Now that the Clairmonte is on the road again it seems more sensible to consider this as two separate topics. We have been waiting for the six cylinder Riley engine for the Mk VII to be built up by James Ricketts and this has allowed time for the Clairmonte to be completed, as well as my Q-car (an Austin Seven Chummy with a Reliant engine and hydraulic brakes - but that's another story!).
Progress with the Lotus Mk VII replica has been covered in two issue of "Historioc Lotus". It has taken me so long to post the images to this site usng Photobucket that I lost the whole message and have had to start again. I will post the second part later!
From "Historic Lotus No 54 Autumn 2008
As many of you will know, David Harvey and I bought the Clairmonte Special in April 2004 and decided not only to restore it, but also to build a replica of the car which Colin Chapman designed for Clive Clairmonte—the first Lotus Mk VII single seater racing car with 2 litre Riley engine, and which was changed into a two seater by Clairmonte before it was completed by Lotus.
The result of this decision was that we had to find or make all the parts that were used on the car when it was first built and, knowing that Chapman would always use a proprietary part (and modify it if necessary) rather than design one from scratch, we had to discover from which contemporary cars these parts were obtained. Here is the story of the most difficult parts.
Problem 1 - How to identify the front suspension upright!
Solving this was indeed a puzzle. I wrote to everyone I could think of to try to identify the car from which the upright had come, with total lack of success.
I then dismantled it and discovered that inside the casing was a perfectly standard Ford E93A Stub Axle with the steering arm cut off.
I then chanced to look at the photograph of the Clairmonte being worked on in Clive Clairmonte's factory (see below) and there was something about the upright which looked at odds with the part I had taken off the Clairmonte. For a start it didn't look anything like the one I was trying to identify, and had a very slender diameter at the upper end.
Closer examination was difficult due to the rather poor focus, but it became obvious that the steering arm was attached at a point near to the front axle spindle and consisted of a tube which was angled upwards to meet the outer end of the rack and pinion track rod, to allow the track rod to be in line with the upper wishbone for aerodynamic reasons.
So it looked as though Chapman had not been responsible for the design of the upright that I had taken off the Clairmonte.
Another little bit of information was then revealed. In 1953 the Clairmonte was taken to Goodwood. Clive's nephew Sebastian was there and he tells me that the Scrutineers failed the front suspension and would not let it race! Clairmonte vowed never to race there again, but for 1954 he modified the upright by encasing it in the black tube which I was trying to identify. He left the original upright unchanged, but it was now INSIDE a tube, and the steering arm was now a part from a TD MG, with part of the TD MG upright welded to the new upright at the top, instead of slanting up from the middle as Chapman had designed.
This caused me to look again at my upright, and I now realised that the whole thing was a fabrication, with the welds meticulously filed down to make it look like a forging!
The next thing that happened was I went to the 2005 Goodwood Revival and had a good look at the 500 racers. To my amazement many of them also used a Ford Ten Stub Axle with extended King Pin just like the original Lotus Mk VII design. I talked to one of the mechanics who was about my age and thus around at the time the Lotus Mk VII was designed, and he told me that most of the home-built 500s at that time used the Ford Ten Stub Axle in this way. Here is a picture of the Kieft 500 which shows how the Ford Ten stub axle was used.
I think Colin got the idea from the 500 chaps. He was good at picking up bright ideas, and this must have seemed a good one as he already knew about Ford Ten hubs. All he had to do was create something to bolt onto the Stub Axle to connect it to the Rack & Pinion track rod, and I think that this which the Scrutineers disliked.
So I have not copied Clive's heavy modification for the Mk VII replica, which must have added a large chunk of unsprung weight (which would have been anathema to Colin) but instead have produced a slightly stronger version of what he designed as is shown in the photo here.
Puzzle No. 2—The Wheel Centres.
The wheel centres looked familiar because they closely resembled the West London Repair Company (WLR) centres used by Colin and the Allen brothers on the Lotus-Austin Mk III. These centres were widely used on Austin Seven specials at the time, but were a little bit weak when used on heavier cars as we discovered with Adam Currie’s Mk IIIb at Goodwood when one collapsed whist it was being practised by Colin.
On the Clairmonte there are four wheel studs, not three as on an Austin Seven, so we needed to contact the WLR company to get some made - but they have gone out of business and no-one could put me in touch with anyone who had worked there to find out what had happened to the stamping dies. In the end we had to have the parts spun from heavy gauge sheet metal, the recesses for the wheel nuts stamped in a tool that had to be specially made, and then welded together. The result is fine but cost more than I care to remember!
Problem 3—The Halibrand Final Drive
Close examination of the photo of the Halibrand sitting in the frame at the Lotus works shows it to be rather different to what is now in the Clairmonte.
This photo was taken before the side covers had been replaced by specially cast members which would accept the back plates for the inboard rear brakes.
After a lot of searching of US websites we were able to discover a company making modern replicas of just the unit we needed, and have been able to get side members turned up to take the inboard brakes without needing to have castings made.
All thse images were given captions but Photobucket has lost them, and I have run out of time!
