With almost 50 per cent more power (six pots of it, too!) the MGC looked like the perfect MGB, but with more sting. However, it didn’t turn out that way and, after just two years and less than 9000 sales, MG’s answer to the Big Healey was dropped.

Most critics blamed the sleepy 145 horses (which was an optimistic claim, to say the least) and the severe understeer caused by that heavy truck-derived engine, but today the MGC is looked upon far more favourably as a relaxing MGB, tailored for touring. Perhaps this facet, and the car’s rarity, is why many owners prefer to keep theirs as standard, but there’s a fair old bit you can do to make an MGC better for today’s roads, as well as making it more than up for some mild classic motorsport.

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Long before the MGB was launched, MG had thoughts about making a six-pot sports car along the lines of the Big Healey and, while the engine was actually the same in cubic capacity as the Healey unit, it wasn’t the same one. Instead, this was a newly designed unit that was also fitted to the new Austin 3-litre saloon, albeit in a softer tune. Though two inches shorter than the old Austin ‘six’ it still weighed in a whopping 210lb more than the old B-Series.

The best thing about the MGC is that prices fall very much in line with its later V8 replacement – and this means strong value for money. Predictably, roadsters are worth significantly more than GTs, and carry hefty premiums. While a project GT that’s complete can be bought for £2500 or so, an equivalent roadster is more like £4000. Similarly, a decent GT makes a worthy £6000 while a roadster is closer to £8000. The best open-topped Cs have been known to sell for the thick end of £20,000.

Like the MGB, rust is the chief concern on the floor, outriggers, sill assemblies, inner wings, rear axle hangers – usual stuff. Sadly complete shells aren’t available yet from British Motor Heritage, but a lot of the individual panels are. Mechanically, the engine is robust although, while it’s based on the detuned Austin 3-litre unit, items like the valve springs and sump are unique to the MGC. The biggest weak spot is the piston and rings, plus the rocker assembly, all of which wear quite quickly. But it’s the gearbox which is the real problem as it’s not really up to coping with 170lbft of torque.

You think you know the 50-year-old MGB but the MGC featured many unique parts – have lesser or perhaps modified MGB bits been used over the years, to ‘bodge’ an MGC? The good news is that you can’t make and fake an MGC; specialists who have tried to convert a B into a C say that, because the front structure is so different, it’s simply not worth the time, money and bother. So don’t try it either.

Hotting one up

Equipped with twin 1.75in SUs and a Weslake designed 12-port head, you’d think that the MGC could breath easy but, in fact, that’s one of its biggest maladies. For those on a budget, freerflowing air filters is a good, cheap first step. Once more air is getting in, extracting it more efficiently is essential and there are numerous companies marketing sportier systems – try Moss or MG Motorsport (who helped enormously with this feature) for starters. The latter outfit sells Downton style manifolds (£511) and complete exhaust set ups (£350). All this should eke out a welcome extra 10-15bhp.

For mild tuning the standard SU carbs are more than up to it by way of rejetting if in good order. For more extreme tuning there’s the potential to fit triple units; Moss sells a dedicated inlet manifold for under £400 – and you can add another grand for new SUs. An even pricier possibility is triple Weber DCOE which Hertsbased MG Motorsport (01442 832019 – www. mgmotorsport.com) sells for over £1800. Pricey but these are only really called for if the cylinder head has been extensively reworked – which this old fashioned non cross-flow piece of iron needs to be ideally!

Despite the famous Weslake name, there’s a lot of hidden horses in those combustion chambers waiting to get out. Any good tuning company (the MG owners clubs will be able to help here) should be able to carry out a Stage 1 or Stage 2 modified head. MG Motorsport says the standard valve sizes are already massive and it’s only the porting department that needs redressing. A stock lead-free head costs some £600 while a reworked tuned one starts from just under £1000.

A hairier camshaft really helps the engine rev – MG Motorsport uses a Kent cam design. Remember that there’s some original period kit out there by way of the likes of Oselli, Downton and even BLST (British Leyland Special Tuning). Downton. University Motors, made some special run-out triple carb MGCs, kicking out 175bhp, while today 180-185bhp is the norm.

Even with balancing and lightening the big block never going to be a high revver, although a lightened flywheel, costing just over £100, really improves throttle response and is a good swap, even if you only intended to replace the clutch, says MG Motorsport. Gearbox ratios varied during production, with early non-overdrive cars having the same spec as the MGB. Cars with overdrive featured a sturdier close-ratio gearbox but, during 1968, all cars were fitted with this unit. Differential ratios also varied, plus a limited slip diff was one of the options when new. Non-overdrive cars featured a 3.07:1 ratio.

When new, the MGC could even be specified with a ZF limited slip diff and a closer set of gear ratios. The best option today is fitting the evergreen Ford Sierra Type 9 five-speed ‘box but this as a complete kit leaves little change out of two grand. MG Motorsport sells different gear sets for the MG transmission, while the overdrive can be uprated to competition spec.

There’s now also the choice of a Salisbury LSD or a more modern torque sensing diff or an exotic Ford rear axle, along with Ford-sourced IRS, from Surrey specialist Hoyle Engineering. Depending on what you opt for, you’re looking between £900 and £2000+.