There is a lot of talk of unreliability surrounding the Al Melling-designed Speed Six engine. Much of this is directed at the earlier Mk1 engines, but most Tuscans will now have been improved or had their engines rebuilt to a much higher standard to cure these problems. When buying a Tuscan, look for paperwork to prove an engine rebuild or work by a specialists such as TVR Power, Str8six or Racing Green among others.
The first engine in the Tuscan was a 3,996cc all-alloy in-line six-cylinder motor with four valves per cylinder to create 360hp. Dry sump lubrication was a result of the engine's development in endurance racing. This was then joined by a 3,605cc version with 350hp, while the 4.0-litre S dished up 390hp. For the Mk2, capacities remained the same, but power for the 4.0-litre in standard trim dropped to 350hp and the S stayed at 400hp. A Borg Warner T5 five-speed manual gearbox is used in all Tuscans, but it is working close to its performance limits.
Check the gearbox changes into fifth gear smoothly. If it doesn't, it's not a disaster, but will most likely mean a new circlip that holds fifth gear in place. A cheap part to replace, but removing and stripping the 'box will be expensive. A spongy clutch pedal feel is likely to be the seals on the clutch slave cylinder, which is a much cheaper fix at around £12 plus fitting. Clutches will last between 20,000 and 30,000 miles depending on the type of abuse they are subjected to. A new AP twin-plate clutch will cost around £600 plus fitting from a specialist.
Warming up the Speed Six engine properly before using its full potential is very important. It can take up to 20 minutes for the engine to be completely warmed through, so beware any seller who revs the engine hard while it's still cold. Conversely, engine bay temperatures get very hot under the Tuscan's bonnet and this takes its toll on alternators, starter motors, the Anderson plug used for jump starting the car and even the powder coating on the chassis. Faulty starter motors should be easy to spot, while a worn alternator is simple to replace. The Anderson plug is tucked under the passenger's sill, but heat from the engine causes the plastic to break up and exposes the wires to the chassis' metal. A new Anderson plug is not expensive to fit, but make sure the correct heat shielding is present or replaced at the same time.
Countering the high engine bay temperatures is best solved by fitting improved all-aluminium radiators. It's also a good sign if the car has been fitted with upgraded silicone hoses in place of the original rubber items.
When the engine is hot, poor idling can be due to bad earthing connections, a faulty ECU or, worse still, worn finger followers. The first two problems are straightforward to fix, but worn finger followers, which operate the valves, are a much bigger problem. Look for oily deposits on the exhaust tips as a sign of worn followers. Mk1 Tuscans suffer from this much more and the permanent fix is to replace them with new steel items. A lot of owners bite the bullet at this point and opt for a rebuilt engine, which will cost you £5,400 from TVR Power and comes with a three-year, unlimited mileage warranty such is their confidence in the strength of this engine.
TVR Power and other specialists also offer uprated engines, the most common being to 4.3-litres, though you can take the Speed Six engine to 4.5-litres. Depending on the conversion work, power can increase to 450hp, with prices around the £8,000 mark.
The Tuscan's exhaust system is prone to damage from speed bumps, so check it's in good condition. Many owners choose rear exhaust pipes from the Carbon Can Company that give full vent to the Speed Six's engine note and are a worthwhile addition to have.
The final problem to check for is a sticking throttle cable. It's a common fault with the Tuscan and some owners carry a spare cable for this reason. Another popular upgrade is to fit roller bearings to the throttle bodies to replace the wear-prone bushes fitted from new. Budget on £600 for this modification.
Owner's view:
"I'd always recommend buying on mechanical condition rather than how shiny the bodywork is. The engines on these things can be one of the most expensive things to fix (my car had receipts for over £10K for an engine rebuild). The TVR reliability stigma isn't there by coincidence and some of the early engines had internals made of chocolate. There are two very well renowned engine specialists now, and I have used both for servicing - Str8six and TVR Power. I would not have any qualms about either working on my car."
Nev Lorimer