The body of the MGB GT V8 sits noticeably higher off the road than the normal MGB GT although
ground clearance is reduced by 1/2" by the larger diameter exhaust system required by the V8
engine. V8 insignia are used on the radiator grille, the nearside front wing, and on the tailgate.
The only other obvious external means of identification are the Dunlop wheels.... [which have]
cast aluminium centres rivetted to chromed steel rims.
Look What's Gone Into The MGB GT V8
Superb Rover V8 in a B - at last
as published in British V8 Magazine, Volume XVI Issue 1, May 2008
Re-printed unedited by exclusive written permission of "Autocar" weekly magazine.
This article originally appeared in the issue for the week ending August 16, 1973.
by A.D. Shanks
drawing by Dick Ellis
British Leyland have now introduced the long awaited V8-engined MGB. Unfortunately,
the new car will only be available in GT form, and as such, it has stepped into a very
competitive sector of the market. The installation is well engineered, and takes account
of all immediate European emissions regulations. As the all-aluminum V8 weighes only
slightly more than the B-series four cylinder engine, the balance is not seriously affected.
Following the demise of the MGC, British Leyland have re-assessed the available power units
and decided that the timeless MGB would combine well with the aluminum Rover V8 engine from
the 3500 range. To effect this metamorphosis of the MGB, much work has been involved to
shoehorn the wide V8 engine into the narrow engine bay of the B, which up to now, has been
plenty wide enough for the in-line fours and sixes that have been used.
The cutaway diagram reveals the tight fit of the Rover V8 engine. The temperature-sensitive hot/cold air blending
valves can be seen forward of the air-cleaner cans. The external oil cooler and oil filter are shown, as are the
thermostatically controlled electric cooling fans, with their protective wire mesh cover...
Also evident is the very short propeller shaft that contributes much to the
smoothness and lack of vibration in the driveline.
To make sufficient room for the Rover engine, both the inner wheel arches and the engine
bulkhead have been changed in shape, and by setting the engine well back in the bay, it
has been possible to retain a near 50/50 weight distribution (50.7/49.3). In order to
rationalize, some of the changes that have been made to allow the V8 installation will be
introduced on all MGBs, principally because the opportunity has been taken with the MGB
V8 to change the datum points of the suspension pickups to gain a better bumper height.
It is immediatly noticeable that the V8 stands higher off the road than previous MGBs,
the height difference being 1 inch.
The variation of the Rover 3528cc V8 used has most in common with that used in the Range Rover,
sharing the same dished pistons which give a compression ratio of only 8.25 to 1. The Rover
engine is well known in its application in the Rover 3.5 litre as well as in the 3500 and
Range Rover, but its suitability in a high performance application has already been well
proven in the popular 3500S. Oversquare dimensions and a very sturdy bottom-end permit the
engine to retain its smoothness beyond its power peak at 5000 rpm up to the onset of "pumping
up" of the hydraulic tappets. In order to allow the use of the standard MGB bonnet, it has
been necessary to use different inlet manifolding to that employed on either the Rover
3500 or the Range Rover. Instead of mounting the twin carburettors on the top of a penthouse
manifold, the MGB application moves the carburttors toward the back of the engine, with
forward facing inlet tracts into a plenumb chamber approximately in the center of the vee.
In addition to meeting the requirements for bonnet height, this arrangement gives a slight
increase in low-speed torque.
The engine has been developeed to meet the ECE 15 European Emission Regulations and to enable
it to do this, neat temperature-sensitive bimetallic valves have been built into the air intakes
and are arranged to draw in warm air from sleeves on the exhaust manifolds when occasion
demands. The extremely low compression ratio enables the car to run on 97 octane (RON), 4-star
petrol. The carburettors are the SU HIF6 (horizontal integral float chamber) type as fitted to
the Rover 3500S. A change from the specification of the Rover 3500 is the use of an AC Delco
alternator as opposed to the Lucas unit.
The maximum power of the engine as installed in the MGB V8 is 137 bhp (DIN) at 5000 rpm,
while maximum torque is 193 lb./ft. at 2900 rpm, compared with 150 bhp and 204 lb.ft for
the Rover 3500S, and 130 bhp and 185 lp/ft for the Range Rover.
The gearbox is a modified version of that first seen in the MGC, and now fitted as standard
on 4 cylinder MGBs. It has synchromesh on all forward gears and internal ratios of
3.138 (1st), 1.974 (2nd), 1.259 (3rd), top gear is direct. Overdrive is fitted as standard,
working on top gear only, and has a ratio of 0.820. The gearbox casing has had to be
changed from that of the 4 cylinder car, as a larger clutch (9.5" as opposed to 8") is
required to cope with an increase in torque of 75 per cent over the 4 cylinder engine.
The clutch has a ballrace withdrawal race as opposed to the carbon ring of the MGB.
Left: The all-aluminium Rover 3528cc V8 engine is a snug fit in the engine bay, although routine service items are kept in
reach. The new inlet manifold that allows the rearward positioning of the carburettors can be seen. Right: The left-hand
fingertip stalk now controls the overdrive, as well as the windscreen wiping and washing. The necessary larger shroud
intrudes further into the base of the fascia, requiring the use of a smaller-sized speedometer and rev counter.
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The changes to the suspension are minor, and are to control the increase in torque, rather
than to have any effect on handling and ride. The spring rates are 102 lb/in at the front
and 115 lb/in at the rear as opposed to 100 and 105 lb/in respectively on the MGB 4 cylinder.
It eas not found necessary to change either the damper settings or anti-roll bar stiffness,
both being as for the MGB.
The most obvious external identification of the V8 car are the Dunlop wheels, which have
ventilated cast alloy centres rivetted to chrome steel rims. These wheels are immensely
strong, the life acceptance standards being easily exceeded on rig tests.
To cope with the increased cooling requirements of the V8 engine, the MGB V8 is fitted with
a larger radiator than the 4 cylinder car, and twin thermostatically-controlled electric
fans are used to reduce noise and power absorption. An oil cooler is fitted as standard,
as opposed to being an optional extra as on the MGB.
Inside the car, there are few changes from the normal MGB. The adoption of the American-market
column switchgear has meant that a smaller speedometer and rev counter have had to be used,
as the shroud of the steering column is larger. The fingertip stalks control the headlights
on the right hand side, and overdrive, and windscreen washing and wiping on the left hand.
The price for the MGB V8 includes most of the items that were previously available as optional
equipment on the 4 cylinder car, including overdrive, tinted window glass, heated rear window,
and a door-mounted outside mirror. The only optional extra on offer is inertia reel seat belts
which can be specified for factory fitment at £15.85, otherwise the price of £2293.96
includes all the equipment detailed in this description.
When Autocar originally published this article, they illustrated it with the cutaway drawing shown above, arranged so it spanned two pages as one large illustration. Part of the original cutaway drawing was obscured by the binding. Autocar also included four black-and-white photographs. We included two of the original photographs here, and we have substituted the magazine's cover photo for the article's two comparitively small, plain photos of the car's exterior. (We combined the original captions, above.) The car shown in the original black-and-white photos was light-colored and carried registration plate "YWL 667L".
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