Last year I was able to drive the latest gas-turbine car by Chrysler International, as were journalists all over Europe. Some writers were critical after this experience, complaining of interior and external noise, poor response to the throttle, lack of engine braking. Others were in raptures. Personally, as the experience was so brief, I prefer not to commit myself at this stage, beyond the “stop-press” comments MOTOR SPORT published at the time.
But with the issue of 50 of these Chrysler coupés to selected customers and the great performance of the Rover-B.R.M. at Le Mans, the gas-turbine-powered automobile is obviously coming closer to reality, so it is worth looking at the progress made by Chrysler in this field.
The earliest work on gas-turbine engines carried out by Chrysler in the United States dates back to pre-World War II days when an exploratory engineering survey was conducted. At that time it was determined that neither materials nor techniques had advanced to the point where cost and time of intensive research would be warranted.
At the end of World War II studies of completely new concepts in gas-turbine design were initiated. In the autumn of 1945 Chrysler was awarded a research and development contract to create a turboprop engine for aircraft. An engine achieving fuel economy approaching that of aircraft piston engines resulted.
At the termination of this contract in 1949 Chrysler engineers returned to their original objective – the automotive gas-turbine engine. In the early 1950s experimental gas-turbine power plants were operated on dynamometers and in test vehicles. Active component development programmes were carried out to improve compressors, regenerators, turbine sections, burner controls, gears, and accessories.
In March 1954 Chrysler announced the development and successful road testing of a production-model Plymouth sports coupé which was powered by a turbine engine. This marked the first attempt by an American automobile company to install a gas-turbine engine in a production car. Exactly two years later, in March 1956, the first transcontinental journey of a passenger car powered by a gas-turbine engine was successfully carried out in the United States by a 4-door Plymouth saloon. The car left New York City on March 26th. Four days and 3,020 miles (4,862 km.) later it completed its cross-country endurance test when it arrived in Los Angeles.
Basing their calculations on extensive test data and performance results of the 1956 cross-country trip, Chrysler engineers then designed and developed a second turbine engine. It was installed in a standard production Plymouth 4-door hard-top and in December 1958 it made a 576-mile (927 km.) test run from Detroit to New York.
The third generation of the Chrysler turbine was introduced in 1961 in three different vehicles. The first of these was an experimental sports car called the Turboflite – an “idea car” which aroused a great deal of interest in the United States and in Europe, where it was displayed at the Paris, London and Turin Shows in 1961. The second of the vehicles was a 1960 Plymouth which was standard except for minor exterior styling modifications. The final member of the trio was a 2 1/2-ton Dodge truck, which was a standard production vehicle. The engine in the truck was basically the same as the turbine power units fitted in the two passenger vehicles.
After months of tests and further development work the CR2A gas-turbine engine was installed in a modified Dodge model called the Turbo Dart. This car left New York City on December 27th, 1961, to begin a coast-to-coast engineering evaluation run. After covering 3,100 miles (4,989 km.) through snow-storms, torrential rain, sub-zero temperatures and 25 to 41 miles (40 to 60 km.) per hour head winds, the car arrived in Los Angeles on December 31st. The turbine had not only lived up to all expectations but had exceeded them. An inspection showed every part of the engine to be in excellent condition. Early in 1962, a Plymouth called the Turbo Fury joined the Dodge and both vehicles undertook extensive consumer reaction tours across the United States. The Turbo Dart was demonstrated in Europe outing the Paris and London Shows of 1962.
In May 1963 Chrysler announced that approximately 200 motorists in the United States would drive a Chrysler Turbine car for periods of up to three months under a unique no-charge use agreement. Fifty cars were to be built to enable the company to carry out this unprecedented consumer research programme.
Two weeks after this announcement the Chrysler Turbine – fitted with a new engine – was introduced at a Press preview in New York. Shortly afterwards Chrysler International announced that a Chrysler Turbine would be taken round the World, to be demonstrated and test driven in 23 major cities on five continents. The 1963 Chrysler Turbine programme marks a milestone not only in the Chrysler turbine research and development story but also in world automotive achievement.
Chrysler claim for their turbine car many advantages, which include 80% fewer parts than a piston engine requires, practically no toxic carbon-monoxide, vibrationless running, warming up not needed when starting from cold, heat available immediately, no pistons or cylinder walls to lubricate, no cooling water to freeze or boil, elimination of ignition timing, long life of the single igniter plug, operation possible on a wide variety of fuels and little maintenance required, as well as the turbine advantage of independently rotating compressor and first-stage turbine, so that these keep on idling even when a sudden overload has stopped the power turbine.
The Chrysler A-831-2 turbine engine is made of cast aluminium, cast iron, CRM, and ferritic stainless steel. Some of the materials used – notably in the regenerator (heat exchanger) seals, internal sheet metal parts and gas-flow passages – have been specially developed by Chrysler technologists in the United States.
Without accessories, the engine is 27 in. long, 35 in. wide, and 27 in. high. Overall length is increased from 3 to 9 in. according to the type of accessory-drive used. Without transmission, the engine weighs only 410 lb., some 10% less than its predecessor, as well as being more efficient. Maximum temperature at the first stage nozzles is 1,700° F. (927°C.), and in a very small zone inside the burner it reaches 4,000° F. (2,204° C.). Exhaust temperature varies according to atmospheric temperature, but is about 180° F. (87° C.) at idling speeds, and 500° F. (260° C.) at full power.
A conventional 12-volt, 70-amp./hr. battery is used to provide electricity through a voltage regulator. For the sake of simplicity a combined direct current starter-generator unit is used.
Great ingenuity has been shown in the production of such a compact, efficient turbine engine. The normal turbine wheel has separate blades, machined to ultra-fine tolerances, and capable of being rotated in concert in their own seatings, so that as speed and power output build up or decline, the angle of the blades can be altered to make the most effective use of the gas flow. Chrysler produces a one-piece turbine wheel, and gas flow efficiency is obtained by means of a variable nozzle system which intercepts the gas flow before it reaches the wheel, directing it on to the turbine blades at the most effective angle. By this means also, a high degree of engine braking is achieved without danger of damage to the turbine wheel.
The vanes of the variable nozzle assembly are located on radial shafts which engage a ring gear through a small arc. The ring gear itself is operated by the accelerator pedal through a cam-controlled hydraulic servo-actuator. Whenever the car is moving faster than 15 m.p.h. and the foot is lifted from the accelerator pedal, the nozzles direct the gas flow against the direction of tne turbine wheel’s rotation, producing the desired braking effect.
Chrysler’s twin-regenerator engine is rated at 130 h.p. at 3,600 r.p.m. output shaft speed and 425 lb./ft. torque (59 mkg.) at zero output shaft speed, under ambient temperature conditions of 85° F. (29° C.) and 29.92 in. Hg. atmospheric pressure.
Unlike a piston engine, which is tested and rated as an individual unit without transmission or accessories, the gas turbine engine is rated as a complete package.
By such standards, the turbine power plant gives a power performance comparable to a piston engine with an output in excess of 200 hp.
The single-stage centrifugal compressor has a c.r. of 4 to 1 and 80% efficiency. The first-stage turbine is an axial single-stage unit of 84% efficiency and the regenerator consists of two rotating cellular honeycomb discs of 90% effectiveness. The burner is of single-cam reverse flow type, going to 4,000° F. (2,204° C.) maximum temperature to give 95% efficiency. Maximum first-stage turbine speed is 44,600 r.p.m., maximum power is developed by the second-stage turbine at 45,700 r.p.m. and reduction gears reduce this to 4,680 r.p.m. Maximum regenerator speed is 22 r.p.m. Air flow through the compressor is 2.2 lb./sec., regenerator outlet temperature 1025° F. (552° C.), first-stage turbine inlet temperature 1,700° F. (972° C.), and exhaust temperature varies from 190° F. (87° C.) when idling to 500° F. (260° C.) at full power.
This gas-turbine drives through a modified TorqueFlite 3-speed automatic gearbox without torque converter, to a two-pinion 3.23-to-1 back axle. The Ghia 4-seater coupé into which this 130-b.h.p. gas-turbine is installed has power steering, brakes, and window lifts.
The front end has its functional elements merged into the form of the car. The 7-in. headlights are set in bold outlining rings. These simulate a bladed turbine wheel. The grille is designed with horizontal aluminium bars framed in stainless steel. The headlamp housings serve as the front bumpers with additional protection from the heavy gauge number-plate housing.
In profile, a low, thin roof silhouette rests on the car’s narrow front, and wide rear pillars. The low appearance is emphasised by a subtle horizontal creaseline along both sides of the body. It has been produced in only one colour: turbine bronze. Its roof and rear pillars are covered in black vinyl.
The turbine symbolism is repeated at the rear end in the ribbed tubes housing the reversing lights. These, and the tail and indicator lights are recessed into the massive bumper area.
Seats, doors, trim panels and instrument panel are covered in rich, copper-coloured leather. A bright aluminium console tube runs from front to rear between the seats. Headlining is off-white perforated vinyl.
The instrument panel is airfoil in shape and is partially leather-covered. The cluster comprises three pods mounted over the steering wheel. Instruments contained are: the turbine inlet temperature gauge, speedometer, tachometer, ammeter, fuel gauge, clock, and oil-pressure gauge.
Controls are mounted on the console tube within easy reach of the driver. The car’s bucket seats are covered in copper-toned leather. Those in the front have copper-coloured safety belts.
Among interesting chassis features in the turbine car is a front suspension unit that enables engine, transmission and suspension to be removed as a single unit. The front suspension has shock-absorbers located within coil-springs as well as control arm pivots to ensure a smooth ride. The rear suspension has two fore-and-aft leaf-springs and shock-absorbers extending rearward and upward from the axle to the body. The power brakes have a self-adjusting servo-type assembly. The hydraulic master cylinder is operated by an air booster since no vacuum is available from the turbine engine. Air pressure is provided by a continuous-duty, electric-motor-driven compressor and reservoir tank. The body of the Chrysler Turbine is unit constructed. Its upper structure includes sturdy box-section front and rear pillars with box-section rear window header. Further roof support comes from a channel roof bow. Bonnet and boot panels are constructed of adhesive bonded aluminium panels. The under-body has fore-and-aft aluminium strips to protect the exhaust ducts. These take the place of pipes on a conventional car.
The 14-in, wheels are fitted with special rayon cord tyres. These have a decorative “turbine wheel” design on white sidewalls.
The most significant advance among the accessories is featured in the heater assembly. This incorporates an “instant heat” gas-to-air exchanger. Instead of providing heat by hot water, turbine gases pass into a heater core which transfers its heat to fresh air for the passenger compartment. Since there is no engine vacuum the heater controls work on air pressure tapped off the compressor diffuser.
Driving this car involves no special technique, except that what would normally be called neutral in the gear gate is labelled IDLE, and the accelerator pedal must not be depressed until the engine is running under its own power. Instrumentation is conventional except for the high speeds registered on the tachometer (safe maximum, 44,610 r.p.m., but an automatic fuel control prevents over-revving) and the need to keep the reading at not more than 30,000 r.p.m. at 60 m.p.h., the first-stage turbine being to some extent independent of the second-stage turbine and transmission speeds. Also, temperature readings relating to gas-entry at the first-speed turbine can go as high as 1,800° F. (982° C.) under full acceleration.
Chrysler International concludes its publicity literature on the car with these words: “Listen for it. The exciting new sound of the Chrysler Corporation Turbine Car.” How soon will this sound become familiar ? – W. B.