Haynes, as ever with anything to do with this company, they were exceedingly helpful). Mr Sharratt contacted us and confirmed that they were the same Godfrey Coates and that Godfrey had assisted him with his book and he had seen pictures and newspaper cuttings regarding the special when it was built.”

I have this book in my library and it’s a fascinating read. George Coates features heavily in it. For example, he played a major part in the French version of the Austin 7 known as the Rosengart. He subsequently played a role in the development of the Austin Sheerline limousine and the 1800 BMC Landcrab.

Godfrey, George’s son and creator of the Orthoptera, is also in this book. He recounts a story where he had to repair the gearbox of a Maxi with Araldite after it had been holed whist testing in Portugal.  

Barney had spoken to Godfrey and he was happy to be contacted. Roger had a telephone conversation with Godfrey and he confirmed it was the car that he had built and expanded on some of his ideas that he had incorporated in the car.

“It became evident that the car - like many specials - had “evolved” over time, possibly not for the better. We sent some photographs but heard no more.”

“We had wondered if his health was failing due to his age, then a recent internet search brought Godfrey’s name to the fore in the acknowledgements for a book written by Martyn Nutland on Leonard Lord. An e-mail to Martyn confirmed that Godfrey Coates was still around but in poor health, an intermediary was identified, but subsequently we discovered that Godfrey had died. We had hoped to reunite the car with builder at some point.

“The intermediary, a very private person, confirmed that he had been an Austin apprentice working under Mr Coates. He described him as ‘the best metal worker in Austin’. He also told us that Godfrey had hand crafted all the body panels for the experimental mini’s and production was based upon these originals.

Roger Ashby contemplates his car

“We purchased this car in 1999 with the intention of driving in MCC events. I had been riding in their events on modern motorcycles for some years but damaged knees and impending surgery made the thought of sitting down for the events very appealing.

“Sadly, closer inspection of the vehicle and its components showed that every aspect of it required serious overhaul. It had a badly cracked block, no brakes, the rear axle was beyond repair and the tubular frame of the body was excessively corroded. The list was near endless.

“We started on what was to become a total rebuild of every part of the vehicle, but then interruption came from a totally unexpected source, Ruth discovered she was pregnant with the end result that our delightful daughter Suzy Constance was born, this event causing some disruption for a number of years to our many projects!

“With the advent of the formation of the HSTA (Historic Sporting Trials Association) we were spurred on to finish this project and actually drive it!”

Although originally registered as the Coates HP Special, Roger refers to it these days as the Coates Orthoptera.

“From the Pre-war Austin Seven Club book regarding the history of the works Austin 7 ‘Grasshoppers’ there is mention of George Coates taking the works cars to Le Mans… This was the first I had heard of Coates senior being involved in the Grasshopper saga, so I do not think it unreasonable to suggest that there might just be some influence from Dad on construction of the car and some works influence, hence ‘Orthoptera’ – the family name for grasshoppers!”

It has big-and-littles and will soon be blown, just like a dragster 

Roger says, “The car is currently being used to compete in ACTC/MCC long distance classic trials and local production car trials and has been prepared to compete in the HSTA (Historic Sporting Trials Association) proposed Heritage series of trials.

“I had hoped to compete in the 750 MC Trophy series in which there is accommodation of vehicles with Ford 1172 sidevalve engines and work was underway on components to enable the special to be raced

“To this end, a ‘super-tuned’ 100E engine is being prepared, a close ratio gearbox (from a 1172 powered Lotus) has been acquired and an E93A axle is awaiting modification. Following advice from 750MC members, a composite axle will be manufactured using a 100E crownwheel with the pinion chopped and welded to the front part of the E93A pinion, then 15” diameter wheels will be constructed from E93A centres and possibly VW rims.

“The rationale is that these three main components can relatively easily be changed and the car can then be used in both trials and racing/hill climbing.

“However, I think age/time may have bypassed me and I am going to concentrate on the ACTC/MCC events for the next couple of years and then review where I am.

“The next development is the building of a new engine utilising knowledge gained so far but with the addition of a supercharger, I am fitting an AISIN AMR 500 as used on a Subaru.”

Now that I would like to see!