A discord in C.
The MGC was born under a bad sign, or to further the musical analogy, a bum note. On paper it ought to have been a winning combination. Take a proven, popular car and improve performance and desirability with a larger, more powerful engine. Yet largely due to BMC’s parsimony, MG was saddled with a car which was met by derision. Whether the car’s short production life and paltry production numbers was a direct consequence of apathy from buyer or manufacturer remains a matter of debate, but what is evident is that the MGC was considered something of an orphan, even before going on sale.
During the pre-war era, the MG marque enjoyed something of a performance image, being offered with large-capacity six cylinder engines[1] and in certain cases, supercharging. However, post-1945, MGs had been confined to whatever small-capacity power units that could be wheedled from their Nuffield and latterly, BMC masters. Following the 1952 merger, which brought the British Motor Corporation into being, MG would end up playing second fiddle to Austin Healey, Leonard Lord’s favoured sports car marque.
By the middle of the 1960s, the Austin Healey 3000 was not only reaching the end of its commercial viability, but BMC were chomping at the bit to move on from a car which was not only costly and difficult to build[2], but shared little commonality with other BMC products. Having squandered time and resources on a number of (stillborn) alternatives, Sir George Harriman and his BMC board now sought to replace the Healey 3000 in the most expedient and cost-effective manner possible. The torsionally rigid and more space-efficient monocoque MGB body would prove an obvious jumping off point, especially given MG’s stated wish to offer a more powerful version of the strong-selling sports tourer.
Having considered a number of different powertrain options[3], it was eventually decided to equip the car with a new in-line six cylinder engine, derived from the longstanding Nuffield C-Series unit, the existing Healey engine being too bulky to be packaged within the MGB’s engine bay. By consequence, a heavily redesigned version, intended not only to be physically smaller, but lighter too was developed. According to former MG General Manager, John Thornley, MG, having been responsible for the development of the successful competition Healeys, had recommended a similar raft of improvements for this new engine.
However, this unit was also intended to find its way into a flagship Austin saloon, also in gestation at the time[4]. Hence, an element of mission creep took place at Longbridge, the resultant engine falling woefully short of expectations. “If the engine had been anywhere near right, the car would have been sensational”, Thornley ruefully told chroniclers, “but some idiot decided the engine should have seven main bearings in an already crowded crankcase.” The 2912 cc engine with pushrod operated overhead valves developed 145 bhp (net) at 5250 rpm and 170 lb ft of torque at 3400 rpm. Owing to its heavily compromised design, the revised unit suffered from greater frictional losses, and a poorly ported head, which further blunted performance. Furthermore, despite the promised weight reduction, (projected at 90 lbs), the new engine came in with a mere 20 lb weight saving and was shorter by a mere one and quarter inches.
The new powerplant was received with dismay at Abingdon, as engineers shoehorned the powertrain into the MGB hull. The most significant fallout of this related to the front suspension design. Owing to the additional length of the in-line six, Syd Enever’s team had designed a revised front end, necessitating a redesign of the front of the floorpan, the inner wings and the suspension crossmember. Instead of the MGB’s coil springs and wishbones, a redesigned layout, employing longitudinal torsion bars and telescopic dampers was schemed. John Thornley: “because of [the engine’s] weight, we had to make a botched up job of the front suspension. If we had known that the engine would be 70 lbs overweight, we would have designed different front suspension ab initio.”
Other modifications included a revised gearbox, with the option of a Borg Warner Model 35 automatic, with larger diameter front brake discs and road wheels (165 section 15″ rims). This latter change would also play havoc with the steering. Already blighted by the MGC’s front-biased weight distribution[5], the larger road wheel diameter increased unsprung weight, while reduced front castor angle necessitated lower geared steering, making for even more ponderous progress. Cosmetically, apart from badging, the C was was distinguished by the prominent bonnet bulge, with an additional nearside protuberance to clear the carburettors – both further consequences of the engine’s unplanned bulk[6].
Donald and Geoffrey Healey had been involved with the programme early on, with BMC’s initial intention being to offer the C in both MG and Austin Healey form[7]. However, by the time development was complete, Healey had washed his hands of it, nor for that matter was there much by way of compensatory enthusiasm at Abingdon. This was reflected in the C’s introduction and subsequent production life; the suspicion being that the car had progressed too far to cancel, there being little real impetus to market it once MGC became available in the marketplace[8].
Adding insult to injury was the fact that in addition to its more obvious failings, the car simply didn’t offer a sufficient advance (cosmetically or dynamically) over the MGB, to say nothing of the Healey 3000, certainly not by 1967 standards. Buyers expected more, but BMC attempted to do the whole thing on the cheap. The C therefore just further emphasised the dysfunction within BMC senior management, as the car giant lurched towards its 1968 date with destiny.
The critical tongue-lashing the car received must have made for sombre reading at Abingdon; the press vocalising the hitherto unthinkable, a dynamically suspect MG. The car’s ponderous nature extended beyond dynamic failings[9] to its power unit, the new six proving stubbornly resistant to respond as a performance car ought, although once finally up to speed, the C did prove quick.
Not that it couldn’t have been developed into a far for capable machine. MG’s own works developed cars sported alloy heads, triple choke weber carburettors, all-round disc brakes and a rear anti-roll bar, amongst other modifications and with these changes gained something approaching a competition pedigree. Back on planet earth, Downton Engineering worked their own form of alchemy upon the C’s engine, modifying both cylinder head and manifolding in addition to fitting a lighter flywheel – the Downton MGC gaining 10 mph in top speed and shaving almost 2 seconds off the 0-60 time. Even fuel economy was improved over the standard car.
The C was withdrawn from the market in September 1969, with only 4542 roadsters and 4457 GTs made. However, around 170-200 unsold MGC GTs were obtained and modified by London MG dealer, University Motors[10]. Further underlining the car’s unrealised potential, they sold strongly are are highly sought after by aficionados today[11].
Penny-pinched to death, the MGC gave a poor account of itself, and its production life was, to paraphrase Thomas Hobbes, nasty, brutish and short. Described by Car magazine as “a desperate attempt by cost-conscious engineers”, the MGC spelled expedience in neon. The irony however was that buried within the C was the bones of a half decent car. As to the other half? File under yet another of Harriman’s follies.
[1] The MG six-cylinder engine was derived from a Wolseley unit.
[2] Jensen Motors built the Big Healey’s body and chassis and it’s been suggested that the relationship between West Bromwich and Longbridge was a rancorous one.
[3] The following is quoted directly from the MG Owners Club. “The existing 3 litre unit used in the Healey 3000 was deemed unsuitable as it stood and a refined version of the four cylinder 2.6 litre Austin Healey engine was suggested but promptly rejected. There was also an idea to use an Australian version of BMC’s 2,433 cc six cylinder unit, which utilised triple SU carburettors and was basically a development from the four cylinder B series engine. This was not taken up because of too many political, spares/service and economic problems”.
[4] The saloon in question was the unloved ADO 61 Austin Three-Litre.
[5] 55% of the MGC’s weight sat over the front wheels.
[6] One positive by product of this was that the bonnet hump provided an immediate visual differentiation from the lowly MGB.
[7] Given development codes of ADO 51 (Healey) and ADO 52 (MG), the cars were to be differentiated purely by grille treatment and badging, à la Spridget. BMC made a concerted effort to get Healey to change his mind, but he was immovable. The Healey 3000 MK IV remained stillborn.
[8] One notable MGC owner was the current Prince of Wales, the royal household taking delivery of a C GT in 1969. His impressions are undocumented.
[9] One area of the MGC’s dynamic envelope that was praised by Car Magazine was the C’s ride quality and refinement. However, of sporting prowess, they could discern none, outlining understeer of “monumental proportions” and noting the “superhuman effort to deflect the car from its chosen path”. Hardly ringing endorsements.
[10] A select number of these were also modified by Downton and all came with additional distinguishing features; special paintwork, road wheels, dampers, badging etc.
[11] Ironically, all MGCs are highly collectable now.
Sources: Classic and Sportscar – April 1985/ Car Magazine – October 1968/ MG Owners Club
Driven To Write 
Good morning Eóin, and thanks a lot for well-considerd portrait of how MGC came to be. Still, with all its flaws, clearly the result of penny-pinching and murky internal politics, this is an interesting one: small, stylish and highly capable roadster (or GT) with a big 6-in-line that can have an almost-musical exhaust note: what’s not to like? With the politics that damned it, it seems the decision to have suffered most from the engine being shoe-horned into a body full of its own character, while the changed weight distribution and suspension set-up called for a totally different take on the resulting car, which would be more GT-like (albeit in a tiny package). Still, i want one, in red please, if the trusty ID21 were ever to give up and the children have left the nest…
Good morning Eóin. The MGC really was a perfect example of the half-arsed “it’ll do” attitude of BMC management towards product development, which continued well into the 1970s. It must have been so frustrating for the engineers, knowing full well that the car was a dud, yet having to watch it go into production in the expectation that it (and their reputations) would be trashed as a consequence.
Even the modified bonnet could have been done so much better. What was that chrome strip across the front of the hump all about? It just drew attention to how awkward looking the hump was:
Why didn’t they instead have an open air intake at the front of the hump (even a dummy one) to give the car a bit of visual muscle?
Under the chrome strip is – a welding seam, what else. It would have been difficult to stretch the metal of the bonnet into a bump like this with the cheap equipment available.
Which would leave you with something like this (only better executed, hopefully):
That’s exactly what I had in mind, Tom. Nice work! 👍
🙂 Thanks!
With the exception of the Rolls-Royce powered Austin-Healey 4000 prototype (as in ADO24 rather than ADO30), which should have appeared much earlier in the 1960s and helped push the Big Healey further upmarket. It seems that the Austin-Healey marque was nearing the end of the road, especially in light of the Healeys growing frustration at BMC particularly with ADO51 or the Mark IV Big Healey version of the MGC that properly should have been better differentiated in terms of styling (if not carried over much of the ADO30’s exterior).
There also seemed little serious interest on the part of the Healeys in properly replacing the Sprite besides the Healey version ADO34 and Healey WAEC. It is difficult to see what else could have been done with the Austin-Healey marque beyond being tarted up slightly upmarket MGs or basically being the sportscar equivalent of Riley.
Should the Healeys and Jensen Motors for that matter have seen what lay head and sought to strike it out on their own earlier, with the possibility of still utilising BMC (or BL if it still happens) mechanicals at a distance?
Had BMC acquired Rover instead of Jaguar, there would have been an opportunity for the Healeys version of the MGC to have instead utilized the Rover V8 in place of the existing options considered during the MGC’s development (did wonder if the P6 OHC or even the P10 DOHC engines would have been suitable for an upmarket Healey-ized MGB or alternate Jensen Healey).
Have read in both David Knowles books on MGB/etc and Jon Pressnell’s book on Austin-Healey that the refined version of the 2.6 Austin D-Series 4-cylinder engine used in the Big Healey was to use the same displacement as the 2.5 diesel introduced in 1971 in the Austin FX4D (and remaining in production until 1982 before being temporarily revived in the FX4Q till 1984), yet to feature a Twin-Cam head with outputs of around 142-180 hp
The story of the refined Austin D-Series 4-cylinder engine would help explain BMC’s apparent interest in the 151 hp 2.5-litre Aston-Martin DP208 4-cylinder engine used in the Volvo P1800, which at the time was also assembled at Jensen. Where the absurd rumour of the Aston-Martin engine being tried in a Frogeye Sprite, was actually instead more plausibly referring to the Big Healey likely (given the time period) as a possible benchmark for the projected Twin-Cam Austin D-Series engine to be used in the Healey version of the MGC.
https://www.bosmobil.com/aston-martin-3/us.html
The mention of Jensen and the Healey 3000 made me think of another West Bromwich assembled product – the Sunbeam Tiger.
MGC comparisons are telling. Both had production runs of three years, around 10,000 MGCs were made, compared with 7083 Sunbeams, which I’d say was still a win for Rootes and Shelby as the Tiger was try-it-and-see side project with a tiny development budget. The MGC, on the other hand, was to be MG’s flagship, and of course a challenge to Triumph’s fuel-injected* TR5 and TR6. That didn’t go entirely well…
*Except for viewers in the USA.
Given the attractiveness of a straight-six MGB/MGB GT derivative, it’s such a pity that it was executed in his manner.
Agreed, Konstantinos. The idea is sound, the engineering less so. The bulge on the bonnet and the added bump for the carbs have always bothered me. Still overall I think it’s rather nice.
The bulge on the bonnet and the bump for the carburettors are things I can take or leave; I’m not too fussed by them – perhaps I’d do away with the chrome strip on the hood. As for the car having an inferior front system set-up, that is a disadvantage.
Afternoon Eóin, thanks again for another great article. Every time I read about the sheer incompetence of the BMC management it makes me shudder. It’s like everything they could do wrong, they did so, from sheer bloody mindedness. Almost as if it was done deliberately; “I’ll do the opposite of what is obviously correct because nobody tells me my business, not even reality itself”.
I mean, not to put it down, but what was the point of the whole Austin Healey venture anyway? They’d have to consult with Healey, pay him money, MG was already there and was seen as highly desirable (including in America)…Austin-Healey just made no business sense to me. Yet again it just reads like spiteful bloody minded stubbornness. MG was ‘not mine’ ergo I’m going to ruin the whole business trying to undo it. So stupid.
The MGC could have been a world beater with some proper forward planning. By the late 60s you had the likes of the Fairlady and the Capri (and the Sunbeam Rapier) showing the way in affordable sports cars. But nope, they decided to just awkwardly cram an inadequate engine into the old car and call it a day. “That’ll do”. Such a shame.
The point of the Austin-Healey was that Donald Healey made the entire car on spec, and when it was presented as a “Healey” at the 1952 London Motor Show Austin chairman Leonard Lord was so impressed they came to an agreement of a joint venture then and there and Austin hastily presented it as an “Austin-Healey”.
They were essentially handed to them an entirely production ready sports car project based off their own in-house mechanicals, and it only cost them a percentage of future profits, so it really was a no-brainer accepting the offer.
Here’s Prince Charles’s MGC. He liked it very much, apparently and has given it to his son, William.
I’ve always liked the MGC – it’s okay if set-up correctly, which some of the press cars weren’t (as was traditional with BMC / BL).
If someone had to ask me to outline the steriotypical MBC / Leyland car development it would look like this.
And what did they learn from it? That they should repeat the whole process of making a brand new engine that was worse than an already existing option with the Stag.
Here are two pictures for comparison:
The MGC engine installation:
And the August 1973 MGB GT V8:
The shape of the C’s bonnet bulge is mainly dictated by the height of the radiator. Was it not possible to find one more compact and suitably shaped? Note that owing to the location of the alternator, the V8’s radiator is similarly far forward, but low enough to avoid the conspicuous bulge. Capacity is 16 pints, against the four cylinder’s 9.5. The C’s capacity is quoted as 18 pints. The V8 has twin electric cooling fans, rather than the the C’s engine driven single one.
I read somewhere that the tooling for the MGC bonnet was adapted and re-used for the V8, which has a higher and more rounded profile than the B-series cars, although hardly noticeable without an example of both for comparison.
In an interview, Don Hayter, MG’s Chief Engineer, said that the engine was about one and three quarters of an inch too tall and Syd Enever made some suggestions to Issigonis about making it more compact and improving the breathing, but he wasn’t interested. Much as I greatly admire Issigonis, someone really ought to have had a quiet word. When this series has finished I’ll post the interview.
For another comparison, here is the six cylinder version of the ‘B’ series, the ‘Bluestreak Six’ developed in Australia. Based on the 1600cc version of the ‘B’ series, but capable of taking the bigger bore /stroke of the 1800. So starting out as 2.4 litres, going to 2.7 litres later.
But since this came from the Morris side of BMC, not the Austin side, and worse, from the colonial outpost of Australia, (and even more worse, block casting by Ford Australia.), and despite doing well in testing, the decision was made to go with the ‘C’ series and all the packaging compromises imposed by it’s bulk and weight.
The ‘Bluestreak’ of which 27,000 were made for Austin Freeways and Wolseley 24/80s which would have used all the ‘B’ series tuning expertise, and weighed only 40 lbs/18 kg more than the four cylinder, making it a straight-forward bolt in proposition wasn’t used, and the no more powerful 350 lb/130 kg (!!!) heavier ‘C’ series was shoehorned in.
A few MGBs have had the ‘Bluestreak Six’ installed in Australia and NZ and they drive very well.
And here’s an illustration showing that torsion bar suspension, at least partially:
Without more detail of the upper wishbones it’s hard to judge whether the change to torsion bars was REALLY necessary. The quoted track width for the MGC is just one inch wider than the MGB, and may just be down to wider tyres and a different wheel offset.
There seems to have been an opportunity missed in not devising an improved front suspension shared by the four and six cylinder cars. The MGB, including the 1973 V8, continued with lever arm dampers front and rear until the bitter end.
As far as improved front suspension goes, what arrangement was within BMC’s ability to develop at that point?
I’m trying to work out if the MGC’s torsion bar / telescopic shock absorber set up had its origins in competition MGBs, particularly the ‘Sebring’ cars. It’s got to be better than something lightly adapted from a mid-’50s Austin Cambridge, and there’s no reason why it shouldn’t work well on a road car. As always, it’s not the principle, but how it is applied. It had the potential to be the MGC’s technical bright spot, rather than part of the roster of failure.
Likewise I’m surprised at the opprobrium directed at the decision to re-work the C-series engine to seven main bearings. If it was a tight little ultra-long stroke engine with siamesed bores* I could accept the argument, but the 2912cc C series is moderately undersquare and has water passages between each bore, which says to me there’s plenty room to fit in these three extra bearings. The Jaguar XK has seven main bearings, likewise Chris Kingham’s well-regarded Alvis 3 litre engine. By the mid-late ’70s Rover (actually the remnant of Triumph), and Mercedes Benz were being denounced as miserable bums for making the PE146/166 and M123 sixes with only four main bearings. Theoretically there are friction and weight disadvantages in providing extra bearings, but they are outweighed by the additional integrity they provide.
*E6, Im looking at you. And you have seven bearings. And worked rather well, particularly in RWD-only 2.6 litre form.
Fwiw the following article below states the standard C-Series was actually producing as much as 124 hp at the flywheel as opposed to 145 hp. – https://holmesracing.co/how-to-improve-a-mgc-by-vic
While the Downton stage 3 conversion for the MGC managed to increase output to 174.6 hp, with later tuning increasing the output to 190-200+ hp.
Still one can only imagine how a properly run BMC (plus Rover) could have completed the MGB, MGC and Big Healey range with just the B-Series 4/6-cylinder and Rover V8 engines.
– MGB 1.8-2.0 with 94-106 hp – with potential for 130+ hp
– MGC 2.4-3.0 (Blue Streak) with 115-160 hp – with similar potential for 200+ hp as revised Downton spec C-Series
– Austin-Healey 3500/4000 V8 with 155-190+ hp – essentially an earlier Healey bodied non detuned MGB GT V8 meets MG RV8, read the 4-litre V8 could have appeared about 2 decades earlier had P8 reached production.
Good Afternoon Robertas
Yes, it isn’t necessarily the case that seven mains are always necessary for an in-line six. Even a V-12 doesn’t necessarily need a seven main bearing design. Nor does a flat-12. Take as examples these engines.
– Lagonda V-12 (Stewart Stewart Tresilian)
– Ferrari 312 Boxer (Mauro Forghieri)
They featured four main bearings in the crankcase. In both cases the designers sought to reduce friction, especially as rpm increased.
Tresilian is recalled to have stated that where the crankshaft deflected he counterbalanced it (added balance weights) and where it didn’t he supported it (provided mains). He also observed where there were no bearings there was no friction. His designs certainly did possess mechanical integrity.
Tresilian was highly regarded in engineering circles, as it was he who solved the Rolls Royce Merlin V-12 crankshaft torsional problems. Tresilian’s reputation was, according to Walter Hassan, legendary across the industry. He certainly knew a thing or two about crankshafts. Tresilian did not consider that it was always necessary to provide seven mains for a V-12, or five mains for an in-line four. So, if less than seven mains could be sufficient for a V-12, so too for an in-line six.
As always in engine design, it all depends…..
I suppose that in the case of the BMC C series the strongest criticism of the late-life conversion to seven main bearings is that it was a lot of effort for little or no discernible benefit. The money could have been better spent on a better ported alloy cylinder head, for example. Once again, third party specialists stepped in where BMC/BLMC feared to tread. There was also talk of reworking the engine’s proportions to make it oversquare, possibly with a reduced deck height, for the MG application. That would probably have meant siamesing some or all of the bores. It didn’t happen, so hardly worth mentioning.
I am however put in mind of the Rover OISE engine, which also gained another three main bearings for the 1958 P5. The reworking of the engine from its P4 origins was so extensive that that they could have covered the cost of designing and tooling an all-new unit. What’s worse, the four main bearing P4 engine could be stretched to three litres (2995cc, 78.8mm x 102.4mm) with relative ease and good results. There are, no doubt, traditional Roverists who will claim that the P5’s straight six was the finest engine ever to power a Rover, but I’m pragmatic enough to point out that a GM cast-off wiped the floor with it, and transformed the Rover 3 Litre from an underpowered also-ran to a national treasure.
The James Taylor book on the Rover P5 claims the rationale behind the redesigned P5 3-litre Six was because the 1953 2.6-litre’s block did not allow room for the even larger bores which Norman Bryden needed for the 3-litre engine, with the bores spaced even further apart.
One alternative was a 3-litre V6, however the oversquare short-stroke architecture of the 2950cc V6 did not marry well with the IOE configuration that had been designed in the thirties for a long-stroke engine. Resulting in an engine that simply could not be persuaded to rev high enough, the best figures achieved being 100 hp at a low 4000 rpm before it was abandoned.
Would have thought by that point Rover would have switched away from IOE much sooner than it did with the P6 had they opted for an all-new unit.
According to the Eric Dymock Rover history -mine’s a 1993 edition – the enlargement of the 2.6 OISE straight six was a bit of desperation after Jack Swaine’s V6 was finally abandoned. Work had started on that one in the 1930s, and Swaine had been working on the post-WW2 iteration since 1950. The V6 engine was highly unconventional, with an OISE valve arrangement, carburettors outside the vee, and the exhaust manifold in its centre. It also had a 90 degree vee angle, and a V8 developed in parallel had a 60 degree vee angle.
Another option that was considered was using the same 77.8mm bore size as the four cylinder OISE engine from the P4 60. The widening of the bore centres and extra main bearings came by the edict of Maurice Wilks, who insisted on having water passages between each bore and as strong a bottom end as possible, in the interests of engine durability and refinement.
Was not aware of a V8 prior to the all-alloy Buick engine, the James Taylor book also seems to pin the V6 down as a 60-degree design.
Thinking about it further, the cost savings a cheaper less extensive redesign of the 3-litre Six would have allowed Rover to introduce some form of a P7 Six in the 1962 mk2 P5 to replace the IOE Six (if not also other spinoffs). A scenario with the potential to negate Rover’s interest in the 215 Buick V8, short of the latter receiving a mild stretch beforehand.
“BMC were chomping at the bit to Continue reading” – ha ha! 🙂