MGB

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Do you drive this great classic or are thinking of buying one? Here’s how to ensure that you get the best out of your car for years to come

If there’s a friendlier classic to own and maintain than the evergreen MGB then we’ve yet to meet it! Thanks to the orthodox mechanicals which are little more elaborate than a Morris Oxford, the rubber bumper MGB is a brilliantly easy car to keep on top of maintenance-wise, requiring little more than a basic workshop manual, toolkit and a grease gun. And if you are not keen on DIY then there’s an army of specialists who will do it for you – many who have developed useful upgrades and dodges over the decades to a rubber bumper car sparkle like the earlier chrome classics!

1. Engine output

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Anything from 105-130bhp can be coaxed for road use; better breathing with head and exhaust as r/b model suffered detuning in these areas. You can see a 40 per cent hike by supercharging but it costs £2000, around the cost of a cross-flow cylinder head conversion. If you don’t want to go the V8 route, the Ital-sourced O-Series and later K-Series engines fit and work well.

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Pre-ignition can be a problem and hard to dial out; valve seat recession affects head more than most so use a fuel additive if you drive hard. Cooling system went to V8 spec in ‘77 and worth updating to. These engines can become tappety but it’s rarely dire, unlike crank rumble. If the rockers are worn you can swap with roller ones which act like a sportier camshaft.

2. Bottom end

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The robust B-Series (also used on other BL cars and vans) can be taken out to 2.1-litres for more torque but 1950cc is easier and cheaper to attain. It’s worthwhile having the crank and rods balanced plus lighten the heavy flywheel to improve throttle response but it’s not a high revving unit anyway unless you go for exotic crankshaft and con rods to suit. Tuned 1950cc engines cost from around £2200.

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The five bearing B-Series is more robust if not as free revving as earlier unit but plentiful; many MGBs were fitted with Marina TC engines over the years. Low oil pressure on any B-Series is usually due to general wear and a failing oil pump. The sump can be dropped in situ for a quick repair but alas not all main bearing caps are accessible – the engine has to come out with ’box attached to do it properly.

3. Transmission

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Higher overdrive gearing really helps the MG when touring. Five-speed conversions always popular but as Ford Sierra ’box supplies dry up others are being tried. Vitesse, in conjunction with Mazda, has launched an MX-5 kit that’s said to be better and cheaper than Ford conversion requiring no structural mods plus there’s a six-speed option, although clutch slave cylinder has to be relocated inside the bell housing.

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Overdrive unit rarely gives trouble. If it has become lazy, then it points to low lubricant or an electrical switch/solenoid fault but the latter are swines to renew. MOSS produces an overdrive upgrade to cope with tuned engines that costs some £400. Most ’boxes become noisy but more an irritant than an ailment and rarely terminal; try a special oil or additive first. Replacing clutch requires taking the engine and ’box out.

4. Front suspension

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Take care that you don’t go too hard and make ride intolerable; telescopic conversions work well for road use but ultimate is fitting a complete R V8 front axle. Other alternatives include MGOC’s Evo3 alternative or the Hoyle kit – all in the region of £2000+ mind. Choice of anti- roll bars but speak to a specialist to see what’s best after lowering. PAS kits are available while the rack’s ratio was changed in ‘76 to allow a smaller steering wheel. Castor adjustment kits not essential on r/b models as it’s already done at factory although can still be improved upon.

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Trunnion and king pin wear out so their condition is a safety issue as they can fail with dangerous results. Regular lubrication is the key; EP90 gear is recommended but 95 per cent use grease instead. If you need to replace a trunnion it’s best to renew the pair at the same time. Wishbone bushes age and collapse but are straightforward and inexpensive to renew; use the tougher, tauter V8 ones when it comes to replacing them even on standard cars as will last longer. If staying with lever dampers, beware that cheap recon ones don’t perform or wear as well as standard stock replacements.

5. Brakes

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No shortage of mods, but just a set of uprated discs and pads suffice for most after a thorough service (EBC are good bets; pads just £38). Rear discs brakes are possible but more a luxury for road use; try Alfin drums before going this route. R V8 front axle boasts the best set up while slightly modified 2001-06 MX-5 vented front anchors are now being fitted with success.

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The MGB’s brake system couldn’t be more orthodox and so is simple to keep in tip top shape. It’s wise to keep the rear drum adjusters well lubricated as they can seize and affects handbrake too. If the diff’s breather is blocked it spews oil over the linings. Dual circuit brakes were fitted for 1977 and it’s a wise alternation to fit these days and not hard or expensive to do either.

6. Body and chassis

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The great thing is that every panel is available, right down to new nine grand bodyshells, from British Motor Heritage and quality has improved greatly over the years. Swapping rubber to chrome bumpers isn’t half as easy as it first sounds and can cost up to £600 (MGB Hive) to do properly (many haven’t), with new parts, yet doesn’t add to the car’s residual value, only vanity.

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Rust is the biggest worry along with past repairs. Softening inner wings is common (carry out a ‘press’ test) along rotting floors and suspension points. Sills are a major concern and must be fitted with accuracy and this can involve removing the wings. If not, the doors can clip the body, especially on GTs.

7. Rear suspension

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The ideal solution is to ditch the old fashioned lever arms in favour of a telescopic conversion for better damping. It’s a straightforward and inexpensive job as dedicated kits are readily available. However, it usually makes the ride extremely hard. More exotic modern style rear end formats are available from the likes of Frontline Developments and Hoyle, but at around £2000, depending upon kit unnecessary for most road going owners.

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Lowering a r/b model is a bit of a compromise as the leaf spring attachment points were altered so you can’t simply pre-’74 suspension – simplest mod is to use lowering blocks. Ensure the right springs and roll bars are used or the handling will be worse than before. Leaf springs are prone to settle with age; if you prefer comfort then most fit £200 modern parabolic replacements.

8. Wheels and tyres

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MGBs used 14inch wheels all its life. Today, unless highly tuned, a moderate but good quality 185/70 profile is the best all rounder for grip and ride but steering will still be heavier. If you want something different to the norm a variety of production wheels also fit, such as TR6 or Scimitar GTE rims. Keeping it in the family, you can also fit MGR rims which are 17inch but it’s doubtful if standard suspension cars will accept them readily.

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Wire wheels look the business on any B but bear in mind that original MG items were 1/2” narrower than the standard steel wheels so can’t take wider modern rubber quite as easy. Converting to wire wheels is simple once you have the necessary hubs or you can simply fit V8 alloys, which were fitted on last-of-the-line cars. MGR rims allow the lowest of profile tyre options but speak to a MG specialist first before you do.

9. Panels

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Virtually all you need to make an MGB showroom fresh is available and quality better than it was new. Chrome bumpers must include all the mountings and valances to make it look authentic which some conversions lack. Many then opt for early type grille but it looks completely wrong on a W-reg!

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Know your MGBs. While they all look much the same, subtle differences were regularly effected. That 70’s cabin trim decor can be discarded for something more classy and classic but changing the dashboard and later rocker switchgear is a lot more involved.

Rubber erasers

Most folks dislike the rubber bumper looks but there’s other ways to erase them than refitting chrome ones. RPS (Revolution Performance Sportscars) offers a smart Sebring-like conversion that also goes as far as an racingstyle dashboard option. New for 2017 is the outfit’s revamped VeeBee wing for a much smoother look at less than £300 with the mesh grille. Other options include ripping off the bouncy bumpers and fitting fibreglass valances from as little as £70.

And another thing…

Even on a standard MGB consider fitting an uprated radiator if it needs renewing as cool running helps prevent valve recession. Electronic ignition and a rolling road tune up are wise steps before any further performance tuning is carried out and go to somebody who knows their MGBs for this as experience counts. There’s shed loads of period tuning gear around from the likes of Janspeed, Downton and Oselli if you want to keep the car nicely in period. V8 conversions are common and there’s plenty of books on the subject but it’s more involved than you think if you want to do it right. You can also go diesel with a Sherpa van engine and get 60mpg – but slowly!