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MG MGB Technical - Best MGB (long thread)

Evening All,

Ive been sent a (hard) copy of an article that appeared in a now defunct magazine, published in 1989. It concerns the MGB of Ron Gammons, which he is still successfully campaigning today. Given how old MGBs are, and that probably little has changed on the car described, I reckon its still pretty relevant today, so I thought Id scan it and share it with you. I recommend pasting it into a word doc. and printing it off for reading at leisure.

Title: King B

Intro: >>Its been competing since 1966 and this year alone it won the Pomeroy Trophy and finished fifth in the Pirelli Marathon. Its also immaculate, which makes it arguably the best MGB in the world. Mike McCarthy drove it, and owner Ron Gammons tells you how to make one just like it.<<:

I must confess that the MGB didn't do a great deal for me. A Marina in drag, that sort of thing. Ok if you want an ordinary rather boring and banal open sportscar, but not made of the Right stuff.

But I began to think twice after the Pirelli Marathon this year. Actually, I began to think twice during the Marathon, especially when Mr Stirling Moss in an MGB kept storming past with monotonous regularity (I started sixth, he started seventh). At first I put it down to his talents and not the car. But then at the end, when MGBs finished third, fourth and fifth, I began to wonder just a little. Could it all be due to driver splendour? Messrs Tony Dron and Ron Gammons were the conductors of the fourth and fifth place cars, and are no mean drivers, but there must be something about the machines themselves. Indeed Ron had prepared Mr Moss's car. What's more, I remembered that he had won the Pomeroy Trophy this year in the same car he took on the Marathon. There must be more to the MGB than I thought.

There is a damn sight more. Mind you, Ron's car is a rather special MGB, but there's nothing so special that it can't be done to any MGB. And therein lies the change of heart. Mind you, Im still not sure about the average, 100,000 mile secondhand ill used banger, but then I suppose that applies to any car, not just the MGB.

This MGB started life on the Abingdon assembly lines between 17 and 20 December 1965 (so it's just eligible for pre 66 events) and was registered JYH 770D on 1 February 1966. It was bought by Richard Worts, who sponsored Richard Bunce. It was handed over to the well known MG tuner Bill Nicholson for preparation, and almost immediately stolen from Bill's shop and wrecked! It was therefore reshelled and rebuilt by Bill.

In February 1967 Roger Bell of Motor magazine put it and Bill's sister three bearing car through their paces at MIRA. It was fairly extensively modified, with a stage six head (costing all of 335!) for example, and lowered and stiffened suspension. The acceleration figures were pretty remarkable. 0 60mph in 8.0sec as against the s B's 12.6sec, while the 70-90mph time dropped from 14.8sec to 8.1sec. Later that year, in August, Nicholson entered Bunce at the International Race Meeting at Brands Hatch: David Piper won overall in his Ferrari 250LM, but in class B (1600-2000cc) the order was Tony Dean, Porsche 906: John Morris, Porsche 904; Don Bunce MGB; Bill Bradley, Porsche 906. Not bad for a cooking sportscar.

Bunce kept JYH until 1971 when it passed through a couple of hands before being bought by Barry SiderySmith (whom Worts had sponsored in 1964 and 1965). Barry added considerably to its lustre, entering it in over 200 club and marque races between 1971 and 1983, still looked after by Bill Nicholson and basically in the form in which Bill prepared it for Bunce. He had considerable success with it, and it became quite famous in MG racing history. When Barry started the MGCC B-C V8 Championship in 1977 he entered JYH and promptly won the Championship that first year! For these events he added slicks to JYH, plus some careful wheelarch widening.

When it arrived at Brown and Gammons it was as it had been modified by Barry, with wider wheelarches and very sound underneath. Ron took it back to original standard steel wing form but did fit a 1950cc engine (basically an over bore) to suit the B-C V8 racing series. It so happens that this is the minimum capacity for the Pomeroy Trophy as well, so he swopped his usual mount, a V8, for the B and in his first attempt won a second class award, in his second a first class award, and this year won it outright (by 0.41 marks out of 437!) from Rodney Felton's Alfa. The standard capacity 1840cc engine was then replaced and Ron entered it in the Marathon, finishing as has been mentioned fifth overall. It was also taken to Zolder and the Nurburgring for the historic races, in rally trim but with a racing cam. That was the form it was in the day we drove it.
The 1840cc engine is kitted out with a high compression head and that full race cam, but the rest - crank and rods, for example is basically stock. There's a special distributor and a 45DCOE carb bolted onto it. The gearbox is a full synchro, close ratio, straight cut gears unit, while the rear axle is a banjo type which in MG folklore means the ratio can be easily changed. The front springs and dampers have been uprated to 600lb, and 25 per cent respectively, but the rear springs have been left basically quite soft. The interior is fully trimmed, complete with carpets, but there's a roll bar which Ron regards as essential if you're going to indulge in any sort of competition. Theres a hardtop for two reasons: the first is that it hides the roll bar, which Ron thinks looks ugly on an open car, and the second is comfort. Wind in the hair is fine for an hour,
maybe a day; after two days it's exceedingly tiring and after four youre knackered. Then there's the rain: soggy route maps are not to be recommended

As Ron says, there's not a great deal of sophistication but a vast amount of experience has gone into the car. It shows in thousands of little things: the overdrive switch on the gearlever knob, for example, ready for instant action: or the reverse lock-out. Apparently when youre dropping from third to second in a hurry you can actually engage reverse by mistake. Oops. There's a heel stop under the accelerator, and a hefty footrest for the passenger. All this sort of attention to detail is what counts in the long run, and it would take a book to cover it all.

The first and immediate impression of JYH is that it's immaculate. Not just tidy, not just clean. No bits hanging off, no different coloured mis matched panels, nothing in fact to indicate that it's had a hard life. This is always a good starting point as far as I'm concerned; it's obviously been exceedingly well looked after, and that gives confidence.
Climb aboard and confidence increases. The driver's seat is a period Corbeau, and the passenger has one of Brown and Gammons' own works type rally chairs. Both are very comfortable, though Ron's legs are longer than mine so even with the seat right forward the pedals were a bit of a stretch away but they're all on the same level, and even more importantly the brake and accelerator have a similar arc of movement for easy heel and toeing. The heel rest under the accelerator helps here too. The transmission tunnel acts as a left foot rest. All the other controls are in standard MGB positions, falling as they used to say readily to hand.

Starting is instant, though idling is a mite lumpy with the race cam. I expected an in or out racing clutch - nothing of the sort. It's light and progressive which is just as well since that cam again makes moving off slightly tricky. I never actually stalled it, but there was perhaps a bit too much clutch slip for long term comfort.

Get going and the first impression is of those straight cut gears in the box wailing loudly, the rorty exhaust adding a basso profundo rumble underneath. This is not a quiet car. Below about 2500rpm the engine doesn't really want to know what life's about either, stumbling and stuttering, but get it over 3000rpm with any sort of throttle and it's like being tied to a rocket. The tacho zaps around to 6000rpm. (Ron used 6500rpm but I stuck to the red line) pulling incredibly strongly can this really only be a 1.8 litre engine? It's smooth and punchy as it all gets out. What's more, it feels and sounds unburstable: there's no teeth gritting cacophany or roughness as if it's going to fly apart at high revs. Even with that race cam it's surprisingly tractable: we reckon you could drive it in London, but it wouldn't be very pleasant in the stop start stuff.

But one of the revelations of the car is the gear change. Cmon: I don't remember the standard item being this slick and quick and light. Ron swears it is standard, but put together properly, a slightly lighter flywheel and those close ratio gears help enormously too. The overdrive works instantly, too, again smoothly and without the jolt you can get in my Healey if you don't dip the clutch: those close ratio gears yet again are partially responsible.

Ron's theories on handling almost go against accepted opinion. He keeps the suspension supple, especially at the rear, for one very good reason. It keeps the rear wheels gripping. It's that simple. Put on really stiff springs and an MGB will be sensational in a flat corner, but will spin instantly if you hit a bump. And it really, really works: JYH is about the most neutral car I've met. It's almost impossible to get the back out, yet there's no dramatic understeer either. The rear springs on JYH are, in fact, slightly stiffer than standard, but only slightly, and that was to cater for the loads tools, spares, clothing etc that had to be carried in the Marathon.

There is another enormous benefit from suppleness: comfort. JYH was brilliant on a rather bumpy B road, the sort of surface that would have had my Healey leaping from crag to crag. Under these conditions the B rode beautifully, absorbing everything yet without any sort of float. There's also a sensation of strength in the whole car no scuttle shake, no worrying rattles, no doors flapping, no looseness at all.

There was some kick back through the steering, however. Not enough to be a problem, but noticeable. Ron put this down to the standard steering arms being used with lowered suspension, which means they work at an odd angle. Talking of steering, that's another thing: on JYH it's crisp and sharp, perfectly weighted and nicely direct. And it's standard the only change is a smaller steering wheel. That makes a helluva difference though.

I climbed out of JYH mightily impressed. I could see now why MGBs had done so well in the Marathon. Don't get me wrong: you've still got to be a pretty ace chauffeur to finish up there in the top ten, but given an MGB like JYH it would be a lot easier. It's on your side. It's the combination of things that does it. There's plenty of power, and with a softer cam there'd be plenty of low down torque for flexibility as well, which is what you really need in the Alps. There's that superbly neutral handling, and the soft suspension for plenty of grip in the rough stuff. There's the ease of driving it because of the lightness of the gearchange and the other controls.

Above all there's the comfort, both from the suspension and the cockpit, allied to a feeling of sheer strength and solidity that means you can bash on for days on end without fatigue. And that has to be worth an extra 50bhp, if only psychologically...

GAMMONS SENSE

We asked Ron Gammons what you can do to an MGB to make it basically a very good road car with the odd occasional sprint or minor rally in mind. Here's what he said:

"Make sure, firstly, that the car is mechanically sound. This may sound trite and obvious, but we've seen cars with ill matched tyres, shock absorbers not doing anything, kingpins worn, not tracking properly, wheels buckled, using a pint of oil every 50 miles the horror stories are legion. So make sure it's to proper specification.

'Next the brakes. There's absolutely no point in making it go faster if it won't stop. Safety comes first. Make sure discs and callipers are in good condition and working properly, and for road use that the rear wheel cylinders are the correct size. If you want to compete seriously, it is possible to fit smaller rear wheel cylinders to prevent lock up under hard braking. I use Mintex 171 pads: some prefer DS11s, but you have to keep them warm and on a long motorway haul in the rain, for example, you might have a problem with your first stop. They're also a bit hard for everyday use. One tweak that has been known is to fit V8 pads, which are bigger with more friction area. It's essential to keep brakes cool too, so if you're going to fit a spoiler make sure there are ventilation holes in it. Again for very serious work you can take the backing plates off but that lets in water and stones...

"Then comes handling. Here it depends on how serious you are again about racing, and how much you're prepared to sacrifice on ride. You can start by stiffening up the suspension slightly, but stiffness alone doesn't equal handling, especially at the rear. On the contrary. If it's set up too stiff at the back a mid corner bump can send you spinning. Keep it soft and supple. Going up in stiffness at the front isn't so much of a problem JYH is set up with 6001b springs and 25 per cent more damping (both on bump and droop) at the front. A 3/4in anti roll bar is a good compromise standard thickness is 9/16in. Make it too stiff, though, and you can suffer from terminal understeer. It will also wear out your tyres.

"When it comes to the steering the standard rack is fine: all you need to do is fit a smaller wheel, 13 or 14in diameter. The smaller the more responsive, but it also makes the steering heavier. As for wheels and tyres, assuming you're going to stick to homologated sizes, then go for wire wheels, since they're easier to remove in an emergency, at the track, or even just for something as simple as pad replacement. Some tyres Michelin MXVs are one make the steering a bit heavier too: Uniroyals and Pirellis can be recommended here.

"Next, axle ratios. For a road car stick to the standard ratio of 3.9:1. This gives about 22mph/1000rpm in overdrive top, which means you'll never be able to pull maximum revs. If you must change go for the most you reckon you'll ever need, say 110mph, which means a 4.3 or 4.55:1 axle. However, this lowers the overall gearing quite a bit, which can be unpleasant if you do a lot of motorway cruising.
"After the rear axle comes the gearbox. Close ratio units are available for both 3 synchro and 4synchro boxes. With these, first is much more useable in a race or rally, and of course the gaps between gears are much smaller, which helps both in performance and gearchange quality. However, a close ratio box and the 3.9 axle isn't recommended: last year JYH was so fitted. First was good for 60mph but hopeless on the Stelvio and other hills it was too high to let the engine pull at very low speeds!

Finally, the engine. Assuming it's basically sound there's no point in doing anything at all if it isn't! - then if you're going to use the car on the road limit any modifications to maintain a good spread of torque throughout the rev range. Sounds reasonable, but you'd be surprised what people try and fit and then wonder why the car's become undriveable in traffic.

"Remember, with an engine, if you gain something somewhere then you lose something somewhere else. More bhp at the top end means a sacrifice of driveability at the other. Initially, then, simply do things to the outside of the engine. Fit an extractor exhaust manifold, for a start. On rubber bumper models you can remove the emission control spec distributor and fit one from a chrome bumper spec car. Then you can move onto some flow work on the head, perhaps with a slight increase in valve size. The next step is to consider the possibility of cam changes, of which there are a range available.

"Then, and only then, is, it worthwhile going to a 45DCOE Weber or 1 3/4in SUs. Bolting them straight on without the other mods isn't going to do a thing except lose you tractability. A big carb gives you more choke area, but the air is moving more slowly, so cylinder filling is worse...

"Finally, of course, you can go the whole hog with flat-topped pistons, full balancing, perhaps a lightened clutch and flywheel (but remember this will make the engine rougher and difficult, yet again, to drive in traffic).

"Brown and Gammons sell various conversions, from stage one to stage four, so you can take your pick, depending on what you want. Even go full race, though this will set you back 2500 (1989 price)... Really it's a case of deciding what you want, and for road use you don't want anything too wild.
Michael Watkins

It is always good to have nuggets like this to read and on hold within the BBS's archives. It tends to benefit the most people, that way, I think. Thanks! :-)
Bob Muenchausen

Great reading.
I've heard it all before but to read it all in one article makes it a pleasure to read.
Onya Mike.
. . . . . henry
H O

This thread was discussed between 28/08/2003 and 29/08/2003

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