The Jaguar D-Type engine was produced by Jaguar Cars Ltd. between 1954 and 1958. It shared many of its components with the C-Type engine, including the straight-6 XK cylinder block design which was initially 3.4 litre in capacity and later increased to 3.75 litre for selected ‘Works’ and competition engines and eventually 3.8 litre. There were numerous differences between the D Type engine and the other Jaguar XK engines of the same period. The configuration of the rear crankcase bolt array, to which the unique ‘D type’ bell housing was mounted, differed from all other models and the cylinder blocks were specifically machined in respect of this. This configuration inclined the engine towards the left side (exhaust side) by 8 ½ degrees yet leaving the D Type gearbox assembly in an upright position.
A dry sump system with external pressure and scavenge pumps was introduced for the Jaguar D Type engine, the sump and oil scavenge arrangement being thoughtfully designed and engineered to account for the angular position of the engine and the need for efficient oil scavenging. Contrary to the varied singular suggestions as to why the D type engine was designed to function inclined at an 8 ½ degree angle, it was in fact simply designed into the D Type as a whole for numerous reasons that offered benefits as a result of being engineered this way.
The pressure pump is a twin spur gear design, 8 tooth, 7 D.P. incorporating an inbuilt pressure relief valve which opens to allow recirculation between 45 and 50 lbs/sq.in. The dual scavenge oil pump is a triple spur gear design, scavenging oil from the front and rear of the cast sump catch pan. Both pumps are driven by a cross shaft gear assembly driven via the same skew gear which drives the distributor shaft spur gear, though, importantly, Jaguar specified a differing and rather critical backlash tolerance between this and the cross shaft spur gear.
We manufacture a complete new engine to fit the Jaguar D Type, the foundation of our engines being our new cast iron cylinder blocks in either 3.4 Litre, 3.75 Litre or 3.8 Litre variants. Numerous overbore sizes are offered for all engine types. We can also re-manufacture a D type engine using a clients original cylinder block if preferred, however, the correct early cylinder blocks are not only becoming difficult to source, but many are no longer realistically serviceable and certainly few of the original Jaguar cylinder blocks can withstand the rigours of Historic Motor Racing long term. We offer both wide angle and narrow angle cylinder head variants with a broad choice of camshaft specifications and porting options.
Our engines have the correct period Dry Sump lubrication system, having developed our own tooling, reverse engineered from original components and drawings made available to us. We firmly believe that our castings are the most correct and visually authentic examples in the world. As with all of our engine components, our dry sump assembles are machined and carefully assembled in house, along with the related oil pumps which offer the same high standard of build and finish, incorporating an improved gear design enabling an increased volume margin and continuous lobe thrust retention lubrication.
Our engines are supplied with or without the fuel system. We offer our own ‘in-house’ manufactured DCO3 carburettors with the correct inlet manifold for either wide angle or production cylinder heads. Both the Jaguar C9284 production inlet manifold and the XK1834 wide angle inlet manifold are produced by us to exacting standards and can be adapted to suit Weber DCOE carburation if preferred.