Triumph TR4

Which classics still have the potential to get up and go? Steve Rowe remembers the cars, the tuners and the tweaks and tells why they’re still hot!

Launched with racing competitions in mind, the TR sports cars are still popular with those who enjoy the occasional spin on the track, as well as on the road. Introduced in the same year as Jaguar’s E-type, the TR4 represented an equally major step forward for Triumph. Based on the TR3 chassis but extensively modifi ed, the 4 was wider for a more civilised cockpit. The biggest change came in 1965 when the independent rear suspension from the 2000 saloon was grafted on to make the TR4A. Together with a slightly plusher cockpit, the A was a softer, easier riding car although hard core drivers like the better feel of the earlier stern. There was also a 100lb weight penalty which hindered perform-ance a little from that longlasting big four which was taken out to 2138cc for the TR4 (although some cars used the earlier 2-litre unit from the TR3 to confuse matters!). The TR4 offers all the style and character of the six pot TR5 and TR6 but without the fuel injection hang ups – or cost. And with subtle tuning can be made to go even better!

Get One Now

For far too long the TR4 lived in the shadows of the six pot TR5 and TR6 but this has changed of late and prices can match its smoother six pot brethren although typically prices hover around the £6-8000 mark for an average car; there’s little difference between the TR4 and the later 4A as condition counts the most. Rust (and the resultant bodging) is the biggest concern to both the bodywork and the chassis frame; if the latter is so rotten the car will bend in the middle (check for uniform panel and door gaps) but at least new frames or replacement sections are freely available. Problems sometimes occur on the 4A chassis where the differential unit is mounted. Mechanically the TR is as tough as the tractor that shares the same basic engine and because it’s has renewable cylinder liners, it can be resleeved time and time again as long as the crank is okay and doesn’t suffer from the end fl oat problems that always blight Canley’s cars. Front suspension can wear badly if neglected. If replaceable trunions are left to wear due to lack of proper lubrication the vertical link will also be affected and be expensive to put right.

Hotting One Up

Back in the 1960s, competition-minded TR buyers would head to the likes of SAH Accessories in Leighton Buzzard, who used the TriumphTune name to sell high performance components for the TR4. The company still exists under the banner of the Moss Group, still selling Triumph performance parts. Low-cost upgrades for daily use included fi tting an SAH four-branch extractor manifold, as used on ‘works’ rally cars, which could help to add 8bhp to a tuned 100bhp engine. If you had a bit more to spend, you could fi t a gas-fl owed cylinder head and a polished inlet manifold. For an engine-out upgrade, you could fi t a high-lift racing cam and perhaps an external oil cooler to help keep everything in check. With all these changes you might now be seeing around 120bhp. Today, several companies still specialise in modifying TR4s, including Racetorations in Lincolnshire and Revington TR in Dorset. We spoke to Neil Revington for an up-to-date overview of the tuning options. Moving on to the engine itself, once there are a number of measures you can take, together costing less than £1000, which will make your TR4 run much smoother and more reliable, possibly even adding a few BHP into the bargain, but this is not the main aim. Fitting electronic ignition is a good starting point and, at the same time, Neil recommends Magnecor plug leads Also K&N or Pipercross air fi lters are a good option. A new electric fan is a good idea and it’s also worth adding a thin-belt conversion to get rid of the standard powersapping wide fanbelt. For the ultimate in smooth running, Revington TR also sells a full fuelinjection system, for around £3000. This helps to provide a much smoother fl ow of power, in all conditions – like the TR6 but with modern 24-7 dependability!

Today, relatively few owners want to tune their TR4s up to full race spec, but companies like Revington TR and Racetorations can still do this for you. Darryl Uprichard of Racetorations categorises his company’s performance modifi - cations for the TR4 into three categories, fast road cars with up to 130bhp, track/road cars with around 160bhp and full-on race cars with around 190bhp. His company will rebuild your TR4 engine to either of the above specifi cations, with 130bhp engines costing from around £3500, 160bhp engines from around £5000 and 190bhp units from upwards of £12,000. There are a number of different ways to approach each engine and Racetorations fi nd out exactly what the customer is looking for, before deciding on the right modifi cations. Performance alterations will typically start with new cylinder liners and pistons, taking out the bore to 89mm (up to 2.3-litres is possible with this engine-ed). Darryl explains that the spigots at the bottom of the cylinder mean that the liner is thinner here, so taking the bore out to more than 89mm means signifi cant work to the bottom of the engine. For those after 160bhp or more, engine modifi cations will also include forged pistons, a modifi ed performance head, a hairier camshaft and billet steel con-rods. A roller rocker set could also be added, with Darryl explaining that this won’t add to the performance fi gures but will reduce heat build-up. For those after the full 190bhp, Racetorations can build a high-performance engine that will run to over 7500rpm. At this level, Daryl says that the standard crankshaft is not really up to the job, so he fi ts a new high-performance steel crank with new bearings in the same place as the old bearings. Other modifi cations are designed to lose weight in the engine’s moving parts, as well as making them tougher, for instance new lightweight fl ywheels and con-rods etc. External engine components also get the works, with, for instance, a 7psi electronic fuel pump and fi lter added to replace the standard mechanical unit. A session on a rolling road/dynometer to fi ne tune the engine, even in light tune, can pull out a few added horses plus run better. Racetorations put all completed engines on its own dyno for three days, running them in and checking the performance fi gures, using the same carburettor/exhaust manifold set up that will be used once the unit is fi tted. Bear in mind that, if you’re fi tting such a highperformance engine to your TR, then the entire transmission and suspension system will also have to be upgraded, as the old standard components, will soon fail with any serious use. Like the gearbox! If originality isn’t your thing, then the later Rover LT77 fi ve-speeder can be fi tted, as can the ever popular Ford Sierra and Toyota Supra ‘boxes. If you’re sticking with overdrive, Neil recommends fitting a special Logic Overdrive device costing £84. This is a ‘smart’ activator that replaces the existing on/off switch and disengages overdrive when you shift up. In use, when you change up from second-gearwith- overdrive, you then hit third-gear-without-overdrive, until you next tap the switch to engage it. Basically, changing gear disengages the overdrive, making for more fl exible driving without the danger of being in overdrive when not needed.