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Modify your MGB Pt2
Thursday, 19 May 2011 15:38

The performance, handling and braking abilities of your MGB can be modified to match those of more modern sports cars. We look at what products are available and how much they cost.
Report by Rob Hawkins



In the last issue of MGE, we covered the comfort, styling and practical modifications that can be made to the MGB to bring it up to date with modern standards of comfort and convenience. This month, we’re looking at the performance improvements that enable these cars to go and stop faster.


The MGB has evolved in the traditional manner of many classic sports cars, where everything from uprated brakes and suspension to engine transplants have been developed. Thanks to the popularity of the model, a wide range of specialists have contributed and consequently there is a wide choice of modifications to consider. With such a vast array of options available to the MGB owner, there’s no single correct direction for improving your car in relation to your budget. You can change a lot for £500, or just one component for £3000. However, it’s easy to get carried away and spend a five figure sum, whereas a good starting point is to make sure any standard components are in good condition. For example, if you wish to improve the handling of your MGB, make sure the tyres, stub axles, steering components and any suspension parts you don’t want to change are all in good working order.


The MGB modification market isn’t standing still, even though aftermarket improvements were underway when the car was being manufactured and you’d think that after nearly 50 years, the limit of improvements should have now been found. However, many specialists are keen to progress and are looking for new ways of improving the MGB. Frontline Developments have become well known for their K-series engine conversions. MGOC Spares and Clive Wheatley are some of the specialists who have continued the campaign for the Rover V8. Hoyle Engineering has developed an IRS and Moss have stuck their neck out with a supercharger conversion, while a quick trawl through the MGB Hive’s website will tempt you with a wide range of upgrades. There are many more specialists and achievements, so the following sections aim to provide an overview of what’s available.



The MGB’s 1.8-litre cast iron overhead valve B-series engine may seem asthmatic in comparison to modern twin cam engines of equivalent capacity (the B-series produced a sub-100bhp output in the MGB, whereas the MGF’s twin cam K-series produces 115bhp even in 1.6 guise), but its tuning potential can help transform its performance capabilities.


Traditional upgrades start with a performance air filter from the likes of K&N and Pipercross, but if your budget will stretch, uprate the fuelling with a twin HS6 SU carburettor kit for £600-£700 or a single 45mm Weber kit for a little more. The exhaust system can be similarly uprated to help the engine breathe, with free-flowing manifolds and systems for around £400. If fuelling and exhaust upgrades are not enough, then the next stage is a performance camshaft in fast road spec, which can shift the power band and allow the engine to rev higher (prices vary from £120 and are cheaper if your old camshaft is re-profiled). Similarly, the cylinder head can be re-worked to increase airflow and performance. Some MG specialists can do these modifications to your own cylinder head, whereas others sell brand new modified heads with new valves, springs etc for £700-£800.


All of these modifications can increase the performance of the B-series to 100-120bhp. If you want to go further, then an aluminium crossflow head from Webcon for £1050 will see greater improvement along with a host of further fuelling and ignition modifications, but another approach may be to increase the engine’s capacity. Popular big bores for the B-series include the 1860, 2000 and 2100cc engines, which are available from many MG specialists and can offer power outputs that are almost double that of the MGB’s first B-series motor. Budget for around £2000 for such an engine, and keep some funds aside for any ancillary upgrades.


If, however, you don’t want a new engine but still want an impressive performance gain, then Moss sells a supercharger conversion kit for the MGB’s standard B-series for just over £3000. Providing the engine is in good condition, expect power gains of around 40%.



Aldon Automotive 01384 572553
Beech Hill Garage 0118 9884774 
British Motor Heritage Ltd 01993 707200
Brown and Gammons 01462 490049
CCHL 01482 441551
Church Square Autos
01932 241843,
Clive Wheatley
01746 710810
Croydon Classics
08000 556155,
David Manners
(Abingdon Parts for MG) 0121 544 4444
Don Hoods 0121 3731313
EJW Sports and Classics
0777 448 4497,
Fisher Services
020 8776 7695
Frontline Developments 01235 832632
H&H Ignition Solutions 01384 261500
Hall’s Garage 01778 570286
Heathrow Transmissions
0208 577 1505
Hi-Gear Engineering
01332 514503
Manor Garage 01235 767751
Merlin Classic Cars 01663 746499
MGB Hive 01945 700500
MGOC Spares 01954 230928
Midland Sports and Classic 01905 621331
Midland Wheels 01926 817444
Moss 020 8867 2020
Oselli 01993 849610,
Paul Depper MGs 01543 376222.
PJM Motors
01630 652873,
Prestige Autotrim 0151 643 9555
Rees Bros 01252 323038,
Rimmer Bros 01522 563344,
SC Parts
01293 847200  
Surrey Sports and Classics 01483 223830
Sussex Classic Car Parts 01403 711551






To read more about this project see the June 2011 issue of MG Enthusiast.

Back issues of MG Enthusiast available here

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