TRIUMPH 2500TC
RUN BY Greg Macleman OWNED SINCE June 2017 PREVIOUS REPORT May
Putting the key into your car’s ignition following an engine rebuild is always nerve-wracking – doubly so when the entire C&SC team is crowded around the open bonnet in anticipation. All I could think about was the camshaft timing and whether or not we’d set everything up correctly. And the same look of concern was etched on Port’s face as he leant over the engine bay, one hand on the throttle linkage, the other on the distributor.
On his mark I closed my eyes and turned the key – nearly jumping out of my skin as the engine burst angrily into life. The noise was deafening in the underground car park, and so much more menacing than I was expecting. Within seconds the saloon had filled the space with fumes, white smoke and unburnt fuel, causing complaints from the upper floors of the office, and the facilities manager to rush through the smog to isolate the fire alarm. Worried we might prompt a building-wide evacuation, I quickly switched it off… but not before realising we had created a monster.
My initial plan had been to repair the burnt valve and get the car back on the road for summer, but here we are three months and many thousands of pounds later. For a start there’s the camshaft, which we took out and sent to Piper Cams to be re-profiled to ‘yellow’ specification – a grind that majors on usable torque and came highly recommended by pal Matt George and Jason Wright at TRGB. We also fitted a vernier timing gear, replaced the duplex timing chain and added all-new followers before checking the end-float and re-installing the fuel pump and distributor drive.
I went a bit overboard with the cylinder head, too: it snowballed into a full fast-road top-end rebuild by engine wizard Peter Burgess, who’s been in the business for years and has built many a race-winning ‘six’. It turns out that YFH 99M is equipped with the coveted ‘219016’ cylinder head fitted to 2500TCS and 2500Ss – great news because it has the best inlet flow of any Triumph six-pot. Burgess opened the inlet and exhaust ports, cut the inlet seats and reshaped the combustion chambers, finishing with a skim to raise the compression ratio from the factory 8.5:1.
While the block was bare it made sense to fit a number of other uprated parts, so I started with a spin-on oil filter conversion (as well as being messy to change, the original paper-type filter is known to cause low pressure on start-up). Next was the heavy cast exhaust manifold, chucked out in favour of one of Chris Witor’s easy-breathing 6-3-1 stainless-steel tubular headers. That gave me the perfect excuse to ditch the factory starter motor and fit a high-torque version from Powerlite. It’s lighter, more energy efficient and torquier, and the new unit is tiny, fitting better behind the manifold.
With the car immobile, I took a box of components to a local powder-coating specialist, who finished the timing cover in black and the rocker cover in silver, and shot-blasted the waterpump and thermostat housings. I also ordered a new radiator overflow bottle and the effect has improved the look of the engine bay considerably. It would have been a shame to spend so much money and still have an engine that looked as if it had been dredged from a lake bed!