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Please consider these pages where created 10 years ago and are for Historic Information Purposes Only. For current stock, prices and information please visit our V8 Engine and Component listings in our online shop.

3.9 to 4.6 conversions & Injection upgrades

4.6ltr V8 New V8 high torque conversion from 3.5, 3.9 4.2.
ECU modifications & optimisation details (re-chipping)
RPi - Unleaded Cylinder Head Specifications

The following is advice and pricing to use your existing engine to achieve the beneficial torque and bhp increases of the new 4.6 generation of engines.

Suitable for brand new or very low mileage V8 Engines only, higher mileage engines may require some additional components, please enquire.

4.6ltr V8 'New' V8 'high torque' conversion from 3.5, 3.9 4.2.

With increasing speculation on the demise of leaded 4 star fuel, RPi can ensure your engine is 'Millennium Proof' because all of our engines now include unleaded heads as standard. Or we can supply them for your engine. Please note surcharges apply to all heads. œPOA


Stage 1 4.6 litre short engine (Brand new cross bolted) inc. Std cam, std lifters, & timing chain set and all std gaskets required for fitment œPOA
ECU re-chip and additional Modifications œPOA
K & N. Free flow filter œPOA
(Prices shown are in addition to above and previous stage's)
As above but with Piper 270/110 camshaft Vernier timing chain set and anti pump lifters œPOA

If you wish to retain high compression or increase it (this would not normally be of major importance), and use composite gaskets, it is not possible to remove (skim) enough from the face of the heads. So the solution would be to re-face the engine block or use the latest new 4.6 Rover heads (see above) which have only 28cc combustion chamber.

Labour rates will be dependant on whether we are supplying parts, they come pre-assembled, when fitted to an engine/transmission prior to fitting to the vehicle, or if we are removing and fitting on your behalf. Also, an allowance in full towards labour can be made if we are retaining a new or low mileage (tested) engine.

Trade discounts for quantity orders can be arranged.

injection injection injection
Extensively ported manifold & shortened trumpets Big throttle body plenum 70 - 73mm Close up view of the shortened & polished trumpets
injection injection injection
Modified & ported injection manifold (top view) Flowed, shortened & polished trumpets (top view) Extensively ported & flowed injection manifold ports (intake ports)

We have a range of Carbon fibre intake options available, single, twin and tripple throttle bodeis are availble and full details can be found here.

ECU Modifications & optimisation details (re-chipping)

The standard internal settings and fuel map of your ECU are like most manufacturer's parts built to a compromise, trying to cope with all climates world wide and all types of vehicle usage. This provides the opportunity for many enhancements to your vehicle's economy, performance and efficiency, but only if your ECU is re-chipped by a specialist and tailored to your engine's and vehicle's individual requirements.

Re-chipping should be treated as essential for large capacity or performance upgrades when made to the 3.9 & 4.2 (hot wire) type engine. Apart from the obvious need to re-chip your ECU when increasing engine capacity, the following are some of the superb advantages obtainable:

Engine Temperature Map Decreased for cold and warm-up fuelling to reduce flooding and fuel wastage
Throttle Response Adjusted to gain quicker throttle response
Airflow Meter Scaling Vital for good driveability and fuel economy, especially on large capacity engines Allows correct control of part throttle fuelling
Re-profiled Fuel Map Provides good fuel economy on part throttle, and allows engine to rev more freely, (standard profile reduces fuelling heavily after 4000rpm)
Idle Speed Lifted to give smoother idle
Throttle over-run braking Throttle over-run braking
Removal of road speed limit Standard 113mph road speed limit removed (Range Rover only)
Cranking Fuel delay Reduced risk of flooding, starting delay to allow oil pressure to build before starting
Separate manual and automatic versions available for optimum idle-speed control and stability. Non catalyst, catalytic converter and dual tune versions also available.

For all vehicles, the standard Rover ECU is programmed to offer a limited level of all of the above computations, however, the factory setting for this ECU is for a one-and-half tonne vehicle with 4wd and poor aerodynamics, although your application may be for a far different vehicle, you should enjoy a fair level of compliance. However, you will realise some very surprising results are obtainable, even if the ECU re-chipping is the only improvement you make to your V8 engine.

3.9/4.2 to 4.6 conversion chip only (for self fitment) œPOA
Optimax 3.9 chip, 10% - 15% increase in power andefficency on all std 3.9 engines œPOA

links to other component pages
[ Back to: V8 engine and component information and pricing ] [ Carburation & fuel Injection ] [ Electrical ]
[ Transmission 2wd & 4wd ] [ Suspension, Handling,Tyres, Wheels & Brakes ] [ Stainless & Mildsteel Exhaust systems ]

Prices do not include local EU.Tax.(VAT).
Prices & stock are subject to change without notice. Information and advice, as always, is free.

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Tel +44 (0)1603 891209 Fax +44 (0)1603 890330

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