Get more from your B...


Period Tuning

For the average classic MG enthusiast, the B more than delights, it is like a time machine allowing us to enjoy motoring 1960s style.  A well maintained MGB will reward with reliable running, whilst still holding its value.

But too often we grow old with our cars, not realising how worn they may have become.  Or worse, we buy a smart example with a fresh coat of paint, but tired mechanicals and believe this is how they performed when new.

Today’s roads are crowded; fill of impatient motorists not in the least interested in our fascination with classics, there’s no forgiveness from the modern motorist for our slower classics.  Safety suddenly seems to be lacking.  For some, the lack of performance and handling starts as a disappointment, becomes an irritation and ends up in a clichéd slating of the MGB, Top Gear style. 

So what to do?  Some fit bigger engines and expensive suspension systems.  Others move onto more modern cars.  But what if we want the best of both worlds?  Improvements that put the MGB back on a level footing with the modern hatches whilst keeping it all original?

Hopefully in this article I can introduce you to some of the ideas I have used to good effect and that are to be found on this website.  Whilst at first glance the website is about upgrades and modifications, it is also sensitive to keeping the MGB original where it can.  I am an inveterate tinkerer, and I like upgrading because a part of me wants to challenge the original design, but I also know that the engineers of the original car also knew a lot more than me and invariably had it spot on within the bounds of the commercial aspects of selling a car.  Not for nothing did the Special Tuning department exist to help get more from the MGB, and to drive a modified car in keeping with the period tuning modifications is a revelation over standard cars, especially tired ones.

When I first got back to owning an MGB (a 1980 GT) in 2002, I made friends with fellow member local to me, Phil Earl.  He had a philosophy of always returning everything to the way the factory intended so that he could explore how well the car then performed before venturing onwards to more expensive upgrades.  Both of us were often tempted by the seemingly endless choice of aftermarket, non-standard packages available for the MGB.  However specialist MG magazines would often heap praise on these modifications drawing comparisons unfairly, we often felt, based on standard, but tired cars. 

If you were comparing a revolutionary suspension against a factory fresh suspension, would the financial outlay seem as worthwhile by comparison to a worn standard suspension system?  What would it cost to get the standard system restored, and mildly improved to Special Tuning standards against the outlay for an all-singing-all-dancing aftermarket set-up?  How different would the two be afterwards? 

So www.upgrades4mgs.co.uk was set-up to explore whether standard could be achieved on a budget, and yet be as good as the expensive aftermarket hardware. 

Over the subsequent 7 years I modified my 1980 MGB GT in a number of ways and made it very much a car that could be used on a daily basis in modern traffic conditions.  However, it was no longer visually standard.  Having moved on from that heavily modified 1980 MGB GT to a very original 1966 MGB GT, I am now asking myself how can I achieve the same performance gains without affecting its visual originality?


I started with the engine working on the 80/20 rule; getting 80% of the improvements for 20% of the potential spend.  The great thing about modifying the engine is it will still look standard on the outside.  Don’t be shy to go a little wild here and get as much power as you can from the venerable B Series.  I actually started with a worn clutch but you know how it goes, you pull the engine to change the clutch and one thing leads to another.  For about £350 more than the cost of a standard rebuild, I had the following work done to improve the performance of my B Series;

You have to remember that unlike modern cars there is a lot more untapped potential in older engines.  As a result of the above work you are looking at a reasonable gain in power and torque.  Some owners don’t like to go as far as 1860cc because this is the limit for rebuild on standard oversized pistons, but others go beyond this to 1950cc or even 2100cc.  But at 1860cc at the limit you keep the costs down on both the pistons and the machining.  A stage 2 head will breathe much better, but it won’t cost a lot.  Most rebuilds will entail having the head converted for unleaded anyway, so the extra work here is not a huge cost.  Of course bigger valves etc depending on the age/specification of your engine will help, too, but at a cost.  If the head and block are being skimmed you may as well increase the CR.  The likelihood is you will be spending on a new camshaft, too, so fit a mild fast road one, too, for the same money as a standard cam shaft.  You can go for a wilder 715 or 717, but I was advised to stay around 714 in order to keep the engine useable at low revs in town.  And for not much extra cost, get it all balanced, you will be amazed at how smooth the engine is afterwards, I often hit 6500rpm with my modified ignition system and even on a standard distributor system it felt smooth all the way through to 5500rpm.  I could also get the engine to tick over at an indicated 500rpm it was that good.

Of course, if money is no object, consider a period cross-flow head and Weber carburettors to top it all off for an 180bhp beast.  Or fit a period Shorrock supercharger for a lot more low down torque.  But these modifications start to enter the 20/80 zone, meaning a huge spend for little gain.  In addition you are starting to venture outside of the original look in the engine bay, and playing on the edges of reliability and short engine life.

See: Engine Tuning

It goes without saying though that there are two other aspects to a more powerful engine; fuelling it correctly, and igniting it on time.  Finding a local rolling road will pay dividends in getting the most from your engine.  If the owner is knowledgeable you will be surprised at the difference in performance that they can extract by interpreting the figures and tuning it accordingly.  Depending on the rates expect to spend between £100 and £150 for their time.  Also, if your local MG group can’t recommend a good rolling road operator, talk to the classic Mini brigade as the A Series is not that different with twin SU carbs etc..  

With respect to the carbs, all I did on mine was to buy a cheap set of HIF units on Ebay for £10 and then rebuilt them using a Burlen kit for around £60.  However, the HIFs are easier to rebuild having dust seals that will have prevented wear on the throttle spindles.  If you have HS units, you may need to get a professional to bore, ream and re-bush the carburettor bodies.   Most people struggle to get old HS carbs set up because air can leak passed the worn spindle bushes.  On the HIF carbs, these have an emission valve on the throttle plate and a subtle, hidden upgrade here is to fit the HS throttle plates without the valve.  An immediate improvement is the better engine braking as you come off the throttle.  Also, setting up the idle will be easier as often the emission valves wear and allow air through at idle making it difficult to get a low enough idle speed.  Whilst you have the engine built consider port matching the inlet and exhaust manifolds, too.  Once you have the carbs in good working order, fit some freer-flowing filters.  Avoid the cheaper, flat pancake type filters.  If you want to stick with original looking parts, fit the K&N elements inside the original Cooper cans.  Or if you are happy to have open filters, make sure you use the deeper K&N on the standard base plates as these are properly radiused to give a smooth airflow into the carb mouth.  Don’t waste money on trumpets, they are not needed with the original base plates.  With the extra air flowing through the carbs, it may pay to go for a richer needle in each carb.  A typical guide is to use AAA on the HIF, but as with the ignition, find an old school rolling road where they know how to profile the needles or at least carry a stock of different profile needles to try.  I also invested in a Gunson’s carb balancer and CO meter which helped me set up my carbs such that on a rolling road session there was no more power to be found from them, so if I can manage, don’t be afraid to have a go yourself at setting the carbs up.

See: Carburettors

Don’t forget with all that extra air going in it needs to escape.  However, the standard cast iron manifold is perfectly good, I think.  A stainless steel one needs to be good quality as I have found some to be awkward to fit.  Several noted tuning experts also suggest avoiding the exhaust wrap as it traps the heat which is perfect for avoiding warm, thin air going into your carbs, but not good for the head and manifold.  One thing I always meant to try was ceramic coating on the inside and outside of the exhaust manifold which is deemed better as the heat escapes more readily down the pipe rather than soaking into the manifold.  Removing the centre bomb box can help, but it can also make the car noisier.  I’d also avoid stainless systems next time as I find them too raspy and tinny compared to mild steel.  But if you can, fit a slightly bigger bore pipe work.

As to igniting it on time, there is nothing quite like a worn distributor to upset the dwell and subsequent smooth running.  Also, tired HT leads, coil and plugs won’t help.  Buy a new distributor, coil, leads and plugs; it’s not expensive, but you will be amazed at how smoothly the engine will run, and starting will be improved, too.  Make sure you get the correct model for your engine but if you want to tweak it find an old school rolling road man and play with the bob weights and springs to get a better advance curve.

Whilst keeping the ignition standard and thus the period look, the sad reality is that modern service items are not to the standard of the originals so there are various standard looking options such as the 123 and other electronic options that hide under the distributor cap.  Various forum related stories suggest that these can work well and give many years of service whilst others complain of sudden failure.  In addition there can be issues with getting the rev counter to work with the more modern electronic systems, but that can easily be overcome by getting the rev counter upgraded and calibrated, again a hidden modification.  It has to be said that the options where the electronic bits fit to the existing distributor has its limitations if the distributor is worn so investing in a new distributor may be necessary.  I am a fan of modern electronic ignition units as they eliminate the need for regular attention to setting the points gap, aid starting and maintain peak performance between services, whilst producing a fatter spark and helping extend the plug life.  I have also dabbled with a home brewed Electronic Distributorless Ignition System (EDIS) taken from a Ford, but it must be said this is very much in the non-standard league as it requires not only more effort to fit, but requires a trigger wheel and sensor, throttle position sensor (TPS) and ECU to be fitted, all of which are very much evident under the bonnet.  That said, having the ability to plug in a laptop and play with the advance is very much appreciated, and a rolling road session on my engine on a standard new distributor against the EDIS saw 10bhp more at the back wheels.  But it fails the originality test in terms of the engine bay look.

See: Ignition Systems

Lastly, put some decent petrol in the tank.  If you have a local garage selling leaded fuel, support it.  If not then I have always found, and this is supported by numerous others, that Shell Vpower Super unleaded is the best for the B Series.  I covered many miles on my rebuilt engine and the higher Octane allowed better advance, I had little or no run on and I never used aftermarket additives, which you don’t need if you had the head converted to unleaded.  The Vpower seems to also help keep things much cleaner where it counts.

See: www.oils4mgs.co.uk


I have probably put the cart before the horse.  I should probably have started with the brakes and the suspension.  After all, it’s about Safety Fast!  Looking at the brakes, I am inclined to think that if you can lock up your wheels then the brakes must be good already, right?  Well, that assumes you have new or fresh tyres.  Old tyres are dangerous.  If the tyres are over 5 years old, get them replaced.  The rubber hardens and grip is lost.  Also, buy quality tyres, not cheap Far Eastern imports with poor grip and tread design.  Then make sure the wheels are balanced and that the alignment is set up correctly.  On these last two points, most modern tyre places need some guidance, so go prepared.  If you have RO-style rims, ask them to balance them using the 4-stud adaptor and not the central cone as the wheel centre of the rim is often eccentric.  Then let them know it is rear wheel drive and that the front tyres must be toed-in, not toed-out, between 1.5 and 2.5mm.  Mine were set at 2.0mm and balanced accordingly, and it made a big difference to the smoothness of the car and the lightness of the steering at parking speeds despite having wider 185/70 14 tyres on my RO-style rims.  A lot of people opt for the Minilite replicas but be aware cheaper ones are not to the standard and quality of the genuine Minilites.  There is also a tendency to fit 15” rims but remember that you will lose some tyre wall height and thus gain a harder ride.  However, the 185/70 14 is an ideal tyre for the B being more easily available than the 165 14 which is more commonly sold as a commercial tyre and thus not as good for going that bit faster.

Back to the brakes, if you can still lock up the wheels, all is good, but learn how to cadence brake as ABS was not an option!   People often ask about fitting a servo, but the reality is a servo is correctly known as servo assistance, and does not improve the braking performance, it merely assists with pressing the brake pedal, i.e., reducing leg effort.  If your braking system has not had any attention for some time, consider new all round; master, callipers, wheel cylinders and of course pads and shoes.  And don’t forget fresh fluid once a year if not at least once every two years.  DOT5 Silicone brake fluid is an option but I suggest for more information have a look at another of my websites, www.oils4mgs.co.uk.   Suffice to say there are those that rate DOT5 and those that don’t, but I liked it for being able to leave it in longer, and not having to suffer the paint stripping properties of DOT4.  Be warned, you really need new everything in the brake department before using it and it will leak more readily from the pipe unions.  Also, it is purple and therefore fails the originality test again if you have a clear plastic reservoir.  Standard discs and pads can work well, but the more expensive options I found needed a period of warming up before working well, and were, frankly, useless when cold.  Thicker discs and bigger pads can be bought to help the braking effort, but again it comes back to the road surface conditions and if it’s wet bigger brakes will get you into a slide quicker; modern cars have spoilt us in that regard.  Read the road ahead and try to avoid scrubbing off speed.


Which brings me to the suspension and I am probably going to be challenged for this, but in my opinion there isn’t anything wrong with the standard suspension design, even for the tuned B Series engine.  Sure, if you’re thinking of a V8 engine, then yes, the chassis is limited, probably.  I agree that there’s room for improvement, but this is easily achieved on a budget.  The B handles beautifully on a stiff front end and a flexible rear.  So at the front, having made sure the steering track-rod ends, kingpins and bearings are in good order, then fit a stiffer anti-roll bar. Fit reconditioned lever arm dampers (they’re not shock absorbers, that is the spring’s job).  Recon dampers are cheap but try to get a set that match in terms of resistance to movement.  Many are sceptical of the quality of reconditioning on the cheap recon units so invest in a better quality set of recon units from the MGOC or buy new ones.  Then fill them with thicker oil.  Some say that thicker oil is not the right approach and a replacement valve should be fitted to stiffen the damper.  Your choice; I used thicker oil.  As to the springs, the normal poundage rating is, I think, adequate but from experience, I would recommend you avoid the higher rated units which will be too uncomfortable.  On a chrome bumper car, there may be some benefit to fitting lowered springs but beware the sleeping policeman and your exhaust.  On a rubber bumper car, there is every reason to fit lowering springs front and back.  There is an immediate improvement in the handling.  The free length of the standard rubber bumper spring is 10”, and I fitted chrome bumper front springs with a free length of 8.5”.  The rubber bumper front cross member hinders getting the car as low as a chrome bumper car but even so the resulting looks alone are worth dropping the 1.5”, never mind the better handling.  Also, on a r/b car, the lower springs induce a slight negative camber also helping to improve the handling.  Negative camber arms can be bought for c/b cars but be aware, we found that on a 1972 car this induced too much negative camber, so I have always been a bit weary of these since.  Also when lowering the front, you will need to fit modified bump-stops as the lower suspension pan will be sat closer to the stop and reduce the suspension travel on a really bad bump resulting in a nasty crashing through the bodywork.  Lastly fit new bushes.  Some recommend the V8 version, but I used the fast road poly bushes that are readily available.  These have less give and stay fresh for far longer helping to reduce the flex in the system when cornering. 

At the back of the car, the cheapest and quickest route to lowering the car is to use lowering blocks.  This is useful on a rubber bumper car if your springs are ok.  Some of the new leaf springs are of questionable quality so if your springs are ok, keep them, but fit new bushes.  Also, leave the springs to soak in oil overnight to help them lubricate; the leaves slide over each other and should have an interleaf ‘plastic’ material to prevent friction from surface rust (note: if you have rubber bushes in the springs prevent oil getting on these).  When I changed my back axle I soaked my springs and the improvement was very noticeable with much less crashing and jolting at the back.  You can also wrap the springs in a strong ‘Denso’ tape to help prevent water and dirt getting in, but I didn’t, and some say this trap moisture inside, although that should not be an issue if the springs are well lubricated).  I have seen an adaptor offered years ago for a grease gun that enabled you to pump grease into your springs to refresh the lubrication.  I am not going to mention much on parabolics; the few cars I have been in have been a disappointment for me (personal opinion only), but others seem to like them.  However, they’re obviously in the non-standard league, and require telescopic dampers.  Frankly, again the standard lever arm is adequate in my opinion and a leaking damper is not an MOT fail, but a non-working damper is.  So don’t be afraid to use the lever arms and save your money.  Telescopics are often reported to be too firm, anyway.  On r/b cars the later models from 1976 on were fitted with a rear anti-roll bar.  When lowering the back the anti-roll bar upsets the balance and can lead to sudden oversteer.  As my rear anti-roll bar had a failed bush that was causing a knocking on the body work, I removed it and it gave the car a slight tendency to safer understeer.  I’d recommend removing it, but at first it took some miles getting used to this as the car felt slightly squirmy at the back, however, I gained more confidence and found the car handled better as a result.

See: Suspension upgrades

Other Upgrades

A few other nice upgrades staying within the originality theme, whilst improving safety, include the use of electrical relays.  The headlights will benefit from being supplied by a relay for starters.  But fitting halogen units will also improve the output.  Apart from the fact that the lighting switch in the car will be safer and last longer by not carrying such a load, many have found that the instrument lighting is also improved.  In addition, it’s possible to fit LED lighting in the instruments such that these are LED strings are hidden behind the bezel but improve the lighting for night time driving.

See: Lighting

For owners of the r/b cars, a relay on the electric fan is a good idea, too, as well as for owners of GTs with heated rear screens.  The relays can be hidden under the dash and the extra wiring lost within the loom covering.

In terms of entertainment, vintage and period looking radios can also be modified to take an input from a modern music player.  The speakers can be hidden behind period looking grilles or mounted under the dash out of sight.

See: ICE

The standard seating is comfortable but can also lack grip in cornering.  Whilst I managed to fit MG ZR seat foams and covering with a lot more bolstering, this is non-standard, but a subtle building up of foam under the original seat covers can improve the grip of the seat a little to hold you more firmly, whilst still looking original.

See: Seats

Owners of the rubber bumper MGBs often change to chrome bumpers using the numerous conversion kits available.  Obviously this is not original, but mimics originality using a later car.  Therefore I think it should also be mentioned that there are two other options for r/b owners that want to improve handling or looks yet staying with the realms of period looks or period tuning.

The rubber bumpers (they’re not really rubber) have a solid steel armature which is significantly heavy, and can influence the handling being mounted so far out at each end.  One option is to mimic the Sebring cars by using the valences in place of any bumpers as I did on my 1980 GT.  As period looks go, this is more a period weekend racing car look than an originality look.  Some go further and use the larger wheel arches for the full Sebring look, although this really needs to be matched to a more powerful engine.  The Sebring cars are more normally associated with MGC GTs, although the first Sebring styled Special Tuning GT one was a B Series, I believe. However, keeping to the theme of originality, r/b owners can opt for fibreglass replacements without the armature and thus improve handling and reduce weight, whilst still looking original. 

See: Losing the rubber bumpers

The MGB is what it is and despite all of the above it is still a nearly 50 year old design.  One cannot make a silk purse out of a sow’s ear, but that said, the MGB is no pig, and in fresh condition mechanically with a few sympathetic upgrades, there is no reason why it can’t be enjoyed in the company of more modern cars.  Have fun! 

PS. Walnut dashes are not original; they don’t belong in sportscars.   If you want a wooden dash, buy a Triumph!



If you are looking to sharpen the handling, and score a bit more power, but you think the performance improvements may spoil the originality and character of your B, then read on here for some hidden gains.

Keeping your MGB original, but modifying it.