At ACR you will find a range of products and services for the Land Rover Defender, Series, Range Rover, Range Rover Sport and Discovery models, covering the engine and related components. Our range includes cylinder heads, cylinder blocks, short engines, 3/4 engines, stripped engines, complete engines and ancillary parts such as starters and alternators.
Owners of series Land Rovers and early 90 / 110 models with the 4 cylinder petrol engine who require more power please look at the 4 cylinder petrol performance tuning page.
For our range of performance engines for vehicles with the Rover V8 or the Jaguar derived V8 look here.
Performance Tuning
The Power Plus © performance tuning system has been developed to provide owners of classic Series 11, 11a, 111 and 90 / 110 Land Rovers fitted with the 2.25 / 2.5 petrol unit with extra power and efficiency. The system has been used on every continent and in every situation Land Rovers may be found. The Power Plus © system offers levels of extra performance to suit the application and budget of each requirement without compromising the legendary reliability of the Land Rover 4 cylinder unit.
The Power Plus © tuning system allows the engine to produce more torque especially in the low to mid range. This results in faster acceleration, less gear changing and the ability to maintain speed on gradients. This makes the Land Rover easier and safer to drive both on and off the road.
The 2286cc petrol engine was developed for the Series 11 Land Rover, launched in 1958. It featured many common components and dimensions to the diesel version of this engine. This enabled Land Rover to produce both versions of the engine with the same machine tools and production line. As a result the petrol version was considerably over engineered for its 115 FtLb of torque and 67 BHP.
Over the years remarkably little changed. 1980 Saw the introduction of 5 main bearing crankshafts, and 1985 a longer throw crank shaft raised capacity to 2495cc The petrol engine continued in production until 1992, when Land Rover deleted the petrol unit from its product range. The diesel version continued in the form of the 200 and later the 300 TDI unit. Although Land Rover no longer manufacture the 4 cylinder engine, it is still in production in Brazil. Developed further, now with a capacity of 2.8 litres and used in the South American built Ford Ranger Pick up. From the engine tuners point of view the 2.25 / 2.5 engine is ideal. The cylinder head design was modern for the 1950s and material thickness is generous, allowing the tuner to raise compression ratios and reshape the ports to give great increases in air flow. Manifolding and carburation is restrictive, and camshaft profile is very mild indeed. This, combined with an exceptionally robust design, allows massive power gains without the risk of shortening the life or reliability of the unit.
Cylinder Heads
The cylinder head is the first thing to consider when tuning the 4 cylinder unit, as big gains can be made from this change alone.
When considering performance cylinder heads it is worth specifying 9:1 compression as this raises overall efficiency, yet is still suitable for standard (95RON) lead free fuel.
The airflow efficiency of the inlet and exhaust ports has a direct bearing on engine torque and power. ACR have invested considerable time and resources to develop, using airflow and dynamometer test techniques, the most efficient port designs, with the highest airflow rates possible, yet retain compact port areas, vital to low speed torque and fuel efficiency.
These ultimate port profiles are, on our Stage 2.1 cylinder heads re-created (uniquely in this field) using advanced CNC machining technology on every production item we produce. This completely eliminates all hand working of ports. Solid bronze valve guides, and further CNC machining of valve seats all add up to produce the most advanced cylinder heads available.
All our performance heads feature solid bronze valve guides, suitable for lead free fuel. Stage 2.1 heads are specified with 9:1 compression as standard, with the choice of 8:1 or 9:1 on Stage 1 units. 9:1 units are suitable for use with regular 95RON lead free fuel. The 9:1 compression improves thermal efficiency, and is strongly recommended. It is particularly useful with LPG fuel.
All our cylinder heads are supplied built up, ready to fit and with a decoke gasket set provided. Available on an exchange or outright sale basis.
Consider the Stage 2.1 Cylinder Head if using with other Power Plus © products
Stage 1 8:1 cr + 6 BHP on standard engine
Stage 1 9:1 cr + 6-8 BHP on standard engine
Stage 2.1 9:1 cr + 15 BHP on standard engine
Power Plus © SU Carb System
This system is supplied in two formats, one for leaf sprung Land Rovers and one for coil sprung vehicles. The leaf sprung kit consists of the new intake manifold casting, HS6 SU carburettor, K+N air filter and all fixings, gaskets and fitting instructions. A free flow exhaust silencer is included
( also available separately ) Please specify if 88″ or 109″ wheel base. The carb is ready jetted to suit, with a thicker, lean calibration needle option available for high altitude.
Coil sprung Land Rovers have a more efficient exhaust so do not require the silencer. They do however need a modified exhaust manifold, so this is included instead.
For LPG fuel users we can supply the correct sized adapter for the SU carb.
Power Plus © carb + Stage 2 Head + 30 BHP over standard.
Power Plus © Camshaft
This camshaft has been developed to improve torque output. There is more torque at every point in the rev range. The camshaft is manufactured from new (not a re-profile) and has a higher rate of valve acceleration and lift. The camshaft requires “timing in” to function correctly (instructions included). The last of the 2.25 and 2.5 engines will need an early 6 way chainwheel to position it correctly. Tappets are of the roller design. If any doubt as to their condition, we stock new heavy duty items.
Power Plus © Camshaft + SU carb + Stage 2 Head + 43 BHP over standard.
Power Plus © Tubular Exhaust Manifold
This tubular manifold is of the 4:1 design. and connects to the standard inter pipe. It includes fixings and gasket. Users report a MPG improvement as well as power increase. We can modify this to fit coil sprung models too.
Power Plus © 2.8 Engine
This unit is based on the 5 main bearing 2.25 or the 2.5 engine. It features 95 x 97 mm bore / stroke and is supplied as a stripped unit with the Stage 2 Head, Power Plus © SU carb and Camshaft. Where it replace a 3 main bearing unit the parts (Fly wheel etc.) required to convert can be added. For customers who have already some or all of the Power Plus © system installed on their Land Rover, in most cases this can be re used.
Power Plus © 2.8 Stripped Engine with Stage2 Head SU carb and Camshaft produces the following output: 177 FtLb @ 2300 RPM 117 BHP @ 4100 RPM.
Lumenition Magnetronic Ignition
Cost effective system to replace the points in a Lucas distributor. Useful with higher compression ratios and LPG fuel.
Distributorless Ignition
This is the ultimate ignition for the Land Rover engine. The mechanical distributor is removed and replaced with a core plug to seal the redundant hole. The spark is provided by a waterproof coil pack. This is controlled by a micro processor which picks up a load signal from a manifold mounted pressure sensor, and crank shaft speed and position from a sensor mounted on the fly wheel housing which reads the 36-1 teeth machined on the fly wheel. The engine management system is user programmable to set the correct spark timing for every load and RPM. This results in better part throttle power and economy. The system does much more, as it has programmable rev limit, shift light and many other features. We provide the system pre-mapped when specified with an engine, User mapping is possible with a laptop computer and it is even possible to data log the engines performance and sensor parameters whist running.
Package Deals
We can build an engine or Power Plus © package to your specification. Popular packages include the following:
3 main bearing 2.25 remanufactured unit with Stage 2 Head, Power Plus © Camshaft, and SU carb.
Stage 2 Head, SU carb, Power Plus © Camshaft and 4:1 Tubular Manifold.
Remanufactured Engines
ACR have a modern fully equipped machine shop with the latest CNC vertical machining and turning centres, enabling components to be machined faster, more accurately and with better surface finishes. For example computer controlled measuring systems built into our machine tools allow ACR to reference cylinder blocks prior to boring to the original blue print specifications, then bore the cylinders automatically and individually to provide the correct running clearance and surface finish for each piston.
All processes are carried out in house to ensure complete control of every aspect of remanufacture. Engines are assembled in a clean, controlled and dust free environment using parts chosen for their reliability and performance. This provides customers with an engine which will give smoother running, better performance, reduced emissions and a long trouble free life.
Engines are available in several formats as detailed below for each range. Ancillaries such as clutches, starters and distributors can be added as extras as required. In most cases engines can be specified with our performance tuning components from a mild Stage 1 Cylinder Head to a full motorsport unit. Please refer to our performance tuning page for more details.
Land Rover Series, Defender, Discovery and Range Rover 4 cylinder 2.25 and 2.5 Petrol and Diesel engine range.
ACRs range of 4 cylinder engines cover the 2.25 and 2.5 Petrol, the 2.25 and 2.5 Diesel, 2.5 Turbo Diesel and the 200 and 300 TDI Diesels. All Petrol’s are suitable for lead free fuels and LPG gas.
3/4 engine – Includes cylinder block, crankshaft, pistons, connecting rods, camshaft, tappets, oil pump, timing chain (where fitted ),front cover, front pulley, sump etc. Does not include cylinder head.
Stripped engine – As 3/4 unit but with cylinder head, valve gear, rocket cover, first fill running in oil and gaskets to mount ancillaries.
Engine will run once ancillaries are added. An ideal solution for replacing a worn or damaged engine.
Complete engine – Stripped engine with ancillaries up to a turn key engine.
Range Rover 3.9 4.2 4.0 4.6 V8 engine range
ACRs range of rover V8 engines incorporate our own unique heavy duty top hat flange liner ystem to eliminate problems caused by the notorious cracking or porosity which affects the original Land Rover design. All ACR cylinder blocks are CNC machined and fitted with a unique liner sealing arrangement, giving a total, permanent solution. Our stripped engine package is especially tailored to suit the needs of the owner and installer who requires a complete easy to fit package, we include the all important front cover and oil pump along with the sump and rocker covers in this specification. Earlier 3.5 versions for Defender, Range Rover Classic, and Classic Rover cars available to special order.
Product range most versions available ex stock.
Bare block – Fully machined with new cam bearings, core plugs etc. Does not include crankshaft, pistons etc.
Bare block and pistons – set of 8 pistons complete with rings, matched to suit block.
Short engine – Includes crankshaft, pistons, connecting rods, camshaft, timing chain and chainwheels only
3/4 engine – As short engine but includes sump, front cover with oil pump, front pulley and tappets. No cylinder heads.
Stripped engine – This package includes cylinder heads, rocker shafts, rocker covers, front cover with oil pump, front pulley, sump etc.
First fill running in oil, gaskets for mounting ancillaries and manifolds etc.
Complete engine – Stripped engine with ancillaries up to a turnkey unit.
Range Rover, Range Rover sport, Discovery and Jaguar V8 Petrol engine range
ACRs Range of the Jaguar derived V8 petrol engines includes the 4.2 supercharged and 4.4 naturally aspirated as used in the 2005 year onwards models. Our range includes some Jaguar XJ, XJR, XK, XKR and S type cars including early models with nikasil coated cylinders.
The Jaguar engine uses selective fit assembly techniques for achieving the corect running clearances of many components throughout the engine, effectively limiting the prospect of DIY and general motor trade repair and assembly for many.
As fitting the engine in many cases a major undertaking requiring the body lifting from the chassis, a right first time solution is essential.
Bare block – Fully machined ready for assembly. State what cylinder size grade required.
Bare block and pistons – set of 8 pistons complete with rings, size matched to suit.
Short engine – Includes crankshaft, pistons and connecting rods
Stripped engine – This package includes cylinder heads, camshafts and followers, timing chains and tensioners, front cover and oil pump, front pulley, sump etc. First fill running in oil, gaskets for mounting ancillaries and manifolds etc.
Complete engine – Stripped engine with ancillaries up to a turnkey unit.
Cylinder Heads
ACR Ltd offer standard and performance Land Rover Cylinder Heads for Land Rover engines. They are available on an exchange or outright sale basis, and cover Land Rover 2.25 / 2.5 petrol and diesel, 200 / 300 TDI and V8 Rover engines.
Remanufactured units are processed entirely in house. Cylinder heads are stripped then internally and externally blast cleaned to bare castings. Cracked or porous cylinder heads are rejected and scrapped. Sound, clean castings then under-go a series of machining operations to the sealing surfaces and valve seatings. Worn or damaged threads are replaced with stainless steel inserts. All valve guides are replaced, and petrol cylinder heads converted to allow the use of lead free fuel. Iron cylinder heads receive an oil and heat resistant coating. All cylinder heads are then carefully built up with new valves and springs. Assembled cylinder heads are individually heat shrink wrapped to seal and preserve them until required for use.
Were applicable cylinder heads are available with performance improvements.