From the foregoing, it is quite possible to produce engines, which provide a substantial increase in power and torque simply by modifying engines to an established design specification. As a general rule, therefore our standard fast road engine is basically common with the V8 X-pack, the X-pack engine being a later development of the Vantage engine that went into production in 1977.

With lightweight low friction pistons, electronic ignition, revised camshaft timing and porting, these engines develop around 430 bhp and 350 to 370 ft lbs of torque totally reliably and with excellent flexibility and smoothness.

An increase to 6 litres can be readily incorporated that provides a sizeable increment of additional torque over the entire engine speed range. This makes for exceedingly rapid and flexible performance. The main fast road engine options are therefore:

• 5.3 litres standard Vantage specification – nominally 380 bhp
• 5.3 litre standard Vantage X-Pack specification – nominally 430 bhp
• 6.0 litre standard spec – nominally 380 plus 20% increase in torque from 1500 to 5000 rpm
• 6.0 litre X Pack nominally 460 to 470 bhp plus additional 20% torque from 1500 to 5000 rpm

The fast road options above retain the original stroke of the engine, and because of that, it is possible to retain the original crankshaft and con rods and thereby, limit the costs of the upgrade. However, the decision to retain or replace these depends critically on condition. A new crank and rods may be desirable with the 6 litre option.

A simultaneous engine overhaul, which would be desirable anyway, will involve new liners and pistons. All of the fast road options require extensive changes to the cylinder heads, from enlarged valve seats, valves, springs and cam followers to gas flowing of the inlet and exhaust ports and new camshafts. New lightweight forged high compression pistons are also required.

The standard Vantage carburettor is the Weber 48 IDF with Vantage standard inlet manifolds. A set of enlarged bore exhausts manifolds are also required to compliment changes to the cylinder head.