Citroën Dyane 6
The “Dyane 6” was announced at the Brussels Motor Show in January 1968, fitted with the Ami’s 602cc M4 engine. This came with an advertised maximum output of 28 bhp (21 kW; 28 PS) (SAE), supporting a claimed top speed of 115 km/h (71 mph), which was a useful improvement over the 21 bhp (16 kW; 21 PS) (SAE) of power and the claimed top speed of 100 km/h (63 mph) with which the Dyane had been launched.
The 602 cc engined Dyane did not replace the original 425 cc engined car. However, two months later, in March 1968, the 425cc unit was replaced, in a car now described as the “Dyane 4”, by an improved 435 cc engine providing 26 bhp (19 kW; 26 PS) (SAE). The extra power came from changes including not only the slight increase in cylinder dimensions, but also an extra 2 mm of carburetor diameter and a raised compression ratio. Although there was a price to be paid in terms of higher fuel consumption, the listed top speed went up to 105 km/h (66 mph) and acceleration was measurably less anæmic.
In September 1968 the M4 was replaced by an improved 602 cc engine featuring higher compression pistons and forced induction from the engine fan giving slightly more power. As with the 2CV and Ami, cooling air was ducted straight to the heater, giving excellent demisting and heating. Mechanical contact-breakers were mounted at the front of the camshaft and located behind the cooling fan. The fan was mounted on a tapered shaft and secured with a bolt at the bottom of a deep tube (the top of which engaged the starter handle). As the mounting location of the points was not obvious to the uninformed, they were often neglected. The ignition coil fired both cylinders simultaneously (wasting one spark) and the spark plug wear was significantly greater than it should have been; 6000 miles was not uncommon for a spark plug.
Cylinder heads were held on with three studs and barrels slipped over the pistons. No Cylinder-head gasket was used, and since the wings unbolted in a few minutes, it was possible to remove the cylinder heads and barrels, change the pistons or piston-rings and reassemble the top end very quickly, using only a few tools.
It was based on the same platform chassis as the Citroën 2CV, sharing its advanced independent front to rear interconnected suspension. This comprised a central springing unit, running fore-and-aft in a tube on each side; each suspension arm on that side was linked to the spring, by a tie-rod and a ‘knife-edge’ pivot-pin. Early cars did not have conventional shock absorbers.
The squeak heard from most 2CVs and Dyanes as they go over bumps is due to lack of lubrication either inside the spring tubes or to the ‘knife-edges’. The front hubs kingpins need to be greased every 600 miles. Since this is often overlooked, the king-pins can be prone to wear, although some movement is acceptable.
The Dyane was also available with the “trafficlutch” – a centrifugal clutch which helped avoid stalling whilst in slow moving urban traffic.
Place of manufacture: Rennes-La Janais (France)
Date of manufacture: 1969
Total production: approximately 1,445,000 copies
Engine: M28 with 435cc
Price at the time: 7,656 Francs