Morris Minor

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One classic codename, one shared design, so the way to tune them both stays the same and with some spectacular results – as we reveal

Modded Morris Minors are becoming more common sights, because many owners are tuners and improvers without even knowing it! Accepted modifications are increasingly filtering through to seemingly standard cars, while the thriving Young Members section of the MMOC will keep the flag flying for generations to come.

Thanks to the Minor’s mechanical make up you can go mild or wild easily and yet not dilute the car’s innate charm, character and reliability. In this Road & Track special we’ve teamed the Morris up with its spin off, the Riley 1.5 and the Wolseley 1500. If anything, as this pair already boast the larger B-Series engine, they can be turned and improved into even better classics.

Before you start

Mechanically, these cars are as simple to repair as they are to rev up – it’s rust that makes them all a worry. Ensure that the main structure, including bulkheads, crossmembers, floors and rear suspension location points are sound. Rear chassis extensions, suspension hangers and front chassis legs go, as does front crossmember.

The rest is mostly cosmetic and easily repaired or replaced with new panels from a variety of places, although panels are much harder to source for the Riley and Wolseley cars.

The oily bits are super simple; chief concerns are the front suspension trunnions and king pins. A new king pin leg costs some £75 but will also improve the handling. The brake master cylinder lives inside the chassis rail and is quite easily overlooked as a result.

All engines are robust, signs of wear including rumbling crankshafts, undue tappet noise and the usual oil burning, crankcase fuming and low oil pressure. BMC engines also suffered from valve seat recession more than most and are also known leakers from a variety of areas such as the tappet chest. Leaking at the crankshaft oil seal is also a common problem on the A-Series. To get round this problem http://www.jlhmorrisminors.co.uk has devised a Maestro crank and breather conversion for any 1275cc unit.

It’s wise and simple to drop the sump and renew the crankshaft shells and bearings every 50,000 miles and certainly before any heavy tuning is carried out.

Hotting one up

Let’s start with the Minor first. Today’s most common performance upgrade is also the one that’s been around the longest and that’s slotting in a 1275cc A-Series unit, from the MG Midget. These are available reconditioned; MGOC offers a standard but lead-free unit for just under £1600 or a fully modded 1275cc Stage 2 alternative for £2259 which is not a bad deal.

The best bit is that most classic insurers won’t load your premium as a result. You don’t have to run on the Midget’s twin carb set up and even normal Minor carbs can be retained (although a larger re-calibrated 1.5in carb is best), along with the exhaust manifold if you wish to keep an original Minor look. However, you won’t get the best out of the unit; ditto using a 1275cc block topped with a 1098cc ‘top end’.

For many, just the added bhp and more importantly, torque of a normal 1275 more than suffices. However, there’s 100bhp potential with this excellent unit which can be bored out to 1380cc and even a staggering 1425cc by way of ‘offset crankshaft grinding’ plus the unit can be supercharged. If you have a sound 1098cc engine, there’s no need to ditch it as it’s a sweeter unit and can still churn out an honest 70-80bhp plus can be bored out to 1.2-litres safely.

If you stick with a 1098cc it’s preferable that it’s the unit that featured larger main bearings and even then should regard 80bhp about the max you’ll want to eke out.

Up top, even on the standard 1098cc you can improve performance by fitting a Stage 1 (or Midget) head, although the first step is breathing upgrades to the air and exhaust systems such as a K&N filter, Midget exhaust manifold, etc. Concerning camshafts, there’s huge choice but the Midget one is as good as any for many as it provides useful poke but doesn’t make the engine too racy and hard work in traffic. But for power, best camshafts are profiles similar to BMC’s Formula Junior 544 or 567 type with the 595, 648 and 731 profiles more suited to competition; MGOC sells modern fast road alternative cams and kits at £375.

A new trick mod for the A-Series is Minisport’s roller tip rocker assembly. In a nutshell, it gives the same effect as a racier camshaft but without the need to strip the engine and costs less than a camshaft at £182, although it’s sensible to fit new valve springs to prevent valve bounce. Unless you want the ultimate of a single DCOE Weber carb, twin 1.5in SU carbs can fuel all the added power you’ve unearthed.

The B-Series unit installed in the Wolseley and Riley is the original 1489cc unit found in the Austin A55 with Rileys running MG Magnette tune. Taking both to full MGA tune with the appropriate cylinder head and camshaft is the obvious first step but this engine can give much more, particularly if you also take the opportunity to go larger to 1622 or even 1798cc and take it to initial MGB spec (95bhp). The MGB engine can be installed, but the early ‘three-bearing’ unit is a much more straightforward swap than the slightly larger, later five bearing type.

How far do you want to go? B-Series can be further stretched to up to 2.1-litres although the 1950cc is generally regarded as the best all rounder where in a fast road guise can deliver some 110-130bhp and with lots of torque and reliability.

MGOC sells standard MGA and MGB engines from £1530 and £1980 for a 2-litre, or £2190 if balanced; fully blown 2.0+ engine costs almost £3750. Moss’s ‘Stage 2’ alternatives range from £2587- £3478. It’s well worthwhile having the crank and rods balanced plus lighten the heavy flywheel to improve the throttle response.

A claimed 40 per cent hike by supercharging costs £3000 and the engine must be in good order. Webers only gain advantage at higher revs. Moss Europe offers its new Mikuni ‘bike’ carb kit, an alternative to DCOE Webers at £985.

Even if you are not upgrading the engine performance it’s still worth fitting a electronic ignition system. For instance, http://www.aseriesspares.co.uk sells a Standard Road Electronic Distributor, together with a Unipart GCL211 High Output Coil for just under £100. Really highly tuned Minors may demand a Cooper S distributor to get the timing right and avoid piston burn out.

Big time performance comes also in the shape of another engine and many have been shoehorned into Minors over the decades, including meaty V8s. Now folks look to the Rover K-Series, or the Ford Zetec engines as easier more accessible and cheaper alternatives. Specialists JLH Minors has been marketing a K-Series upgrade for Minors for a decade. The kit includes parts such as a new bell housing to attach the engine to the gearbox. There’s parts to upgrade the cooling system, too.

Fitting a B-Series into a Minor sounds simple enough and yet is one of the most difficult swaps of them all as the larger engine sticks proud of the nose and, crucially, over the axle line, thus altering weight distribution. To compensate, either the bulkhead has to be drastically modified or the front grille extended. Many, many years ago, tuners made special ‘split radiators’ to enable the crank pulley of B-Series to fit between the two rads so the ‘snout’ can mostly remain standard but we doubt if any are still around.

Handling the power

Fitting the evergreen Ford gearbox is a popular conversion yet it’s not automatically worthwhile. According to Minor experts, JLH Minors, it’s only worth doing if the engine is suitably uprated so it can successfully ‘pull’ the higher ratio easily. Minors powered by a standard 1098cc engine will be too sluggish to take full advantage of a fifth gear, JLH contends, adding the added cog is nigh on useless as a result on anything other than a motorway or flat road.

One solution is to fit a 3.9 or 3.7 differential (from a Midget or Marina, the latter which sports a tougher rear axle). Ideally, you need in excess of 60bhp, either by tuning or opting for a more powerful lusty engine such as the 1275. The brawnier 1.5-Series has no such problems.

You can buy a modified Ford Sierra five speed gearbox for your Minor from www. morrisminor.org.uk at a cost of £1425 with its nut and bolt fitting kit. The MGOC advertises Type 9 boxes for £795 but a complete (Midget) conversion at £2200 so it pays to shop around.

Don’t try adapting an overdrive MGB gearbox in either a Wolseley or Riley as it won’t fit without a lot of fettling to the transmission tunnel and propshaft.

Charles Ware feels a five-speed works well even with a standard tune 1098cc engine and provides a conversion kit (see news pages for some developments-ed) at £2112. However, son Zak Ware stresses that even fitting a standard tune 1275 engine (which the company sells for around £2500 fitted), it’s essential that uprated driveshafts are part of the conversion.

In its day the Morris Minor was one of the nicest handlers on the road and with the added power of the B-Series engine, the Riley became a quite formidable racer, humbling Mk1 and Mk2 Jags in its day.

Front discs are worthwhile but not always a must. Better linings (Ferodo VG95 or Mintex AM4/AM8 were recommended in their day) along with a servo may suffice. The Riley and Wolseley boasted bigger MGA-type drums and were a popular fit on Minors although their rarity, plus advent of disc brake kits, mean few now go this route.

Disc brake conversions utilising Morris Marina or Ford Sierra parts (opinions differ on what’s best) are available costing around £650 depending upon what you choose. A servo is optional and, in fact, some advise owners to try their car out first with just discs fitted while others claim a good drum system with a servo is ample. Some further advise fitting a servo to the front only so seek advice on this first before shelling out on something you may not need! Charles Ware’s servo kit fitted costs under £500 with disc brakes at £820, for instance.

With the suspension it’s a case of how far do you want to go? A relatively cheap tweak is to fit telescopic shock absorbers, in place of the lever-arm originals. You can have a new front suspension handling kit fitted from around £250, which includes telescopic shock absorbers, from www. morrisminor.org.uk. A front anti-roll bar from the same company costs £169. If you want, you can even the torsion bar, using a new crossmember and wide-bottom A-arms, with http://www.jlhmorrisminorsselling a complete new suspension kit for £750. Charles Ware has a Classic Handling Kit which includes an anti roll bar for £163, under £250 fitted.

A Marina rear axle can be fitted (which also supplies better brakes), telescopic rear dampers, MGB rear springs, anti tramp bars… Zak Ware suggests his £385 kit, welding rear turrets to put the telescopic damper at a better angle. To lower, the simplest method is to realign the front torsion bars and fit lowering blocks to the rear springs but this can promote axle tramp and you may need anti-tramp bars to cope.