A favourite since it was created in the 1960s, it is still the engine of choice for many JE Motorworks customers to this day.
The classic Rover V8 engine was an important feature of the UK motoring scene for more than three decades. Developed by Buick in late 1950s America, Rover developed it for applications from sportscars to luxury four-wheel drive SUVs. JE Motorworks has been involved with the Rover V8 for the last 50 years, and continues to develop new ideas for the engine today.
There were three main versions of the engine, each of which had many variants. The earliest 3.5 litre units were produced until 1976 and the launch of the Rover SD1. Pre-SD1 units have smaller valves in the cylinder head and are based on noticeably lighter castings.
Until 1994, the 3.5 litre engine had larger valves and heavier main castings. Material was added in strategic places to make the block stiffer and allow for bigger cylinder head ports. JE Motorworks was instrumental in developing the 3.9 litre version in 1989, and a 4.2 litre version in 1992, both of which Rover adopted into their production offering.
From 1994 Rover made some big changes to the engine design. The crankshaft dimensions were strengthened significantly, the cylinder blocks gained more weight to increase stiffness further, and the engine became available in 4.0 litre and 4.6 litre capacities. The earlier version continued for a short time alongside the new version, largely for use in the last of the Range Rover Classic and the first series of Discovery.
In Land Rover production terms, the last use of the 4.0/4.6 engine was in the Discovery 2 model phased out in 2004, but the engine was made in small quantities for a little longer, for use in specialist applications.
Rebuilding and optimising one of the early Pre-SD1 units is worthwhile if you need to keep your vehicle very genuine and original for racing regulations or ‘concours’ appearance. Most of JE’s work on Rover V8 engines involves tuning and improving for more torque and power, so we more often work on the two later types of engine.
Due to its ready availability many people start a project with a 4.6 engine; unless a larger capacity engine is vital, it’s a satisfactory power unit. We usually build them as either 3.9 or 4.5 litres, using an 80mm crank shaft with the 94mm bore. They can be built to use high rpm if necessary, but if the project involves retaining SU or Stromberg carburettors power will be limited anyway, making those extra cubic centimetres less important.
Where the larger engine is required, we often build a 4.8 litre version. With high-mileage engines it’s often necessary to reline the V8 cylinder block with new iron cylinder liners, so we put in liners for 96mm bore rather than 94mm. 96mm bore with 82mm stroke gives 4748cc, which we call 4.8. We also build 5.0 litre using a longer stroke of 86.3mm, giving 4997cc.
We often build a modernised 4.8 with the Thor inlet manifold in the most recent Defenders with electronic throttle actuation. This is frequently installed with an electronically controlled automatic gearbox. It gives a very wide torque spread with peaks at roughly 2500 and 4500 rpm, so low speed output is much better, making it very appropriate for 4x4s.
We build the engine with a motorised throttle, modern injectors, and a new, revised cam profile. The inlet manifold is gas-flowed using the ‘extrude-hone’ process, and the cylinder-head ports are CNC machined then finished by hand. With larger valves and everything very carefully balanced, we get 275 bhp and 430 Nm. As mentioned, the torque output is above 400 Nm over a wide range of the engine rpm.
Cylinder blocks and short engines produced by JE Motorworks are very carefully prepared. Units, as a minimum, have all these operations completed during the build:
All JE cylinder heads are thoroughly cleaned, and the oil and water passages carefully checked. If necessary faces are machined (skimmed) and the eight combustion chambers in a pair of heads are measured, modified, and balanced to to give equal compression ratio across the engine. New valve seats are fitted where necessary, and all seats cut to the same height and blended into the combustion chamber surface shape. In addition:
All but standard heads require significant material removal to improve gas-flow. The bulk of this material is removed by CNC machine to provide a consistent shape. All work is hand-finished tio achieve precise matching and blending of surfaces.
There have been three different basic inlet manifold arrangements for the Rover V8, with some variations:
We offer many different ways to improve gas-flow in these manifolds. For more complicated shapes the ultimate solution is the extrude-hone process. We also use die-grinding tools to carefully remove material where the port shape allows access. We install larger throttles where appropriate, and for the Lucas/GEMS type, we offer the famous twin-throttle plenum chamber which gives very good power at higher rpm.
There are many different camshaft profiles available for the Rover engine. JE continue to offer our very successful ‘101’ profile for fast road use in moderately tuned engines. We have other JE-designed profiles suitable for fuel injected engines in heavier cars and 4x4s. For road use of sports cars and racing we have other cams with more lift and duration.
Using Land Rover rocker shafts for speeds between 6000 and 6800 rpm, we recommend our reinforced billet steel end supports. Full race roller rocker shafts, using needle roller bearings and improved shaft supports, are also available.
JE continues to produce the large-bore cast-iron exhaust manifold, suitable for engines producing up to 320 bhp. Alternative tubular manifolds can be obtained for special installations.
JE Motorworks can supply many good solutions for engine installations, including fuel injection ECU, wiring harness, carburettors, catalysts, ignition coil(s), distributor, leads, induction air filter(s), clutch, flywheel, alternator, and starter.
The Rover V8 engine is popular for kit car building and re-engineering work on classic cars. Lightweight with excellent torque output, it is a straightforward choice for low-volume and home-build projects.
JE Motorworks has updated the engineering of the Rover engine to produce two very practical and fast versions for easy installation and great performance. They use electronic fuel injection with very accurate adjustments to give excellent power, driveability, and economy. Built into the induction system so that it looks exactly like the classic 4-barrel carburettor inlet, it gives the right under-bonnet image for a classic sportscar or fast saloon.
We call these engines the 289 and 302; the true capacities are 4748cc and 4997cc (or 290 and 305ci). Reminiscent of the classic Ford Windsor V but lighter, it is available with modern technology and gearbox options. We have designed a camshaft to give easy starting and a stable idle, while having plenty of torque and top-end power. We can fit other camshafts to release more power, but the idling and ease of use in traffic can be compromised.
Several years ago Rover fitted its own petrol V8 engine in Defenders. The Rover V8 is compact, lightweight, very torquey, and represents the ‘authentic’ petrol power unit for the car. JE can convert most Defenders to run the V8 again, using either fuel injection or carburettors. Our most sophisticated engine, which we often install in the recent 2.4 and 2.2 Tdci Defenders, is a modernised 4.8 litre V8 (474cc) with the high-torque Thor inlet manifold.
This revised 4.8 litre has fully electronic throttle actuation to optimise driveability, often installed with an electronically controlled automatic gearbox. For the ultimate statement of the Rover engine, we can increase the engine to 5.0 litres (4,997 cc), and use even larger inlet valves. Maximum torque increases to 450 Nm, and maximum power to 285 bhp.