Sunbeam Alpine

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Don’t be fooled by its looks and character, Sunbeam’s Alpine can eat a Tiger if tuned right. We show how plus look at all saloon derivatives up to the late ’70s

Compared to its main rivals, such as the MGB and the TR4, Sunbeam’s Alpine has widely been regarded as the softer option. And while its true that this Rootes roadster panders to those who want a comfortable life, it can be given such an attitude that it would tame a Tiger let alone make mincemeat of an MGB!

Our tuning tips and advice comes from Alpine aficionado Chris Draycott (01332 850856, .(JavaScript must be enabled to view this email address)), who is well known for not only keeping the Alpine flag flying but is also an expert on Rootes models in general, which is why this feature also covers the Minx, Sceptre, Commer Cob, Husky and the later post 1966 Arrow line up. So if you want to scale new heights with your Alpine (or the saloons) – read on!

BEFORE YOU START

Rust is the biggest worry. Alpines can sag in the middle when jacked up signifying that the structure is shot. Check the door fit, if a gap of more than 1/8th of an inch opens up then there’s trouble. Chief rot areas are the inner sills, floors and around the jacking points/chassis frame, inner wings and particularly the front chassis legs. Other suspect areas are around the box sections, suspension pick up points and steering box mounting.

Inspect the boards and rock the seats – if they move then chances are the body is dissolving. Behind the seats lies the structure where the axle hangers resides scrutinise carefully. The saloons rot in all the usual places.

All engines can become clattery, which is usually due to the cam followers. Smoking units are equally common and are a result of dodgy valve guides. If they’re serviced correctly then engines will go on and on – but it’s best to use a full-bodied 10W/60 these days.

Fully synchromesh gearboxes didn’t arrive until ’65 but a newer ’box may have been fitted over the years. Worn examples can whine or jump out of gear.

HOTTING ONE UP

The Alpine (and Minx saloons) used three engine sizes, 1494cc, 1592cc and 1725cc, the latter which was also used in milder single carb form in the Hunter saloon and Alpine fastback of the 1970s. The ‘Arrows’ Minx 1500 engine was a smaller version of the 1725 unit and different to the earlier 1.5.

Before we start it needs to be pointed out that it was common for Rootes to fit alloy cylinder heads to its upmarket saloons like the Hunter, albeit in single carb form. If you have an ‘iron’ headed engine you can’t simply substitute it with an alloy one as the manifolds are different. The iron head, while not quite as efficient, can be modified in the conventional manner although Rootes guru Chris Draycott says he’s done very few.

According to Draycott the ‘1600’ is the weakest engine and as they look visually the same (apart from the location of the dipstick on the 1725 unit) it makes sense to fit the largest unit and gain an instant power and torque hike cheaply. Chris has taken several blocks out to 2-litres and even races one adding it makes a very nice road engine if left pretty much in plain Alpine tune. However, this bore and stroke exercise doesn’t come cheap at some £3500.

On the face of it the best bangs for your bucks must surely come from slotting in the hallowed Holbay tune engine, as found in the Rapier H120 and Hunter GLS? Not so according to Draycott who says the lump is a “waste of time” because it was poorly conceived. Originally 120bhp was extracted (hence the name) by this famous Suffolk engine tuner – however in such a high tune state it was badly behaved on the road and so power had to be clipped back to just 95bhp – something a normal Alpine engine can easily achieve and with less fuss.

Chris says he has seen 200bhp+ on his racing engines and says 140bhp is attainable for reliable road use with a 1725cc engine. Don’t assume that the Alpine unit is the same as those fitted to the Rapier or Hillman Hunter GT because the sports car’s camshaft was unique to that model. Not many know that, as Michael Caine might say, and this is borne out by Draycott who claims 98 per cent of today’s engines are not running on the ‘298’ camshaft anymore! Uprated cams are available from the man or you could seek out a Kent Cams alternative.

Apart from electronic ignition, Chris says the best single modification – so long as the 298 or similar cam is installed – is a high performance, unleaded, head of which he charges £350 (or £750 fitted and set up). On twin Stromberg carburettors you’re looking at comfortably over 100bhp but if you want to see close on 140bhp you’re going to need twin Weber DCOEs as found on the Holbay engine.

Ah yes, Alpine carbs! Rootes really chopped and changed them; initially the Alpine ran on twin Zeniths before a year’s flit with a single Solex instrument before going to twin CD Strombergs. Draycott’s experience suggests that the Zeniths work fine but they wear and are extremely pricey to overhaul. The Solex unit isn’t bad but the best news is that the manifold accepts a Weber 28/36 DCD unit with no mods and anyone who knows these fuel-flowing devices will vouch for their excellence and wide scope for adapting to engine tunes by changing their choke and jet sizes.

Extracting all these spent gasses is best done by a sports exhaust and the Alpine’s stock unit is a decent design. Alas, the superior tubular Holbay one can’t fit due to engine location but it’s an easy fit on the ‘Arrows’ saloons. Talking of which… The easiest route to perk up a normal saloon is to fit an engine from a Sunbeam Rapier or Humber Sceptre which for many may prove more than adequate. The Holbay engine is quite a bit dearer due to those twin Weber DCOEs (which will probably need an expensive overhaul anyway by now) and to be quite frank, is a bit too peaky for casual classic touring driving and quite noisy.

Apart from normal engine lightening and balancing work, if you are rebuilding the engine, a skimmed flywheel aids throttle response but you can’t go too mad here. Tempted by turning your Alpine into a Tiger? Given what they sell for it’s perfectly understandable but the conversion is similar to making an MGC from a B – it’s far too complex and not worth the effort, especially since the stock Mk1 Tiger only kicked out 165bhp. In contrast, a racing 1600 Alpine, in period can yield almost 150bhp and good enough to keep up with its V8 brother. Just a final word on the 1500 engine used in the ‘Arrows’ Minx; being a shorter stroke 1725 unit, it’s quite a ‘screamer’ when tuned says Draycott and popular for competition as it means the car can fall into a lower class of competition.

HANDLING THE POWER

Let’s talk transmissions first. In common with the MGB, overdrive was a highly useful option on Alpines (and Minx/Hunters) and well worth preserving with as fitting the celebrated Type 9 Ford Sierra ’box is very difficult due to the positioning of the gear lever, which on Alpines means that the chassis ‘cruciform’ requires cutting and shutting and as a result can weaken the shell. Happily four-speed Escort ’boxes can be used – or you can keep it original and have an uprated overdrive fitted instead. Slotting in a 3.89 differential makes a nicer car on the road adds Draycott.

The Alpine is a bit of a softie and more a GT in standard form but can be made to handle well says Chris who says his track car has “run rings around Tigers” due to its greater agility. Start with uprated dampers and springs (the latter preferably 1.5inches lower) before adding one of his 7/8in front anti roll bars – but don’t try to fit a rear one.

On the Alpine (and pre-Arrow Minxes) there’s a little trick worth knowing and employing to improve the car’s steering geometry. It concerns the shims fitted to the top front wishbones because by simply transposing them you add a touch of negative camber. Chris Draycott says there’s a bit more to it than that and additional shims may be needed to suit individual cars plus he says you’ll also need a caster correction shim which he can also supply. Polybushing is worthwhile and with the rear suspension sorted there’s no need for anti-tramp bars.

The later Arrow-derived cars (Minx, Hunter, Rapier) ditched the wishbone set up in favour of a Ford-style McPherson strut format. The usual lowering, stiffening and polybushing tactics apply as the rear leaf rear springs ideally need some help to hold the axle straight. The H120 and GLS featured stronger stub axles but there’s no advantage trying to install them on an Alpine adds Draycott.

At the rear, all apart from S1 and S2 Alpines use telescopic dampers and the good news here is that even when complying with FIA homologation rules, early Alpines can be suitably uprated without falling foul of the regs – the bad news is the work involved and the cost; Draycott typically charges £500 to do this.

Brakes are up to mild mods if in good order and fitted with the likes of EBC Greenstuff pads. More involved mods can include aftermarket uprated callipers although you can use Ford Escort items as they are identical, which in turn means you can even fit 2.8i Capri ones. You’ll have to up the tyre size to 14inch rims if you go this far – many don’t want to sully the originality – but go for six inch rims shod on 185/60 radials and you’ll have all the grip you are likely to need.

The old fashioned steering box isn’t bad if in good order (having an overhaul may transform yours) but you can’t fit rack and pinion as used on the Tiger although an EZ electric power steering can be adapted if the tiller is deemed too heavy.