Howmet turbine - 1969
The idea of a turbine engine, was accepted as nothing out of the ordinary for a single seater at the beginning of 1968 but a jet-engined sports car was something else, although Rover combined with BRM to build a Le Mans car which finished, if not very quickly. With complicated rules to work to most people decided to give the turbine engine a miss but Ray Heppenstall persuaded the Howmet corporation to sponsor a team of cars in the World Sports/Prototype Championship for 1968. Using a chassis supplied by McKee and a Continental turbine engine originally intended for a helicopter the Howmet TX was completed in late 1967 and in tests at Daytona Heppenstall lapped "the banked oval at an average speed of 176.58mph. Satisfied with this outing and other tests the team entered a car for the Daytona 24-hour race. The car was running well up with the leaders until the turbine waste gate stuck at a crucial point and driver Ed Lowther ran up the banking and eliminated the car against a wall.
Moving on to Sebring the car contested the 12-hour race but severe overheating plagued the engine, a temporary cure, being to throw buckets of water over it, which made the more knowledgeable step back a few paces; the engine disliked this treatment and eventually broke its engine mountings through vibration.
The team created quite a stir when they brought the Howmet to England for the BOAC 500 at Brands Hatch, but after attracting more attention than some of the faster cars like the GT 40's and Porsches Dr. Dick Thompson crashed it into the bank at Druids very early in the race after the throttle stuck open. The car would have won the £1,000 prize for the first turbine car to finish since it was the only one there! The Howmet was proving to be quite a fast car even on twisty circuits where most people thought that its lack of engine braking and slow throttle response might hamper it, but its big and seemingly incurable problem was its very high fuel consumption which would have forced it into the pits every 45 minutes at Brands Hatch, had it lasted that long! The piston-engined cars were going well over an hour, most of the Porsches lasting 1.5 hours before stopping.
The team gave the rest of the European season a miss apart from Le Mans which was held at the end of the year due to the May and June riots. Back in the USA the team entered some minor SCCA races, Heppenstall winning a 25-lapper at Huntsville, Alabama, while later on Heppenstall and Dick Thompson won the Marlboro 300-mile race in Maryland at an average of 64.75mph on this short, tricky course. Then in the six-hour Watkins Glen road race counting towards the World Sports/Prototype Manufactures Championship Heppenstall and Thompson finished third overall and won themselves four Championship points. They were helped by the retirement of most of the factory Porsches but the second Howmet driven by Hugh Dibley and Bob Tullius was in fourth place until it suffered differential problems and dropped back to 12th place.
At Le Mans "the team entered two cars but they had a disappointing race because Dick Thompson crashed his car and rolled it to put it out of the race, while the Dibley /Tullius car was disqualified due to falling too far behind time when they lost some three hours with wheel-bearing problems. Following Le Mans the Howmet Corporation obviously decided to abandon the project and the cars have not appeared since.
When it was decided to go into racing Heppenstall thought it best to use an existing well-proven chassis and settled for the Group 7 chassis built by the McKee Engineering Corporation which had gone quite well in open form in CanAm races. This is a fairly conventional tubular steel space frame, designed for mid-engined applications. Double wishbone front suspension with outboard mounted springs, in conjunction with lower wishbones, single top links and radius arms at the rear, form the suspension medium. Braking is by Kelsey-Hayes disc brakes and steering is by rack and pinion. McKee magnesium wheels shod with Goodyear tyres are fitted all round. The body, built from aluminium supplied by the Howmet Corporation is of coupe construction to comply with the 1968 Group 6 rules, having air intakes above the roof for the rear-mounted turbine.
The engine used in the Howmet. is the TS325-1 Continental shaft turbine engine. Originally designed for helicopter application this engine proved ideal for the purpose and fell just below the necessary 3-litre equivalent under FIA rules. The engine has one centrifugal stage and one axial stage compressor followed by an annular type combustor, a two-stage gas generator turbine and a single stage free-power turbine. Weighing in at a modest I70lb die engine gives 330 horsepower at 6,789rpm after reduction gearing, but the gas generator runs at 57,500 rpm and the power turbine at 44,000 rpm. Howmet also supplied the turbine blades for the engine.
The only major modifIcation to the engine was to add a wastegate valve between the gas generator turbine and the power turbine, which improves throttle response by varying the hot gas flow to the power turbine, excess gas being vented to atmosphere. This wastegate stuck on several occasions before it was finally cured, causing the accident at Daytona.
Although the turbine-engined racing car has received a temporary setback due to too severe limitations by the ruling bodies to try and keep the piston engine competitive it is pretty certain that the turbine will eventually come to stay.
More Le Mans Cars from the 60ies onwards
wheelbase 7 ft 9 ins
track front 4 ft 9.5 ins
track rear 4 ft 7 ins
height 3 ft 4 ins