Triumph TR7

Even staunch TR7 critics have to concede that they drive much better than they look.

It’s the last of the TRs and without any balls! We’ll that’s the common perception of the TR7 – but there again any sportster sacrificing a brawny straight six (with fuel injection) for a tepid four pot was always going to be on a hiding to nothing. A TR6 it most certainly isn’t… but if you view the TR7 as a modern MGB then one makes sense to own and tweak.

So let’s have a good look at this much maligned GT that has a lot going for it, not least a good chassis and great value. And what’s more we’re not going to mention fitting a V8 either…

Get One Now

There’s really only two TR7 models, the oddly styled fixedhead and the far more elegant roadster. Changes to the range over its short five year run were few; the option of the SD1 Rover gearbox being the most prominent.

The TR7 was powered by a unique engine, using the Dolomite Sprint’s 2-litre bottom end, topped by the normal 1850cc eight valve cylinder head, albeit still good for 105bhp (US cars were only rated 90bhp) and some 60 versions were fitted with full fat 16-valve Sprint engines.

A formidable rally car in its day, the TR7 can make a good fast roadie that’s ideal for mild motorsport. Prices still start from not much more than £1500 for average examples although truly specimen ones have been known to nudge the five figure barrier.

There are several well known variations, and special editions, such as the Premium, black with gold decals; the aforementioned TR7 Sprint, with a Dolomite 16-valve Sprint engine; the Spider, which is black with a hint of red in it, (Maraschino), and red stripes; and the Coca Cola cars, which were given away as competition prizes.

Terminal rust everywhere, but particularly at the inner wings, bulkheads and sills, is the biggest worry along with the engines (which is half a Stag’s V8 remember) developing head gasket blowing and overheating tendencies.

It’s not necessary to go down the V8 route if you want to get more power from your TR7. In fact, some would say that the weight penalties of the V8 unit, compared to the standard unit, with increased weight which is also placed further forward in the engine bay, can make converted V8 cars handle worse than standard cars.

Hotting One Up

We spoke to John Clancy of the TR Driver’s Club, who has one of the fastest TR7s that’s still running the original two-litre engine. If you’re after a fast TR7, his example is a good one to follow and specialist such as Robsport International (http://www.robsport.co.uk) will help you to get hold of the parts you need.

TR7s were originally quoted as producing 105bhp, but at best this was the power at the flywheel, with rolling-road power readings being closer to 85-91bhp. With fairly simple tuning, John managed to get his TR7 up to 120bhp on the rolling road, but says he has since toned this down a bit, for smoother running.

Starting with the top of the engine, john has fitted a ‘Sprint’ profile high-lift camshaft (nothing to do with the Dolomite Sprint, but just the name for this type of performance camshaft), which will cost around £200 – you can fit lessextreme performance cams if you want. John has also replaced the car’s standard twin SU Carbs with twin-choke Weber 40 DCOEs; the bigger 45s are better but maybe not worth the added cost.

It’s also worth mentioning that the factory originally used penny-pinching head gaskets, which are partly responsible for the car’s poor reliability images. A rubberized-type of gasket was originally developed for this engine, but Triumph’s accountants wouldn’t have it. Specialists such as Robsport can now supply Payen gaskets which allow for a bit of flexibility. So, if you’re rebuilding your engine, one of these is well worth fitting. You should also always use a rust-inhibitor coolant in your TR7, to avoid corrosion and the resultant clogging of the waterways.

John has also fitted an extractor sports manifold to his car, as well as through-flow exhaust, plus K&N air filters and these really help pull out the power. If you’re keeping your twin SU carbs, you can also fit new needles to suit. With all these modifications – plus a good electronic ignition – you should be getting closer to 110bhp on a rolling road which in real world terms is practically Dolomite Sprint power and pace and with better torque.

John also says that early cars equipped with the original four-speed gearboxes (which are now becoming more collectable) actually feel a bit faster than later five-speeders, due to the fact that the ratios were stacked closer together. However, if you’re doing lots of motorway driving, the five-speed box is probably better.