Triumph GT6
Nigel works through a few more teething troubles
Recent workshop time has focused squarely on completing a short snagging list on the GT6, left over following its recent 2.5-litre engine upgrade. While concentrating on getting the new engine in and running, various lesser jobs had inevitably been pushed into the background.
First task was the wheels and tyres. The eight year-old Pirellis on the car still had plenty of tread remaining, though I’ve never been entirely happy with their wet grip, and age only makes this worse as the rubber hardens. Once or twice I’ve felt the back twitch disconcertingly at modest speeds through wet corners. With the extra power and torque of the new engine, new tyres were a must. First though, I wanted to smarten up the alloy wheels.
They’re Starmags, a Seventies period accessory that’s rare nowadays; they suit the car well, too – at least in my opinion! However, the uncoated alloy faces need regular polishing and the painted inner parts of the rims had started to flake and peel. I began this mini-refurb by sanding and wire bushing off the old loose paint. Once all four wheels were back to a sound surface, the insides of the rims and the recesses between the spokes were hand painted with satin black paint. The makeover was finished by putting the shine back on the wheels’ bare alloy faces, using chrome polish on a plastic pan scourer.
Next job was to choose and fit four new tyres. Local specialist Tanvic Tyres took me through a range of options. I’m beginning to question the wisdom of fitting premium tyres to low mileage classics, when clearly the tyres will not wear out before age dictates replacement. I decided on mid-range Davanti rubber, which has a good wet grip rating and wouldn’t break the bank. Now I’ve put a few miles on the new tyres, they feel reassuringly grippy and the ride is better, too.
While removing the wheels, a potential horror story came to light. The front brake calipers on the GT6 connect to their respective flexible hoses via short metal link pipes, which run very close to the wheel rims. One of these brake pipes had rubbed against the rim and was starting to wear, raising the possibility of total brake failure. I’ve recently invested in a kit of tools, fittings and a reel of Kunifer tube from Vintage Warehouse 65, who specialise in classic brake fittings, so it was easy to make up a new link pipe. It’s now
carefully routed away from the wheel rim and I finished by bleeding the brakes. This episode felt too close for comfort and emphasised the need to keep a close eye on safety critical components. No doubt the problem would have shown up at the next MOT test, assuming disaster didn’t strike first.
Next up were a couple of oily jobs on the new engine. Since it first fired up, there had been a stubborn leak from the timing cover oil seal, just behind the front crank pulley. I’ve never had a problem with these seals before, but despite three changes of seal, checks on its alignment and fitting genuine Payen replacements, the leak persisted. I even replaced the steel sleeve on the crankshaft nose, on which the seal runs. Nothing would stop the flow and, in desperation, I called Chris Witor. It turns out he’s seen quite a few Triumph engines with apparently incurable leaks from this seal. His answer is a step back in time, as he sells a leather-lipped oil seal that he finds usually solves the problem. When his leather seal arrived through the post, I gave it an overnight soak in oil then fitted it the next day. I’m mightily relieved that since then, the GT6’S new engine has remained oil tight.
Cool runnings
The last job was to refit an oil cooler. The original 1998cc engine had this oil cooler, though it’s questionable if it was really necessary. However, the new larger engine was showing signs of getting a bit too hot, as after a few miles cruising at 70mph, the oil pressure tended to drop slightly. Oil pressure stayed within specification, the engine is healthy, but it seems its increased capacity may have put some extra load on cooling and lubricant.
I cleaned the cooler matrix inside and out then bolted it back in place, low down between the chassis rails. It’s as if Triumph had intended a cooler to sit there, since the space was just big enough, was in the air flow beneath the car, and was protected from damage by the anti-roll bar in front. The oil filter adaptor was swapped for one with connections to the cooler and I fitted a new set of hoses, all plumbed via a thermostat so the oil can warm up quickly. After priming the oil system, I fired up. Following a couple of tweaks to the hose connections it was all oil tight. Time will tell if the oil pressure now remains higher when the heat is on.
While no classic car is ever truly finished, I feel that the only significant step left on the GT6 is a rolling road session, to get carbs and ignition advance perfectly set. Given a few more miles, it will be ready.
‘A brake pipe had rubbed against the wheel rim and started to wear’