Conversion of the Chrome Bumper MGB 1800 Engine Bay to suit Rover V8 Engine

Unlike the black bumper MGB, the chrome bumper model requires a number of modifications to the engine bay. Once these have been completed, the conversion is continued as for a black bumper model.


If you are using a pre SD1 Rover V8 engine i.e. P6 or P5 the front of the sump pan will have to be modified to clear the front suspension cross member.

The following modifications have to be made to the engine bay:

1.    Fit new chassis rail engine mounts

2.    Modify steering shaft

3.    Remove radiator mounts and fit later type

4.    Cut away front pan and strengthen

5.    Cut away bulkhead

6.    Resite brake light switch

7.    A dish is required in the inner wing to clear the exhaust manifolds

Details of these modifications are given below.

Detailed Explanation of Modifications to Chrome Bumper MGB Engine Bay

After removing both front cross-member fixing bolts, the original 1800 chassis rail engine mountings should be cut away completely and the surface cleaned up. The new chassis rail engine mounting for the steering side is relieved to give clearance around the steering shaft. Both engine mount front supports have to be formed around the front cross-member bosses. When the new mountings are in place, access to the studs of the engine mounting rubbers is very limited, so before the mounts are welded to the chassis rail a depression should be made in the side of the chassis rail adjacent to the slot in the mounting.

It is advisable to tack the mounts and check the installation before finalising the welding.

The original steering shaft is fitted with a large universal joint at the bulkhead. This obstructs the V8 exhaust manifold, so a special shaft and pinion have to be fitted, with 2 smaller joints, one at the bulkhead and one at the rack. The lower end of the column should be dropped in its brackets as far as possible.

Because of the extra length of the V8 engine, the original radiator mountings have to be removed and the later radiator mounting plates welded in place.

The front pan has to be cut back to allow the V8 radiator to be fitted. A section of steel U-channel is fitted into the front to strengthen the structure. If the oil cooler is to be retained, it can be mounted in front. This is best done when the cooling fans are fixed, as space is rather limited.

The bulkhead has to be cut back to give adequate clearance for the Rover heads and also to assist in engine/gearbox fitting and removal.

The brake light switch mounted on the off-side inner wing is extremely close to the V8 exhaust manifold, and should be resited.

A dish will have to be fabricated in the inner wings to clear the front of the exhaust manifolds. This can be dressed back or a section could be cut out and a flat or concave panel welded in place. On later chrome bumper and rubber bumper vehicles a dish already exists however this will still need increasing at lower edge.

Tel: 01689 858716           eMail: V8Conversions@mgbv8.co.uk