Electrical System
The standard twin 6 volt or single large 12 volt batteries as fitted to the 1800 MGB are adequate for the V8 application.
The amount of alteration to the wiring loom, compared to many other conversions is quite straight toward. The starter motor is in the same position with similar connections as is the alternator. However clearance between the rear of the alternater and the rocker cover is limited which may require the plug to be modified or individual insulated connectors being used. Wiring will have to be extended to the new position for the ignition system. On late models a second cooling fan motor will have to he wired in parallel with a suitable relay and a Kenlowe control and on the earlier models wiring will have to be provided for both motors and controls.
Because of the twin cooling fans, an alternator with an output of 45 amps or more is needed . This is normally mounted in front of the offside rocker cover and this unit has to be quite short and of a small diameter. The normal B alternator is not suitable for this application, and the standard MGB GT V8 alternator or equivalent should be used. The new Valeo alternator that we supply comes less the pulley and fan however these items can be used from the original 1800 alternator. The standard tachometer will need modifying for use with the 8 cylinder engine. Some owners have managed to mount the movement of the SD1 tacho in the MGB case alternatively your tacho can be sent to:

Speedy Cables (London) Ltd
The Mews
St Paul Street
Islington
London NI 7BU
Telephone 071 226 9228

Who will carry out the mod, they will also carry out any speedometer modifications should this be needed.

If a conventional early Rover points type distributor is used, a ballasted coil should be used along with a suitable ballast resistor, later MGBs have this already in the loom. The coil should be mounted on the nearside radiator mounting plate, adjacent to the header tank, SD1 V8's used electronic ignition. Early models used the Opus system and later vehicles used the Constant energy system either of these systems work well but it is best to obtain any associated components (i.e. ballast resistor, amplifier, wiring, coil) from the donor vehicle as these components are quite expensive. With high mileage Rover distributors the electronics may cause problems and replacement components are extremely costly however Luminition can provide some excellent alternatives at reasonable cost. When fitted in its normal position the vacuum advance unit, when viewed from tile front of the engine is at approximately 8 o'clock relative to the distributor body, this would obstruct the top hose so the distributor will have to be rotated so that it is at 3 o'clock and the HT leads retimed.
With the early points ignition the drive on the bottom of the distributor for the oil pump is male and on all the latter electronic units it is female making it rather difficult to swap these units. The standard 1800 electric fuel pump seems to cope quite adequately with the V8 engine in standard tune and this unit was used in the production GT V8, The pre-SD1 engines were fitted with a manual pump and this can be used if preferred. It is worthwhile fitting a fuel filter between the pump and the carburation. If you are modifying the engine output, you may find it beneficial to fit an uprated pump some of these produce a high pressure so a pressure regulator may be required.



V8 Conversion Project

Overview of Project

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