MGB V8 Roadster Supersports (part 1)
MGB V8 ROADSTER SUPERSPORTS
A classic sportscar with modern Power, Handling and Performance
With the abundance of power that the Rover V8 engine provides coupled with classic and timeless styling, the MGB Roadster provides the ideal basis for an all steel, British sportscar, built to your personal specification, and with the potential to outperform many modern production sportscars.
Over the next few months we will demonstrate that building an MGB V8 Roadster to your own specification is both practical and achievable, by building a 265 bhp 4.6 litre V8 supercar, with excellent handling and innovative styling in the body and the interior. To get the project underway we took one of the new MGOC (Spares) specification V8 roadster shells, and delivered it to MGOC (Workshop) to prepare and paint in Brilliant Silver. The result is a shell ready to receive a high specification of Engine, Drive Train, Suspension, Brakes and Interior Trim – all of which are readily available to install using normal workshop tools and sound DIY mechanical skills. If your preference is for a V8 GT, this shell is also available with the same modifications incorporated. As the building of the car progresses we will take you through the each stage, giving you the options available for each area of the car, and an indication of the time taken to build. In this first installment we go through the donor car you will need and the new bodyshell, showing the modification included to allow straightforward fitment of the V8 specification components.
You will need an MGB Roadster to act as a donor car, and the best one to choose is an early rubber bumper model, which has the collapsible steering column and correct dashboard and instrumentation size for the car. These are also one of the least valuable cars, and an ideal MOT failure vehicle could be purchased for between £500 and £750. This will give the new car its identity, although the extent to which you re-use components from the donor car will ultimately be determined by your own specification.
The availability of new parts is so high that if you really wanted everything new, it would only be the windscreen frame and possibly the rear axle casing that would have to be re-used. Having taken all the components you need from the donor, any remaining parts that are not required for the project can ultimately be sold as core items for reconditioning. By using this method you could strip the donor car down to a bodyshell and recover a large part if not all of its original purchase price.
A RV8 TUBULAR MANIFOLD – Holes cut and reinforcement plates fixed in flitch panels as per RV8 to allow escape of RV8 manifolds to the underside.  |
B OIL FILTER MOUNTING – is situated on the right hand side behind the radiator diaphragm as per the factory V8, to mount the remote oil filter housing. The regulator bracket is omitted from the right hand valance. |
| C STEERING COLUMN – The specification provides for the use of the late Rubber Bumper steering column. All mounting brackets and apertures necessary are provided to accommodate this. | D GEARBOX TUNNEL – is modified by the inclusion of a turret built into the top of the transmission tunnel under the reinforcement brace, which connects the tunnel to the bulkhead. This provides sufficient clearance to allow Rover LT77 and R380 5 speed gearboxes to be installed.  |
E TWIN REAR SILENCERS – The rear valance was modified to provide an extra exhaust tailpipe cutaway on the offside at the same relative distance spacing as the original. This will allow fitment of a twin silencers system from cylinder heads to tailpipes giving the classic V8 exhaust “burble”, whilst at the same time showing more than a hint of the performance potential.  |
F FUEL TANK FILLER BLANKING – The filler hole in the boot floor was blanked off using a welded circular plate, as a new narrow fuel tank will be used to give sufficient clearance for the second exhaust pipe to be sited adequately. A new filler hole will be formed when the new tank is offered into position. |
| G REAR WING FITMENT In order to allow the widest possible fitment of wheels and tyres, the rear wings are fitted at their widest possible tolerance on the jig. | H REAR VALANCE – is Chrome Bumper MGB |
I ANTI-TRAMP BAR – Reinforced Sections on which anti-tramp bars can be fitted are bolted to the existing Chrome Bumper spring mounts, and the strengthening sections which are welded into place, extend forward to meet the central crossmember. The rear spring mounts are of the Chrome Bumper spec. to give a lower centre of gravity. The Anti -Tramp Bar fixings allow the RV8 Anti- Tramp Bars, Lower Spring Mounting Plates, and Shock Absorber Lower Mounting Spigots, to bolt directly into place with no further modification required.  |
J REAR WHEEL ARCH LIP EDGE REMOVAL – With power and performance in mind from the outset, it is clear that fitting the widest possible wheels and tyres will be a priority. A 3mm gained each side can be made by folding the rear wheel arch lips under whilst at the same time dressing out the wheel arch slightly to give a further 2mm, a total of 5mm per side overall. |
| K GEARBOX CROSSMEMBER MOUNTING – Extra holes are fitted each side on the chassis legs to which the gearbox crossmember mounts, and these are equidistant to the spacing of the originals. The threaded plates in each are extended to align with these. The purpose of this modification is to allow easy fitment of different types of 5 speed gearboxes. | L FRONT AND REAR WINGS – are standard Chrome Bumper MGB Roadster. |
| M BRAKE MASTER CYLINDER – The body is modified at the drivers side inner wing / bulkhead area to accept the type of Brake Master Cylinder with the Brake Servo attached in line, as per the 1977/78 spec. | N FRONT VALANCE – is Chrome Bumper MGB Part No. HZA592 |
| O V8 BONNET LANDING PANEL – Fitted. | P FRONT BUMPER MOUNTS – for Rubber Bumper are omitted and replaced with Chrome Bumper chassis extensions and side members fitted with two bumper iron nuts to allow fitment of the standard Chrome Bumper bumper irons |
| BONNET LOUVRES – A new design of slotted bonnet louvres has been incorporated to give a further hint at the performance potential, whilst at the same time helping with under bonnet cooling. | BONNET CROSS BRACE – The cross brace reinforcement section is moved 100mm further forward along the bonnet to allow extra clearance for when Holley or Webber carburetors are used. |
| SHELL BASE – is a Rubber Bumper MGB Roadster. This already provides the correct position for the engine mountings and the shape and contour of the front inner wings is correct to allow the manifolding to position correctly. | V8 RADIATOR DUCT – The Rubber Bumper V8 Radiator Duct is fitted |
When considering the new bodyshell, it is worth going over the specification in detail to fully appreciate the degree to which a wide range of component specifications can be installed to fittings already included, simplifying and reducing the number of hours needed to build the car.
This unique bodyshell is built to MGOC (Spares) own specification by British Motor Heritage Ltd and the main features are detailed as illustrated.
With the body prepared and painted in Brilliant Silver, the build up is ready to begin, and next month we will look at the options of engines and gearbox available.
MGOC Spares Spec.V8 Roadster Bodyshell £3,850.00
Preparation and Painting by MGOC Workshop £1,875.00
Further styling mods. as detailed £485.00
For details of the components used in this project telephone MGOC Spares on (01954) 230928
N.B. Bodyshell supplied complete with bonnet, boot and doors fitted
There are numerous other minor modifications additional to the above, which improve or simplify the build up of the car, which need not be detailed here. However, as special interest features for the project car some further bodywork modifications were carried out in the workshop prior to painting, to provide the finished car with some very distinctive styling features. These are bonnet louvres, fuel tank filler blanking, rear wheel arch lip edge removal, and rear valance twin rear silencers modification. (N.B These and other mods can be included at extra cost.)