Triumph Dolomites

Magazine Subscription

Subscribe to Classic Motoring Magazine and save over 20%

Subscribe NOW

Available at all good newsagents including WHSmith

How to give your Sprint staying power plus we also show how to make an 1850 go as well as the 16 valver!

Forty years ago Triumph’s Dolomite Sprint was dominating the ‘showroom spec’ Group 1 British Saloon Car Championship (which was nothing like the high speed banger racing of today-ed) and yet renowned tuner Ralph Broad of Broadspeed is on record saying it was the worst car he ever had to sort out for racing – and he used to prepare Ford Anglias! Clearly, the car’s success showed that there was enormous scope for improving this Alfa/BMW rival of the 1970s.

And there still is, not simply for the Sprint but also the 1850 Dolomite and even the Spitfire-powered 1500TC as, apart from the engine, the same tuning rules broadly apply.

BEFORE YOU START

With almost 40 years’ experience, Brian Kitley is one of our leading experts in Dolomite Sprints and says before any tuning and modifying is carried out you need to bear in mind the car’s increasing rarity and so not spoil its originality making needless alternations. Any tuning Kitley carries out is in accordance of the car’s 1970’s homologation papers so cars can comply for historic racing and rallying.

So while there’s a fair smattering of tuning parts and aftermarket kits around, perhaps the smart money goes on using genuine BLST and Stanpart goodies which, while not available off the shelf, are around if you look hard enough. Here’s why: Brian Kitley owns one of the works rally cars which is valued at around £38,000 and says he’d gladly pay over ten grand for a really good original road car because their values will rise…

Rust is the main worry as always so check everywhere – and we mean everywhere! Wings are virtually non existent and sills are now going that way. The engine’s weak points concern the water works and the water pump in particular. But a well serviced Dolomite needn’t be an old boiler; Kitley advises advancing the ignition slightly and making sure the engine breathes better to reduce the risk. We’d further advise using Evans’ Waterless Coolant as another safeguard.

HOTTING ONE UP

The Sprint used a hybrid 2-litre 16 valve tune of the conventional Dolomite engine which in turn was a development of the earlier unit it co-designed for Saab.

However, don’t think that the Swedish engine can be made to fit in the Triumph because later Swedish units shared virtually nothing with the Canley unit.

However, we have seen Stag (the unit is effectively half a Dolly engine) and even Rover V8-powered Sprints which aren’t too difficult swaps and certainly give this saloon a unique character and yet also keep a thread of originality.

Back to the Dolomite engines… If you have a good 1850 model, avoid the obvious temptation of slotting in Sprint unit because with some off-the-shelf modifications to the breathing (air filters and exhaust) you are on your way to an average Sprint unit, while adding the larger Sprint carbs and a better camshaft (try Robsport International, Brian Kitley or TriumphTune) and you’ve practically Sprint power without any of the hang ups and more torque. You can further improve the latter by using a TR7 2-litre block, or having yours bored out to 1998cc.

Sadly, the problem with the 1850 unit is its Stag-like single timing chain design which can be a weak point and no you can’t simply fit a Sprint head to an 1850 (or indeed a TR7 unit) due to this plus the pistons need to be changed as well.

Now on to the Sprint unit, which like other Triumph units seems to vary in terms of power outputs meaning you can have a good ’un depending upon your luck.

Originally, the unit was to be rated at 135bhp but it was found that it couldn’t consistently be obtained during production so it was de-rated to 127bhp, although well set up test bed engines saw as much as 150bhp! During its golden Group 1 days, Broadspeed saw a healthy 165bhp once ‘Blueprinted’ to factory specs and almost 180bhp if the later ‘emissions’ camshaft and 2inch SU or Weber carbs were added; full race and rally engines are quoted at 235bhp and 190bhp respectively. In complete contrast, a typical Sprint engine that’s seen better days is probably kicking out less than 100bhp!

So it stands to reason that the best initial steps are a thorough going over paying attention to a top end and carbs overhaul – add electronic ignition if not already fitted. Along with session on a rolling road to set it up you should see your 127bhp or a bit more if you also include better air filters and exhaust system.

After this you need to look at different carbs. Twin Weber DCOEs are ultimate and used in competition but twin 2inch SUs (from a Jag XK engine) cost much much less and do almost as good a job for most uses although can rattle against the bonnet’s underside. According to leading expert Kitley (http://www.briankitleytriumphs.co. uk), the standard 16-valve head is a pretty good design already and hard to improve upon with larger valves although it has been done. Easier tasks are matching the manifolds to the head, conventional gas-flowing with a compression ratio just under 11:1 and ensuring that the valve seats are cut for optimum efficiency.

A varied camshaft range is available from Mssrs Kitley, Piper, TriumphTune, Jigsaw, etc depending on your personal requirements; Kitley uses the Triumph STR 0139 model which can be fed well by SUs or Webers, the latter which he says aren’t really necessary except for competition; if you opt for them, then the 48DCOEs make for a nicer engine, he adds.

The Sprint engine is not great revver although will take around 7500rpm easily but above this you need a block brace to strengthen it along with better main bearing caps. Kitley recommends standard Mahle pistons but as these are now unobtainable he relies on the expensive Cosworth alternatives. The con rods are similarly robust but it’s always worthwhile having the complete assembly balanced.

Even if you envisage just mild mods, you’d be mad not to invest in a superior head gasket available from all leading specialists along with new head studs, either standard (such as Moss) or modified from SprintParts; owners recommend torquing down the head in the conventional sequence rather than Triumph’s quirky method, but get advice on this along with recommended torque wrench settings; Kitley tightens them down to 58lbs.

HANDLING THE POWER

The Sprint was regularly said to have been a great engine looking for a chassis and while there’s a bit of truth in this, the Dolomite can be improved. Start by uprated dampers and slightly lower springs from Rimmer Bros and other experts. Together with polybushing (chiefly engine subframe, anti roll bars, suspension and diff mounts) it may be all you require but you can go much further with modern coil-over kits for track work. To improve steering response, fitting Ford Sierra top mounts to the front struts works well. More extreme mods known include bespoke anti roll bars front and rear originating from Ford Sierras, a Panhard rod to tie the axle down better (made from a Fiesta bar) and adjustable tie bars but these mods are more suited for track use.

Brakes have always been marginal on Dolomites and the Sprints especially. EBC pads are the obvious starting point before going to larger brakes either aftermarket (Willwood) or Capri 2.8i (if you can find them). Sticking to originality, Kitley has Group 1 vented discs made but they are mega dear at over £500! Stag brakes are slightly larger which may help.

For road use the rear drums will suffice and if you want more modern tyres then 15inch MGF rims fit. Racer Rob MacGregor uses modified Ford stub axles which mate to the Dolomite vertical link, allowing Ford bearings, front hubs, brake callipers etc to be fitted. As a result you will have much more choice over what brakes and wheels to use but you will have to modify the rears to match Ford’s spec.

Let’s talk transmissions. Many Dolomites featured a manual gearbox with overdrive, as did the 1850 and even the 1500TC which effectively allowed six speeds. The obvious upgrade is to fit a TR7 five-speed unit (or the ubiquitous Ford Type9) but Kitley says don’t dismiss the o/d, particularly if you want to go rallying as it works brilliantly when allied to the special wide ratios gear set Triumph once made. In contrast, a close ratio set for racing was also homologated and while Brian doesn’t hold any, he does posses all the info and factory drawing so can give you their specs for manufacturing but this won’t come cheap. Incidentally, Dolomites used an unusually tall first gear which could take the car up to 50mph. If this isn’t preferred – say for towing – then very early Triumph 2000 gearboxes posses a lower ratio.