The first production V8 from Jaguar replaced both the 6-cylinder AJ16 and the V12 engines following its launch in the XK8 in and subsequent use in the XJ8 in Many options were considered, including a new small inline 6 design but the ideas evolved towards a family of V6, V8 and V12 to both replace the existing engines and to be ready for new smaller cars. An important consideration was to make the engines shorter to be ready for future crash regulations. Following the purchase of Jaguar by Ford, the project was carefully re-evaluated and the decision taken to proceed but only with the V8 version at that time.
This decision meant the closure of the engine plant at the former Daimler works at Radford in Coventry. The first prototype engine was assembled late in and fired up on the 4 th November. Trevor Crisp and David Szczupak led the team which made the V8 into a compact unit which was carefully designed to fit into the existing X saloon and its proposed successor. The engine featured: fracture-split forged powder metal connecting rods, hollow one-piece cast camshafts and a reinforced Polyamide composite plastic intake manifold, which was light and provided thermal insulation.
This enabled Jaguar to accommodate an integral fuel rail into the manifold, reducing complexity and improving hot fuel handling. Interestingly, the Jaguar engineers stayed with the valve operation system they knew best, having already used it with previous engines. This meant direct operation with aluminium bucket tappets beneath the cams with shim clearance adjustment. The valve gear was extremely light but with large valve sizes to give low friction and good breathing for high power.
Proven chain-drive for the camshafts was chosen — years of experience with the V12 and AJ6 showed them to be durable and compact and avoided the need for the servicing needed with a cam belt. Variable timing actuators were fitted to the inlet camshaft sprockets to improve the spread of torque through the rev range, reduce emissions and improve fuel economy.
Once in production it was found that the plating was subject to attack from low-grade, high-sulphur, fuels and some engines had to be replaced under warranty. The plating was later replaced with cast-in iron linings. The twin cylinder heads were produced by Cosworth exclusively for Jaguar. A substantial aluminium bedplate, carrying the cast sump, was used to close off the lower end of the engine block which gave the bottom end great strength.
The five-bearing crankshaft itself was made from spheroidal graphite cast iron and is extremely strong. A new, Jaguar patented, split coolant flow, from the water pump, delivered 50 per cent of the coolant into a gallery, bypassing the bores, to the cylinder heads at the rear of the engine.
This then mixed with the remaining 50 per cent of the coolant to cool the cylinder heads. Sign up to get the latest performance and luxury automotive news, delivered to your inbox daily! I agree to receive emails from Motor Authority. I understand that I can unsubscribe at any time. Privacy Policy. Contribute: Send us a tip Contact the editor. People who read this, also read: Porsche conducts internal investigation into potential emissions cheating for gas engines Spyker saved by new investors Preview: Volkswagen ID.
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