Merged image of a V8 engine, Sherman Tank,  Clementine the Cat, and my MGA in the Alpes

MGB V8 Conversion


The previous restoration

V8 engine

Engine lowering

Engine steady bar

Weber 500 carburetor

Twin pipe exhaust


Wheelarch modifications

Twin pipe system

R380 Gearbox

Gearlever remote

Gearbox mountings

Front suspension

Front suspension mods


4 link rear suspension

Setting up

4-link rear suspension

Panhard Rod

Coil Over Damper Mounting

Upper Arm Mounting

Rear Axle and Propshaft

Sound proofing

Door window frames

Interior sound proofing

Radio and speaker installation


Interior trim


V8 engine problems

Ride and ride heights

MGB V8 - An unusual conversion

These pages describe the build and modification of my MGB V8.

The car is no longer with me - it's gone to a good home up in Edinburgh and Richard is now doing the wheelspinning. I had built the car for regular high speed cross country trips, though these days I only seem to drive to the supermarket. It did manage a 14.6 second quarter mile at Santa Pod despite being really slow off the line. The following is the story of the restoration and alterations.

The car:

This is my MGB GT V8. I converted a 1970 GT with parts from a factory V8 that had been written off in an accident.

The original engine had been re-sleeved to 3.9 liters, and the liners sunk into the block after only 15,000 miles causing combustion gases to push all of the water out of the cooling system. I decided to make a few more modifications while the engine was out.

Restored MGB

More > | The previous restoration |


I bought the replacement engine second hand. It was built by RPI Engineering from a factory 3.9 block. The engine is fitted with stage 1 heads, Piper 270 camshaft, and a Weber 500cfm carburetor on an Edlebrock Performer manifold. The specification should be good for more than 200bhp. The engine came out of a Dakar kit car which is now fitted with a 5.7 Chevy.

I have installed the engine about 25mm lower than standard to avoid a bonnet bulge. I've also fitted an engine steady bar to protect the overloaded engine mountings.

Complete engine and gearbox out of car

More > | Engine lowering | - | Engine steady bar | - | Weber 500 carburetor |


My MGB used to be fitted with the usual tubular manifolds which were extremely bad for air flow and fouled the steering column. I designed larger diameter manifolds which exit through the inner wing (RV8 style).

The exhaust system is twin pipe with a balance pipe. I've fitted a pair of large silencers in the space where the leaf springs used to be (see rear suspension below).

STainless steel manifolds

More >| Manifolds | - | Wheelarch modifications |- | Twin pipe system |


The MGB had been fitted with the original MGB V8 gearbox which is known to be weak. I took the opportunity to fit a Rover R380 gearbox. The gearbox is based on the SD1 LT77 gearbox but is stronger.

I had to increase the transmission tunnel height to fit the gearbox, and move the gearbox mounting crossmember. I made my own remote selector mechanism to move the gear stick to the correct position and also to improve the gearchange quality.


More > | Gearlever remote | - | Gearbox mountings |

Front Suspension:

Lever arm dampers don't have quite enough damping for a high performance sportscar. Also they don't work for small wheel displacements and hence my MGB had a high sensitivity to steering nibble when the tyres were slightly out of balance.

I have designed my own conversion, similar to the RV8, where a Koni telescopic damper sits inside the original road spring.

Front Suspension

More > | Front suspension | - | Drawings |

Rear Suspension:

I opted for an SD1 live rear axle which needed to be shortened by about 12 inches to fit. The axle is mounted by upper and lower trailing links in order to control the fore-aft position of the axle and reduce torque steer. Lateral location is by Panhard rod.

I'm really pleased with the results. Torque steer has almost been eliminated, and the handling is much more predictable.

More > | Setting up | - | 4-link rear suspension | - | Panhard Rod | - | Coil Over Damper Mounting | - | Upper Arm Mounting | - | Rear Axle and Propshaft |


Many of the modifications on this car have had something to do with noise. My career is in automotive noise and vibration and I have become especially sensitive to noise in my own cars. My intention with the MGB was to create a car that sounds great but where I can listen to the radio at speed.

Side window frame

More > | Door window frames | Interior sound proofing | Radio and speaker installation |


I was strongly influenced by Rolls-Royce and Bentley while I was building this car, and the sound proofing and speaker installation meant that the standard trim would no longer fit.

A Rolls-Royce coachbuilder retrimmed the interior to my specification. The leather is Connelly hide from Scandinavia, the carpets are Wilton, and the headlining is West of England Cloth.

Leather interior

More > | Interior trim |


I have made a lot of modifications to this car so some fine tuning will be necessary to make the car as good as I want it to be. Development was held up by engine trouble - what started as a missfire progressed into a complete failure to start.

I've started developing the ride and handling. The steering was too light, the car was under damped- and the ride heights all wrong. The first job was to sort out the ride heights (below). I also have a problem with crosswind stability that will need looking at soon.

More > | V8 engine problems |- | Ride and ride heights |

Other MG Related Pages:

MGA MGA Restoration

You are here: Home > MGB V8 Conversion