The structure of the factory-Riley TT Sprite AVC 20
This photo of Colin Readey is described by him as follows: ‘AVC 20 with original TT body in 1994; being refurbished with cowl nose.’ The photo clearly shows our car. Only the instrument panel This photo of Colin Readey is described by him as follows: ‘AVC 20 with original TT body in 1994; being refurbished with cowl nose.’ The photo clearly shows our car. Only the instrument panel has been changed today and is made of aluminium. It was probably converted in 2001/2002 to incorporate a large speedometer. The instruments are most likely still the same today.
Where do these photos and the descriptions come from?
I now have most of the images shown here in my possession, which I often received as original prints or as digital image databases from previous owners with the corresponding description.
Chassis
Why does the chassis number have an ‘R’?
Because it was clear from the outset that the chassis was not the original 1935 chassis, but rather chassis no. 3 from 1969/1970, which was rebuilt after the crash at Snetterton. This is also evident from Colin Readey's VSCC (Vintage Sports-Car Club) registration, where 1916R is noted. Even then, the correct international standard for historic vehicles was to stamp an ‘R’ for replica. Readey had several chassis made at the time, which has caused a lot of confusion and resentment to this day. It can be assumed that the Italian AVC21 also has one of these chassis.
Right picture:
Condition in 1998. Owner at the time: Georges Blättler.
Colin Readey writes in his report that the original chassis had to be replaced after the Manx Cup accident, as mentioned above. So the vehicle was on the road with a new ‘Harrison’ chassis from 1949.
The tube connection at the front was no longer curved, as on the original 1935 chassis. This Harrison chassis was also severely damaged in an accident on 21 September 1969 and replaced by Colin Readey. That is why our car is on chassis number 3. As already mentioned, this was built by Colin Readey in 1969/1970.
Straight Harrison design from 1965
The Harrison chassis during Colin Readey's restoration in 1962/1963. In the background, you can see the aero nose on the wall.
Curved design from 1935
The period mudguards, rear lights and position lights from the period of Readey's restoration from 1962 to 1964 are still on our car today.
Picture on the left from 1998. Picture on the right taken in Oulton Park in 1964.
Anyone who has read this website carefully will sooner or later wonder which parts of this vehicle are still original from 1935. We have also asked ourselves this question in detail and have come up with the following conclusive answers.
Body
The two photos above show the condition of the car in 1962, when Colin Readey took it over from Gordon Shillito. We are sure that this middle part of the body and the firewall have been preserved on our car to this day. The various holes and rivets that we can still find on our car today provide us with corresponding clues. We do not know which parts he had received with the car at the time.
Picture left: Condition of our car during the preparation in February 2024.
Picture right: The green arrows mark the holes for the cable fastenings that Colin Readey attached in 1966.
Picture right: Condition of the firewall in 1947 (Harisson).
The middle part of the body also provides many clues that it is an original part. As previously described, Colin Readey writes of the ‘original TT body’. The AVC 20 took part in the Tourist Trophy three times from 1936 to 1938. The shape and the rivets are also exactly the same. To my surprise, I found old holes during my search. I was pleased to find the three holes on each side that were drilled to mount the large windscreen in the first year. I also found the holes for the rearview mirror that was mounted later.
Rivets
Clearly visible: the now closed holes for the once-mounted rearview mirror and the windscreen mount.
Doors and cabin
The door openings on the body were enlarged on the left and right. These changes have remained in place to this day and were likely made by T. C. Harrison after the 1946 season. There was an additional aluminium cover for the passenger side to close the large cut-out for racing.
Evolution from 1935
From 1947
Today
The row of rivets behind the seat was removed on the driver's side. It is likely that the tall Colin Readey needed more space. I suspect that this change was made in 1969/1970.
Picture below: Situation before the rebuild in 1994.
Picture on the right:
The AVC 20 at Silverstone in 1971.
Rear
We are a little less certain about the rear end. It could well be an original part, especially since the wooden interior looks very old. In the photo of Colin's car, it is also visible that the new bonnet appears lighter at the sides than the middle and rear sections of the body, where the paint has been sanded off. It can therefore be assumed that Colin Reader received the rear section as a single part from Shillito. Unfortunately, the rivets were completely covered when the car was painted in 2002, so it is difficult to compare them with old photos. However, they are slowly reappearing due to the ageing process. The chance of finding the original rivets is increased by the fact that Colin's accident in 1969 was a head-on impact.
Picture on the right: Januar 1963
It is well known in the Riley scene that Colin Reader marked important original parts of the AVC 20. Our car has some parts that have such marks. However, we do not want to show these marks in close-up at this point, as they could be copied very easily.
We have found marks on the following parts to date:
- firewall
- front axle
- rear axle housing
- engine mount on the right
Other parts, such as the forged leaf springs or the gearbox housing, could also be original. However, we have too few clues to mention them here as a very potential original part.
Front
Shillito made major changes to his car for the 1948 season. He lowered the radiator 3 inches and also lowered the bonnet. This can be seen from the bulge at the front of the bonnet. This was done to gain space for the ignition distributor. This is still visible today. In addition, he fitted an aero panel made of aluminium. This panel and the bonnet belong to our car and are in our possession.
Picture on the right: Shillito with the AVC 20 and the front hood at the Blandford Trophy on
25 May 1949.
The lowered radiator for aerodynamic reasons can be clearly seen in the picture below. The front view of the radiator is practically square. This lowering has remained to this day.
Original Bob Gerard
Arrangement from 1948
Today
Brakes
We estimate that only 15 to 20% of the original parts from 1935 are still in existence. This figure is not extremely high, but we are convinced that our car has the highest proportion of original AVC 20 parts. Original parts are undoubtedly important, but racing cars in particular have been continuously developed and they tell a complete story. We would like to show some of these developments on our car below.
We start with the brakes. In 1935, the factory fitted rather small brake drums. But shortly before the outbreak of the Second World War, their size increased significantly. Initially the drums had only one vent, but Colin Readey added a second vent to the rear section of the front brake drums during the 1962-64 restoration. The condition of our car's brakes is exactly as they were in 1964, with the exception of the black paintwork, which was applied in 2002.
Picture on the right:
1946 Shillito
Picture on the left:
1935 B. Gerard
Picture on the left:
1964 Colin Readey
Picture on the right:
Zustand heute
In 1935, the factory TT Sprite AVCs ran with 15 to 20 brake drums without torque brackets.
We first see them on the AVC 20 in photos from 1946. Their attachment to the chassis still seems to be the same today.
From 1964 at the latest, we see that the cable has been replaced by a metal rod. Just as we still see it on our car today.
Suspension
As early as 1946, Cuth Harrison converted the front friction damper. This new version can also be seen on our car today.
From 1935
From 1946
As it is today
Im Winter 1947/48 baute Cuth Harrison auch die Hinterraddämpfer um. Dabei verwendete er hydraulische Dämpfer wie man sie heute ebenfalls immer noch an unserem Auto vorfindet.
From 1935 friction damper
From 1948 hydraulic damper
Today, hydraulic damper
Another modification was the addition of two additional dampers at the front. Colin Readey writes that this was done in 1948. However, the photos prove that these were not yet present in 1948, as the new Aero Nose was initially even slimmer and only received two additional bumps for these dampers in 1949.
Picture left: These additional dampers were removed in the 1990s. On our car, the mounting points on the front axle are still clearly visible.
Manx Cup 1948
From 1949
Colin Readey Silverstone 1968
Engine
The engines of the AVC 20 were replaced several times in the history of the car. Our car still has the 6 cylinder engine with Amal carburettor that was used by Colin Readey. We don't know if it is the same engine that Harrison and Shillito drove.
Le Mans 1935, 4 cylinder
From 1946, 6 cylinder with Amal carburetor
1964 to 1966, 4 cylinder
From July 1966, 6 cylinder Amal carburetor
Start of the 1966 season, 6 cylinder SU carburetor
As of today
Cockpit
Even though a lot has changed in the cockpit, you can still find a lot of the same things as back then. Today, the tachometer goes up to 8,000 rpm, while in 1935 it went up to 6,000 rpm. As can be seen in photos of Cuth Harrison, it was most likely replaced as early as 1946 when the car was converted from a 4-cylinder to a 6-cylinder engine. The handbrake, oil pump, petrol pump, steering wheel, gear knob and some A.R.I.C. instruments match the historical photo. However, the arrangement no longer matches.
Bonnet
Bonnet 1
With exhaust outlet and cooling slots at the top. From 1935 to approx. 1946
At first glance, the various bonnets used on the AVC 20 do not appear to be very interesting. However, my findings can help to roughly identify undated photos. Therefore, here is a list. We have bonnets no. 3 and no. 5b. Bonnet 5a was modified by adding an exhaust outlet on the side around 1996 (hence 5b).
Bonnet 2
Without exhaust outlet, without cooling slots.
From 1946 to approx. 1948
Bonnet 3
Without exhaust outlet, cooling slots at the top.
From 1948 to approx. 1964
Bonnet 4
With exhaust outlet and air intake, cooling slots on the right side.
From 1964 to approx. 1967
Bonnet 5a
Without exhaust outlet, cooling slots on the top.
From 1968 to approx. 1996
Bonnet 5b
with exhaust outlet and
cooling slots on the top.
Gearbox
The welded flange is a distinguishing feature of our gearbox housing. In the photo of 1963 with the built-in 4-cylinder engine, this does not appear to be the case, or it is a different gearbox, precisely because of the 4-cylinder engine.
