At last - V8 power for the MGB
THE idea of dropping a V8 engine into the MGB has been under active consideration ever since the Rover 3500 was introduced in 1968, and the project was given the go-ahead two years ago spurred on, perhaps by the praise bestowed on Ken Costello's limited production version. This week on the 50th anniversary of original MG produced by Cecil Kimber, British Leyland announces the MGB powered by their 3.5-litre alloy block V8.
as published in British V8 Magazine, Volume XVI Issue 1, May 2008
Re-printed unedited by exclusive written permission of "Motoring News".
This article originally appeared in their issue for the week ending August 16, 1973.
Externally the new model is almost identical to any other Grand Touring version of the
"B", distinguished only by the special Dunlop alloy/steel wheels and the V8 badges around
the bodywork. There is still only one exhaust tailpipe, so from the front and rear views
there is nothing but a tiny chrome badge to give the game away. Perhaps a lot of people
will be disappointed that the eight-year-old GT design couldn't have been given a facelift,
but it remains one of the most attractive compact sports cars on the market and the V8
version sells for the not unreasonable price of $2293.96 plus Kangol automatic front
seat belts ($15.85), delivery, number plates, etc.
Even ten years ago the MGB (with the 1.8-litre engine which continues in production) did
not have enough power for everyone's needs, so we can say that better late than never
the B-V8 has been given a tremendous power boost which should suit most customers, and
becomes an extremely practical and desirable road car. Mechanical changes include heavier
road springs at the back, thicker brake discs, and a repositioned steering rack. The end
product is a model which will accelerate from rest to 70 mph in 12 seconds, cruise at 110
mph all day in overdrive with 4000 rpm showing on the rev-counter, and still return better
than 20 mpg (on 3-star petrol) in normal conditions.
Vee-eight powered sports cars have always had special appeal for enthusiasts, and models
like the Daimler SP250 and the AC Cobra are still fondly remembered... even the Sunbeam
Tiger raises some good memories, through chassis development was rather lacking. The MGB GT
(fixed-head) has none of the torsional stiffness problems that other British V8 powered
sports cars have suffered from, and the marriage of this chassis and the Rover engine seems
so natural that it's hard to understand why it wasn't done before. The all-alloy V8, nee
Buick, is in fact 40 pounds lighter than the B-Series 1.8 litre four-cylinder, and produces
137 bhp DIN with the compression ratio lowered to 8.25:1. By the time the engine is installed
it weighs a few pounds more than the B-Series due to the fitting of an alternator and all
the exhaust emission equipment needed to suit the American market. The front/rear weight
ratio is 49.4/50.6% compared with 47.8/52.2% for the four-cylinder.
The extra weight at the front however is compensated for by moving the steering rack forward
one inch, reducing the Ackerman angle and making the steering more direct. It certainly doesn't
feel heavy, and the V8 model has no drastic understeer tendencies - it is, in fact, everything
that the ill begotten MGC was not!
Contributing to the extra weight at the front are thicker 10.7in. diameter disc brakes,
half an inch in width, also having new Lockheed calipers and larger pads to increase the
swept area: a servo is installed as standard equipment.
The V8 engine slipped into the available space without too much shoe-horning, and
accessibility is very good all around. Helping here is a pair of electric cooling fans in
front of the larger radiator, reducing the overall length of the engine. The principle
modification in the engine bay was to the front cross-member, but what immediately strikes
the eye is the clever induction manifolding system. So as to avoid having a big power bulge
in the bonnet to cater for the twin SU HIF6 carburetters, the Abingdon engineers devised a
new dual manifold which allows the carbs to sit at the back of the engine, close to the
bulkhead. It is said that the new manifold reduces temperature scatter from one cylinder
to another compared with the penthouse manifold, which should make the engine smoother
running. Hydraulic valve lifters feature on this V8, which limits engine speed to 5200
rpm and inhibits all but the most persistent engine tuners, although the emission equipment
on the engine and low compression ratio account for something like 25 horsepower.
Detail modifications have been carried out to the all-synchromesh C-type gearbox and rear
axle. The gearbox casing has been redesigned to accept the larger Borg-and-Beck diaphragm
spring 9.5 inch clutch, which has a ballrace withdrawal instead of the more usual carbon
thrust bush. The DIN power figure is increased by almost 50% compared with the MGB and the
torque is practically doubled at 193lb.ft., so the intermediate gear ratios have been raised
to match the power and to reduce the torque load into the box. The final drive ratio is
3.07:1, compared with 3.91:1 for the 1.8-litre version, giving very long-legged cruising
capability indeed.
Suspension changes are fairly mild, entailing the usual upper and lower wishbones with
heavier coil springs, though with the same lever-type dampers and an anti-roll bar. At
the rear, heavier semi-elliptic springs are fitted, again with unchanged lever-type dampers,
to cope with all the extra torque, and it must he said that this has a significantly
detrimental effect on the low-speed ride. Also interesting are the Dunlop 5J x 14 wheels,
which have alloy centres rivetted to chromed steel rims. These are very handsome, having
the MG octagon motif on the hubs, and are said to be the strongest wheels ever fitted on
an Abingdon product. The test batch withstood three million reversals, and one wheel was
still intact after six million reversals on a test rig.
Apart from the AC Delco alternator, other equipment included in the MG's standard,
basic equipment includes Laycock LH overdrive on top gear only, the Dunlop wheels,
a brake servo, a door mirror, and tinted glass all round; the windscreen is laminated,
and the rear window electrically heated. An oil cooler is another item of standard
equipment.
ON THE ROAD
The MGB GT concept does not need much introduction, but it is some time since the
writer has driven one and time has done much for the car. The cloth trimmed seats
are infinitely more comfortable and offer much better location than the skimpy
leather seats did, and the backrests are fully adjustable. The steering wheel is
still rather large, but the 15.5 inch diameter wheel is now vinyl bound and pleasant
to handle. The Smiths instruments are slightly smaller than before (3.13 in. diameter
instead of 4 in. diameter) to make space for the collapsible steering column, which
is now mandatory for cars sold in America.
There is ample headroom and legroom is more than adequate for the driver and passenger
although, with the seats well back (as the driver's needs to be, to get a decent arm's
length approach to the steering wheel), there is no space whatsoever for legs dangling
from the vestigial back seat. A small child could sit or lie across the back seat, but
that's all. On the other hand with the back seat folded flat, there is a generous area
for luggage and the tailgate door makes access very easy.
Primarily this is a car for one or two people, who can make themselves comfortable and
settle down to enjoy long distance motoring. The bulkhead mounted pedals are in line
with the drivers lap, which gives a direct line of attack, and are well laid out for
heel-and-toe downward gearchanging. There is also plenty of foot-room not always found
in sports cars.
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Full choke is needed to make the engine start readily, even in summertime, and the
engine maintains the infuriating BMC trait of needing plenty of choke to keep going
while it is warming up; that means that the engine is kept revving artificially at
the lights. That's about our only criticism, for the smooth, quiet V8 (it has a well
baffled two-into-one exhaust system) relies on its tremendous torque to send the car
surging forward in response to the throttle. Give or take a mile or two per hour, the
maxima in the gears are 40, 60 and 100 mph, with 122 mph available in fourth and
approximately 126 mph in overdrive. These speeds are achieved with the minimum of
fuss and effort, yet with the appropriate amount of satisfaction.
Naturally the car is extremely tractable and it will pull from below 20 mph in fourth
gear without snatching. The clutch is not particularly heavy, so the 'B' is ideal as
ever in traffic (perhaps better, with the high first gear which reduces gear-changing
in rush hour conditions), and a real goer on the open road,
As we mentioned, the ride on poor surfaces is distinctively hard at low speed, and
potholes can really jar one's teeth. This isn't so noticeable at higher speeds, though
a big bump can put the car slightly off line, and on the credit side there is hardly
any body roll to make life more difficult.
Steering is taut, with plenty of feel, at low speed and this no doubt is why the MG
development engineers keep going with the now unfashionably large steering wheel. At
higher speeds, and particularly when the car is being driven hard, a driver might wish
for a smaller diameter rim.
On the road, understeer is the predominant steering characteristic though it's not
pronounced, and can be neutralized by lifting the throttle. Generally it feels a nicely
mannered, well balanced car. Opinions among our staff divided sharply when we pushed the
car harder at our Chobham test track, for the understeer/oversteer characteristics became
very marked on the handling course and it would take a fairly experienced driver with his
wits about him not to get into trouble.
The understeer is very pronounced with power on, but releasing the throttle (perhaps to
get round the corner at all) sends the tail out with a lurch and the inside front wheel
paws the air several inches off the surface. An experienced driver will use this
characteristic to advantage, but we thought that an 18-year-old millionaire pop idol
could easily make headlines if he got caught out on a slippery road.
The B-V8 made an interesting comparison with the Dolomite Sprint and the Ford Escort
RS2000, which we were enjoying on the same occasion. The Dolomite understeered
dramatically and couldn't touch the B-V8 on our favourite snake course, while the Escort
had handling clearly superior to either of them but lacked the power of the MG. By the
time we had finished, though, we thought that the British motor industry has plenty to
offer keen drivers these days, so why devalue the pound any more by buying foreign?
Straight line acceleration is clearly impressive. Such is the traction provided by the
Goodyear 175HR14 tyres that our first start with the fifth wheel attached merely slipped
the clutch and a slow time was recorded, but using 4000 rpm the rear wheels break away
cleanly and the tail end of the car snakes strongly on dry tarmac. The gearchange is
rather chunky and notchy, though the movements are swift and short, and the small gap
between first and second ratios is rather noticeable. Third is a long, strong gear
though, taking the car up to 98 mph. and we just managed to record a zero to 100 mph
time, 26.9 seconds. More impressive is the 19.8s time to 90 mph, performance clearly
dropping away when fourth is selected.
The engine is very lightly stressed and is smooth right through its range. At 100 mph
the wind noise begins to build up, but the mechanical noise is unobtrusive and 110 mph
is an honest, untiring cruising speed. Figures released by BL show that it averages 20
mpg at a steady 100 mph in overdrive, and our creditable overall fuel consumption of
22.8 mpg means that the 12-gallon petrol tank will allow a cruising range of at least
250 miles.
The brakes felt rather heavy, but progressive, and the pedal still felt firm after
several rapid laps of the handling course. Lucas sealed beam headlamps are specified,
with a 75 watt main beam and 50 watt dipped beam, and with these we were quite happy
to cruise at 100 mph at night.
Controls are quite a lot better than they used to be, the main functions performed by
two stalks from the steering column: the right-hand lever works the indicators and
dips and flashes the lights, the left-hand lever controlling the wipers, washers,
and although obscurely marked, also controls the overdrive which needs just a little
practice to disengage without a transmission bump. The ignition key has one of these
new-fangled button overrides, which means that you can't get the key out without
pressing the adjacent pimple. We expect there's a good reason for it, but it escapes us.
Heating and ventilation is much better than it used to be, though not so efficient
or controllable as Ford's, and the comprehensive equipment sheet includes things like
a dipping mirror, a centre armrest with a tiny cubbyhole underneath, a maps pocket by
the passenger's legs, twin reversing lights, and rubber capped overriders.
The underside of the bonnet is felt soundproofed, and the engine is very neatly
installed with excellent accessibility to the coil, distributor, alternator, carburetters,
and dipstick. A couple of the plugs would be awkward to reach without a universally
jointed socket spanner. To finish the job off, the rocker covers are nicely made in
ribbed alloy with the MG octagon displayed prominently; the ancestry of the engine may
be far removed from Abingdon, but there's no need to remind everyone on MG's 50th birthday!
We were impressed with this MG, no doubt about it. There are cars, even saloons with
3-litre engines, which accelerate faster and ride better, but they're not sports cars
with those indefinable "fun" characteristics, and apart form the excellent Ford Capri
3000 they cost two or three times the price. Despite a hard ride, despite the fixed roof,
despite its two seat only capabilities, despite its clumsy and tongue-twisting name
(why not the Magna?), the MGB GT V8 is going to make a lot of friends. To finish with
the good news, production was built up to 50 cars a week a couple of months ago, and
the initial run is reserved for the home market. Please form an orderly queue.
-M.L.C.
SPECIFICATION
Engine: All alloy 90-deg V8, front mounted, driving the rear wheels. Water cooled,
with twin thermo fans. Central camshaft, pushrods and rockers. Bore and stroke.
88.9 x 72.1 mm. Capacity 3528 cc. Maximum power 137 bhp DIN at 5000 rpm, maximum
torque 193 lb/ft DIN at 2900 rpm. Compression ratio 8.25:1 (3-star fuel). Carburation
by twin SU HIF6 sidedraught carburetters.
Transmission: BL C-type 4-speed all-synchromesh gearbox, Borg and Beck 9.5in dia
diaphragm spring clutch, hypoid bevel differential with 3.07:1 ratio. Laycock LH
overdrive on top gear only. Gearbox ratios: 1st. 3.138; 2nd, 1.974; 3rd, 1.259;
4th. 1.0; overdrive 0.82: Reverse, 2.819:1.
Mechanical: Suspension front, independent with upper and lower wishbones, coil
springs, lever dampers and anti-roll bar; rear, live axle with semi -elliptic leaf
springs, lever dampers. Brakes, Lockheed hydraulic with l0.7in dia discs front, lOin
drums rear, with servo. Steering, rack and pinion 16.417 ratio, 2.93 turns on 15.5 in
dia steering wheel lock to lock.
Dimensions: Overall length 12 ft 10.75 in; width 4ft 11.9 in; height 4 ft 1.9 in; front
track 4 ft 1in; rear track 4ft 1.25 in; turning circle 33 ft 7in (avg); fuel capacity
12 gallons; kerb weight 21.6 cwt.
PERFORMANCE
|
Acceleration: mph --- secs 0-30 --- 2.8 0-40 --- 4.0 0-50 --- 6.5 0-60 --- 8.6 0-70 --- 12.1 0-80 --- 15.9 0-90 --- 19.8 0-100 --- 26.9 |
Speeds in gears: 1st --- 39 mph at 5200 rpm 2nd --- 60 mph 3rd --- 98 mph 4th --- 122 mph o/d --- 126 mph |
|
Standing start 1/4-mile: 16.4s.
Speedometer accurate at 70 mph. |
Fuel consumption: 22.8 mpg.
Price: £2293.96 plus seatbelts, etc. |
When Motoring News originally published this article, they illustrated it with
three black-and-white photos. Our copies weren't suitable for reproduction, so
we've substituted a photo from Ken Smith's personal collection. Here, for the
sake of completeness, are the original captions:
Photo 1: "The MGB V8 goes through its paces at Chobham, pursued by the Dolomite Sprint
which we report on next week. These two fine British Leyland cars display
opposite extremes in handling. The Dolomite understeering strongly and the
MGB lifting a wheel on trailing throttle."
Photo 2: "The V8 engine goes neatly into the MGB's bay with small alteration
to the front cross-member and the wheel arches. The carburetters are located
well back, on a new induction manifold. An oil cooler is located in front of
the two "pusher" electric fans."
Photo 3: "NEW-LOOK interior for the 'B' includes a revised fascia with a centre
console, a gaitered gear lever and cloth seat upholstery."
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