Callaway 4.6 HSE Range Rover Technical Specifications



1999 Model Year Callaway 4.6 HSE Range Rover

The following information describes the technical specification for 220 Callaway 4.6 HSE Range Rovers. This information should be used for all press-related questions and also for updating all technical publications within Land Rover North America and Rover Group. This specification is only available in the USA. The vehicle’s major unit areas describe the specification areas where a change has occurred.

The 4.6-L based Callaway Range Rover specification was developed to specifically improve upon performance within the drive train and deliver a visually different 4.6 HSE.

The specification delivers 240 bhp at 5,000 rpm and peak torque of 285 lb-ft at 3,500 rpm. The specification was engineered to deliver an improved 0-60 mph time and a reduced quarter mile elapsed time, as compared to current production 4.6L Range Rovers. All of the changes described hereafter were engineered as a system to deliver the stated goals.

The “short-block” of the engine is unchanged in design and manufacture. Short-blocks used for the 4.6 LE Callaway engines are uniquely labeled with a 9.60:1 compression ratio marking.

Compression Ratio
The compression ratio (CR) for the Callaway 4.6L engine is 9.60:1. This is an increase of 0.25 points, up from the O.E. CR of 9.35:1. The increase was achieved by a modification to the cylinder heads.

Cylinder Heads
The cylinder heads have been modified to improve the airflow into and out of the combustion chambers. The airflow through the exhaust port has been increased by 15% while the intake ports have a 17% greater flow rate at the same test pressures.

Valve Seats
The intake and exhaust valve seat geometry has been modified to allow enhanced gas flow into the combustion chamber. This has changed the geometry on the cut used to form the valve seat surface.

Valve Guides
The valve guides used on the LE Callaway 4.6L heads have been tapered on the combustion chamber end of the guide The taper has been added to improve the airflow around the valve guide in the intake and exhaust ports.

Rocker Shaft Pedestal Plates
Each Callaway cylinder head has a pair of rocker shaft pedestal plates permanently attached to the head. These plates are used to correct the valve train geometry after the cylinder head fire faces have been machined.

Inlet Manifold
The inlet manifold has been port matched and the flange surfaces matched to the cylinder heads.

Inlet Manifold Gasket
The inlet manifold gasket has been port matched to align with the cylinder head and lower inlet manifold castings.

Inlet Manifold Gasket Front Valley Clamp
The front valley gasket clamp has been changed to accommodate the heater hose positioning on the bottom front of the Callaway manifold. It is unique to the Callaway 4.6L V8.

Ram Pipe Housing
The ram pipe housing has been modified by shortening the ram pipe tube lengths. The intake runner lengths have been tuned to deliver the increased power and torque in the appropriate areas of the engine’s speed range.

Upper Plenum
The upper plenum assembly has been modified to deliver increased airflow rates to the engine. The diameters of the throttle plate and bore have been increased to 2.800″ (71mm), an increase from the standard production size of 65mm.

Air Inlet Tube
The air inlet tube has been replaced with a larger diameter carbon fiber inlet tube to match the the larger throttle bore in the plenum. The carbon fiber inlet tube delivers improved airflow characteristics and is isolated on each end with flexible silicone rubber couplings.

Air Cleaner Box Assembly
The air cleaner box base has been modified to increase the airflow rate into the air cleaner box assembly. The top portion of the air cleaner box has not been modified.

Air Filter Element
A high-flow panel style air filter element is utilized inside the air cleaner box.

Engine Management System (GEMS)
The GEMS ECU incorporates a unique calibration to support the mechanical changes to the Callaway engine. The engine control system fuel injection and spark advance parameters have been optimized to benefit from the mechanical changes made to the engine.


Automatic Transmission
The automatic transmission used in the Callaway 4.6 HSE Range Rover is an improved four-speed automatic utilizing a different specification torque converter.

Automatic Transmission Control Unit (TCU)
The transmission control unit (TCU) has been re-calibrated to take advantage of the increased torque and power from the engine. The shift points in “NORMAL” and “SPORT” modes have been optimized to match the engine’s power throughout the engine speed range while maintaining excellent gearshift quality.

Transfer Gearbox
The electronic shift transfer gearbox has a new ratio sprocket set and chain. The resulting new ratios provide a high range ratio of 1.294:1, and a low range ratio of 3.481:1. The ratio change improves acceleration performance in high range while also providing improved off-road “crawl” performance and coast down rates in low range.

Front Axle Shafts
The front axle shafts used on the Callaway 4.6 HSE have been strengthened to withstand the increased torque to the front wheels from the engine and transmission changes. A material change in the axles ensures durability will be maintained for the front axle half shafts.

Front Axle Differential
The Callaway 4.6 HSE front axle differential utilizes a four-pin differential section to accommodate the increased torque transferred through the drive train. The four-pin differential replaces the two-pin unit used on standard production Range Rover front axles.


Exhaust System
The Callaway 4.6HSE Range Rover utilizes a reduced backpressure exhaust system. Changes to the exhaust system have been made rearward of the catalyst “Y” pipe assembly. The exhaust system backpressure has been reduced by 43 percent. The interior sound level in the passenger cabin is virtually unchanged.

Center Silencer
The center silencer provides reduced backpressure and is constructed from stainless steel.

Tail Pipes
A twin tail pipe system has been selected to provide a performance look and sound for the Callaway 4.6 HSE. The straight exit twin outlets are accented by T304 stainless steel resonator tips to visually differentiate the Callaway 4.6 HSE from other Range

The exterior of the Callaway 4.6 HSE Range Rover is accented with painted body color components. The exterior components painted to match the body color are:

– Front Bumper
– Front Grill
– Left and Right Headlamp Finishers
– Left and Right Door Mirror Casings
– Rear Bumper with Exhaust Tip Openings

18 inch 5-spoke “PROLINE” alloy wheels accent the exterior painted body color components.

Body Colors Available: Niagara Gray, Epsom Green and Rutland Red

The Vehicle is badged with “CALLAWAY” on the upper engine plenum, and on the lower rear tailgate.