was a 3.8-litre or 4.2-litre. Around the time of the later series 1 E-Types and 420G in 1968, about the same time as the arrival of the ribbed cam covers, the practice of painting the cylinder heads ceased. Many sources still describe the subsequent unpainted aluminium finish as "silver". Jaguar's colour-coding of its cylinder heads of the late 1950s and early 1960s can be determined from Heiner Stertkamp's list below. The only real anomaly is that the earliest 3.8-litre E-Types had an orange painted head (because they had 3 carburettors) but later changed to gold (because they had straight-port heads). Gold paint signified a straight port triple-carburettor setup from then until the demise of the Mark X. Silver/bare aluminium => 3.4 A-type head (Standard XK120, XK140 and MkVII with two H6 carburettors) Red => 3.4-litre with C-type head and 2 carburettors (XK 120 C and XK 140SE/M only) Light duck egg blue and later light green => 3.4-litre with B-type head and 2 carburettors (may appear as light blue, light green or light blue-green) Dark blue metallic => 3.8-litre with B-type head and 2 carburettors Orange => 3.4 and 3.8-litre with straight-port head and 3 carburettors Gold => later 3.8-litre and all 4.2-litre (until 420G and Series 2 E-Type) with straight-port head and 3 carburettors Cars with the straight-port head and only two carburettors did not have painted heads. See the complete table of XK cylinder head types as they relate to Jaguar and Daimler models at the end of this article. Engine block The block was made of cast iron (with the exception of some made of aluminium alloy for racing engines), with the crankcase split on the centreline of the seven-bearing crankshaft. The crankshaft was made of EN16 steel, heat treated prior to machining. An innovation was the fitting of a proprietary Metalastik vibration damper on the nose of the crankshaft to eliminate damaging crankshaft resonances. The design and materials of the bottom end of the engine hardly changed throughout its life, apart from the changes dictated by the respaced cylinders of the 4.2-litre version (also used by the 'new 3.4' litre version). The oil pump was changed after a couple of years from a relatively inefficient gear-type pump to a Hobourn-Eaton eccentric-lobe unit. Fuel system The pre-injection cars had either two or three SU, Weber, Zenith or Zenith-Stromberg carburettors of various sizes depending upon the model and