How to turn your TR2-3 into a TR6 beater!

Did you know that the Triumph TR has its roots in Morgan? After Standard Triumph director Sir John Black failed in his bid to buy the Malvern sports car outfit, he decided to make his own and take on all comers whatever their badge. While some may agree with the American doctrine “There ain’t no substitute for cubic capacity” a TR2-3 can be made to perform just as well as a six-cylinder TR5/6 and, thanks to a lighter engine, handle better too. Here’s how!

BEFORE YOU START

Before any performance mods, it’s vital to ensure that any car is in sound condition and TR2/3/3A/3Bs are no exception. A solid rot free chassis is essential; early TRs employed a unique water drainage system from the bonnet area, lest people with a preference for aero screens might not be keen on wet laps. Water drawn backwards between the bonnet and wings, drained through drainage channels in the scuttle – you can guess the rest! Other rot areas include outriggers, costing an easy £2000 to right because the bodyshell really needs to be removed for a proper repair. The front apron floors and sills are other worry spots.

If the chassis is bad or patched once too often, you can have a new one made up. German & Peschl Classic Sports Cars, based in Cologne, gives a 10 year warranty with its rebuilt frames. CTM Engineering of Southampton specialises in repairs or new chassis frames. Remember, a new chassis not only rids you of rust problems but it will be inherently much stiffer and aid rigidity, essential if you intend track work.

Mechanically, the TR is a tough design but keep on top of the cooling system and fit an uprated radiator along with electronic ignition to keep the timing spot on. Triumph used to advise checking and adjusting front hubs every 12,000 miles plus repack frequently if used in competition. Likewise, over-maintain front trunnions (use oil not grease if possible) to contain wear.

HOTTING UP

The trusty tractor-derived four pot can see around 130bhp for reliable, tractable (excuse the pun) road use and that’s good enough to see off many TR6s. Good, cheap upgrades start with a simple session on the rolling road, paying close attention to optimum mixture and ignition settings before adding better air cleaners and a sportier exhaust. There’s fuel injection available, but it’s too exotic, pricey and over-the-top for most owners, unless you intend to race.

The logical starting point is a larger 2.1-litre TR4 engine, but any unit will be fine if the head is improved; £959 Stage II from Moss, £1950 for an alloy alternative. Don’t be tempted to raise the compression ratio too much either as anything over 11:1 will put the engine under considerable stress and give scant extra gain for road use.

TR4 engines are interchangeable plus offer more option choices in terms of upgrades. Moss, for example, offers a range of aftermarket camshafts from Road to Race. Prices start from £227 although bear in mind that the racier you go, then the more you’ll lose lots of that lovely low speed pull. A roller rocker shaft kit (£550) gives less gains but the engine doesn’t need to be stripped to fit – so you choose.

A brace of Webers certainly looks the part but on a mildly tuned engine kicking out under 130bhp is hardly warranted. Twin 1.75in SUs are ample for most uprating purposes along with an extractor manifold and a single-silencer exhaust set up.

The beauty of this ‘wet liner’ engine is that reboring is super easy by simply replacing the liners and there’s some fair stretch on offer in that block.

TRGB, for instance, markets an 89mm piston and liner kit which takes the engine out to a lusty 2.3-litres for just over £450.

The more adventurous type can see 2.5-litres using TR Enterprise’s 92mm pistons, while famous Morgan racer Chris Lawrence took his TR engine right up to a mighty 2.7-litres although the gains of exceeding 2.3-litres don’t warrant the cost for many owners, say TR experts. Whilst the engine is in bits, buy and fit TRGB’s improved rear oil seal kit for £60.

Lightening the flywheel to improve throttle response is a good cheap mod and worth doing even on a standard engine if you are replacing the clutch assembly but it’s better to start with the later TR4A one as it has more scope for shaving – at least 10lbs says TRGB, possibly more.

Biggest new bang for your buck can come from supercharging where a £3500 outlay normally sees a whopping 40 percent power hike, says Moss, plus it’s a simple bolt-on job that’s simple to remove and not leave a trace.

A typical fast road engine tune will see not only a reliable 120bhp, but also 160lbft of torque. Modifying further, perhaps for competition work, is quite a bit more involved as well as expensive because, as robust as this engine is, the bottom end can’t really take much more and ideally needs a steel crankshaft, conrods and so on. Performance engines typically start from £3500-£5000, depending on what you want and where you shop.

HANDLING THE POWER

Having made this Triumph go, it’s wise to ensure it stops! Later cars with their disc brakes are fine but TR2s and early TR3s utilised drums all round. Get those front ones off, replacing with the discs from a later TR is the first step. Simply slotting in uprated pads (such as EBC or Mintex types) usually suffices and shouldn’t need upgrading further for road or even mild competition work. If you want more than fit TR4 discs – but not TR6 ones as they are strangely slightly smaller… More exotic aftermarket alternatives include Willwood callipers etc.

Those governed by historic FIA regs, which outlaw certain mods, may require you to retain the drum brakes; speak to a TR expert as there are ways around this such as uprated linings (Mintex has recently launched a full range for classic types, by the way) and finned alloy brake drums to reduce heat soak and fading.

Latest tweak for early TRs comes from Revington TR with its geometry modification kit that corrects the quirky inherent negative Ackerman angle pre TR4 cars suffered from.

TR’s 2-3B, you see, were designed with very a odd steering geometry insomuch as they have what’s called negative Ackerman angle, set as it is for very good reasons considering the chassis, rear springs, lack of front anti roll bar, zero caster and tyre availability at the time, stresses Neil Revington.

Over the years, folk have tried using TR4 steering levers. But whilst correcting the Ackerman angle, they bring other “hideous geometry errors” that it is really not worth doing, he adds.

Revington introduced corrected TR2-3B steering levers in 1993 in conjunction with its suspension packages but could only offer the levers on an exchange basis due to lack of available stock of steering levers. “Now that we have plenty of stock we are pleased to be able to offer the kit to all TR2-3B owners irrespective of what steering system they have, the original set up or a rack conversion. Our rack conversion has always been supplied with these arms,” Neil told us, adding that as far back as 1992 his company employed a specialist suspension designer to look over the TR suspension and propose improvements. “This we did at considerable expense and the Ackerman alteration was one of a package of improvements, the other major one being our adjustable upper fulcrum.”

The kit costs £132.88 and consists of new tie rods. If Revington’s rack and pinion steering conversion kit is already fitted (which brings it in line with the TR4 and transforms the tiller) a tweak is needed as the mod is already ‘designed’ in. A further benefit is that they incorporate a slight drop in the position of the outer ball joint, so reducing bump steer; TR4A-6 type upper wishbones also help in this respect.

Revington TR sell chassis strengthening kits to add rigidity and improve the handling but require welding into place and is more for competition purposes. Before you decide on doing this, bear in mind that fitting a roll cage also stiffens the chassis somewhat and so will dictate the final spring and damper settings. If you want to lower your TR then the company’s ‘Race Sump’ might be wise addition!

Gary Bates of TRGB suggests lowered and uprated springs along with better damping – Koni, Spax or Gaz shocks come recommended. You can convert the front end to TR6 spec but there’s little benefit given the effort involved, he adds although a TR6 spec anti roll bar is a good cheap mod. What top TR specialists do agree on is the worth of firmer polyurethane bushes fitted throughout the chassis. Costing around £500 in parts and can be a pig to fit, but both TRGB and Revington (01823 698437/ http://www.revingtontr.com) say it’s probably the best single mod you can carry out on any TR.

At the other extreme Neil sells a full rebuild kit with all the uprating you need for some £1700. Four-hundred quid buys a rack and pinion steering conversion kit from TRGB, but takes about 20 hours to fit – if you want this you may need the electric fan mod.

Both TRGB and TR Enterprises say ditching the perfectly effective overdrive for a modern five-speed may not be necessary as the overdrive can be uprated plus also provides a practical seven-speed solution where overdrive second is an ideal ratio for tight hairpin work.

If you want five-speed it can be a costly exercise as conversions using a modified Toyota Supra ‘box cost some £4400. On the plus side, it’s a straight bolt on meaning it can be reversed to original without detection. Ford Type Nine based conversions start from £3300 (Moss), although some reckon the Sierra ratios are ill chosen. Another option is the Rover LT77 transmission. If you retain overdrive, Revington’s Logic Overdrive Device, that replaces the existing on/off switch and disengages overdrive when you shift-up a gear, is a good upgrade.