Vintage Thing No. 159 - Imhof Mk1 Special

Long before I ever became a Candid Provocateur, I stumbled across the Imhof Special. One of my best friends at school gave me The Book of the Motor Car, published in 1952 by The Naldrett Press Ltd and approved by the Society of Motor Manufacturers and Traders, no less. My favourite chapter was Building Your Own Car by A Godfrey Imhof, in which our hero made a competition car out of parts of Ford 10 and Austin 7 gleaned from scrapyards.

HRK55 was the first version of the Imhof special as described in The Book of the Motor Car  (Photo : Naldrett Press)

Who couldn't be inspired by such Boy's Own DIY initiative?

I later discovered that this A Godfrey Imhof was actually the Godfrey Imhof, or Goff Imhof, one of the original Candidi Provocatores who’d raced Singers before the Second World War prior to rallying and trialling Allards in the immediate post war period. He built the Imhof Special using his experiences of trialling the big V8 sidevalve engine cars and ushered in a new era of lightweight trials cars.

Soon after starting a new job in sunny Andover, I met Rob Robinson-Collins who became a very good friend over the years. Rob was an uber-fan for Allards and actually owned the lightweight Imhof special when I met him. However, the story of the Imhof special was anything but straightforward.

HRK55 unclothed (Photo : Naldrett Press)

Imhof had the original idea for a small trails special after driving down to the Maloja pass in a Ford V8 lorry to compete in a prototype Allard with a De Dion rear axle. Watching a floor show in a Geneva nightclub, it suddenly occurred to Imhof what an effective trials car would result if he matched up the De Dion layout in a small car with the engine between the driver and passenger, just like the forward control Ford they’d taken up to 72mph on the autostrada. Allard engineer Tom Lush was with him and together they hatched out various options on the backs of menus in the nightclub. 

This shows the central position of the supercharged engine in the original layout of the Imhof Special. (Photo : Naldrett Press)

As Imhof himself put it, “I suggested that we should make an ‘A’ shaped chassis frame, mounting an ordinary Ford 8 front axle complete with its transverse-spring at the sharp end of the ‘A’, and a De Dion rear axle at the bottom, with the engine somewhere at the cross stroke of the ‘A’. I thought such a chassis would be light, simple, easy to make and original. Tom, however, pointed out that Sir Herbert Austin had had a similar idea long ago and had used it in the Austin 7 and it would be far simpler for us to get hold of an old Austin 7 chassis. We also decided to use a Ford 10 engine."

The accompanying text did not state if the car made it out under its own steam. The body language suggests not. (Photo : Naldrett Press)

The first car was originally built in 1949. Imhof, being of agile mind, noted the RAC Regulations allowed the engine to be placed anywhere in the chassis, so placing the engine almost parallel to the driver achieved more weight bias to the rear. 

“When we got back to England, we had made up our minds to go ahead and started to collect the necessary bits and pieces. We found in a car-breaker’s yard an old Austin 7 chassis frame for twenty-two shillings. Although dirty and rusty, when stripped and cleaned it was found to be in fairly good condition. A secondhand Ford 10 engine and a Ford 8 gearbox were found. I also obtained an Arnott supercharger which had been fitted to a Hillman Minx belonging to my mother.

 “Next, we bought from a friendly Ford dealer a Ford 8 front axle complete with springs, brake drums, wheels and steering parts. By drilling the original Austin 7 bracket at the peak of the ‘A’ of the chassis frame, we found that this axle could be fitted by using special U- bolts to attach it. To give extra strength in the rear axle to stand up to the power which we hoped to get from the supercharged Ford 10 engine, we bought the rear axle assembly of a Ford 10 cwt van as the parts are more robust. This we intended to convert to De Dion.

“We put in an enormous amount of effort, including many late nights and weekends, in trying to get the car assembled, but there was far more work than one anticipated. We got professional help with the welding of extensions to the chassis frame and other difficult jobs. Friends volunteered to assist and without their help the car would never have been completed.

“As the date approached of the first trial for which we had optimistically entered, we had still a lot to do. We decided that it would be impossible to complete the making of a De Dion rear axle in time. However, as we were going to use a propeller shaft joining gearbox to the rear axle only 10 inches long, we could not allow the rear axle to move up and down appreciably; if we did, the universal joint at the back of the gearbox would be damaged, since of course it had originally been designed for only moving through a few degrees. So, we decided to bolt the rear axle assembly direct to the chassis frame, using only wood blocks. We knew this would give a very uncomfortable ride but we hoped that it would work as a temporary expedient.

“The body we constructed of 20swg steel on a framework of ⅜” diameter steel tubing. Two surplus aircraft seats were used as they were light and cheap. We struggled all through the night before the trial to complete the car. Wings and a small Perspex windscreen were hurriedly attached. At 5 am, the engine was started for the first time.

Imhof gradually smartened up the first Imhof special. This is before the radiator and windscreen were fitted. (Photo : Autosport)

“It did not run very well but we decided to press on. Then on the Thames Embankment the radiator burst and that ended our first trip.

“In the following fortnight we continued working on the car and made many improvements and modifications. We took it to have the carburettor tuned and this improved the running of the engine enormously.

“Then we took our car to Buxton for the Sheffield and Hallamshire Motor Club High Peak Trial and were delighted to find that we came third out of ninety-eight competitors and won a trophy. On the previous day we also were one of six cars out of over a hundred to climb all the hills and lose no marks. So we felt all the work and expense were justified.

It's clear that the front end of the Imhof Special was largely empty but this is without the radiator being fitted. (Photo : Autosport)

However, one day Imhof noticed the car was behaving oddly so asked his co-conspirator Jock Ross (who built and maintained his cars) to drive it. Jock took it for an outing and after going over a humpback bridge found the chassis had broken.

A new tubular steel chassis was then created in 1950, similar in dimensions to the Austin 7 chassis and the running gear from the broken chassis transferred over. This time the car had rear coil springs for suspension and a similar location for the engine. Again, the car continued with the registration HRK55 and was very successful.

Further development involved independent suspension at both the front and the rear by use of swing axles. A Marshall supercharged MG TC type with a TC gearbox eventually replaced the blown Ford  powertrain. 

Imhof registered his special HRK55 and it featured in Autosport for 22nd September 1950 from which the following extract is taken. 

"Last season, Godfrey Imhof appeared with an experimental vehicle specifically designed for trials. At first, it had no form of springing whatsoever and an undeniably crude finish. The little car was most successful and, after independent rear springing was added, ceased to be a “hop, skip and a jump” vehicle whilst storming hills.

The caption reads as follows. "Construction details of the interesting new 1172cc Imhof Special, The supercharged Ford Ten engine is housed in a compartment on the driver's nearside. A tubular frame has been adapted with "Split-axle" IFS. The turnbuckle between the seats is for the Andrex Telecontrol dampers." What isn't clear is where the driver put his feet. (Photo : Autosport)

"Lessons learned in the experimental car have been embodied in the well-finished Imhof Special of today. The necessary amount of weight towards the driving wheels has been accomplished by setting the 1172cc supercharged Ford engine very far back in the frame, carried in what almost amounts to a sponson, to the driver’s nearside.

This shows the layout of the helical springs and the Andrex Telecontrol dampers that could be adjusted from the cockpit. I wonder if the Andrex dampers had a settings for soft, strong and very long? (Photo : Autosport)

"The interests of a good power-weight ratio dictated the construction of a special tubular frame at the front of which is a V-shaped bracket carrying the transverse leaf spring and “split-axle” type of suspension. The rear is also individually suspended, this time by vertical helical springs aided by Andrex telecontrol dampers.

"A superstructure, made of welded steel tubes, carries the neat light alloy body and a fairly large-capacity petrol tank is mounted in the tail.

Tippy-toe stance indicates the all round swing axle suspension. (Photo : Autosport)

"In order to facilitate pylon-weaving and hairpin-manoeuvring, the car has an exceptionally small turning-circle. As can be judged from the photographs, ground clearance is more than sufficient for the roughest of rough stuff. In fact, the little car is a first-class example of a vehicle built solely for competition work."

The original Autosport caption read "Talk of the Trials World. Jack Ross "breakneck" bouncing in the Imhof Special as "Goff" directs it up "The Horror". Imhof won the premier award." (Photo : Autosport)

By 1952 the RAC started to standardise the trials car formula, given the range of interpretation of the regulations. Imhof had already forced a change concerning where the passenger could legally sit in his 1948 Allard known as the “Joke Car”, KLD5. 

Sounds familiar? KLD5 is Vintage Thing No.45, the ex-Imhof Candidi Provocatores Allard J1 that Rob Robinson-Collins now owns.

In 1953, the RAC introduced the key element was for the front engine spark plug of the engine must be a certain distance from the centerline of the front axle. This prompted Imhof to build a new and more conventional car and he broke up HRK55.