D’ELEGANCE: HI-TAC SUZUKI

Former Norton racing boss Peter Inchley developed this thermo-siphon, water-cooled Suzuki racer

Water-cooled two-stroke racer built by gifted engineer Peter Inchley

This unusual project was started in 1972 by the boss of Hi-tac engineering, Peter Inchley. He was a former national racer and ex-norton Villiers Performance Race Shop chief who had helped develop the AJS Starmaker and race-developed the Norton Commando and AJS Y4 scrambler. Inchley realised that water-cooling was preferable to air-cooling for two-strokes as engine temperature could be kept more stable.

He designed a thermo-siphon kit for the T500 (before Suzuki’s own water-cooled TR500 MKIII) in which heat exchange was based on natural convection to circulate the water without the need of a mechanical pump. In original specification the kit comprised of water-cooled barrels (with spun, cast-iron liners which were removable for porting, etc), a close-ratio gearbox, CDI ignition, Ni-cad battery, trigger ignition to replace the original contact breaker points, and expansion chambers.

The first year’s kit had a single Amal 38mm carburettor (twin carbs were fitted later) which provided excellent flexibility with no noticeable loss in top end power. The CDI ignition allowed a 14,000rpm rev limit. The standard air-cooled motor provided about 60bhp with the prototype modified version reaching 72bhp. Later twin-carb versions made 82bhp.

This bike was initially tested by Barry Sheene, but there were countless problems with the ignition system, resulting in a spate of seizures. The engine was then placed in a Seeley frame and raced by Charlie Sanby.

For 1972 Sanby, one of the top national racers in the UK, was offered a 750 works triple to ride at the TT by Suzuki team boss Rex White, but declined as he’d already agreed with Inchley and racing team owner Frank Higley to ride their Hi-tac Suzuki in the Senior TT. Sanby was clocked at 164mph on the Island, so the bike had plenty of speed – and he finished tenth on what was essentially a development bike. He then raced the

bike on short circuits and continued to campaign it into the 1973 season when he finished third in the Senior TT, averaging just over 100mph – despite the bike cutting out at Bedstead on the final lap, either due to lack of fuel or faulty ignition. The race was won by Jack Findlay on a TR500 MKIII, the first year Suzuki had switched to water-cooling for the two-stroke twin. Sanby also finished third on the Hi-tac Suzuki during the following weekend’s Mallory Post TT races, behind Suzuki-mounted winner Barry Sheene and Mick Grant.

However, the early spate of seizures tarnished the Hi-tac’s reputation, which meant a lot of development money and credibility was lost and the project died. Inchley turned his attentions to kart racing, tuning the Villiers and Starmaker engines that he’d had so much success on in his early career with Norton Villiers.

The current owner of the bike has fitted a water pump, in line with the more relaxed pre-race procedures in classic racing events.

Photographed in southern England, 2018.

‘CLOCKED AT 164mph ON THE ISLAND, THE BIKE HAD PLENTY OF SPEED’

This bike was originally tested by Barry Sheene (although sadly unsuccessfully). The restoration by Nigel Everett (see CB May issue) is a fine job, though

Hi-tac kit included a close-ratio gearbox and expansion pipes. It cost £318 and at least 14 were manufactured before Hi-tac ceased production at tyhe end of 1973 LEFT: Hi-tac boss Peter Inchley – seen here testing – developed a water cooling kit for the T500 before Suzuki came out with their own water-cooled TR500 LEFT: Single 38mm Amal Concentric carburettor gave a good combination of top-end power and flexibility, although twin carburettors were fitted to later developments of the Hi-tac

The Hi-tac was raced in the 1972 and ’73 seasons by Charlie Sanby, one of the top UK national racers of the day. He finished third in the ’73 Senior TT on the bike

The bike’s Krober electronic ignition was its Achilles heel, causing piston disintegration and seizure. Inevitably, confidence in the project suffered and its demise became inevitable