Bristol 411 Series 1-5

Manufacturer	Bristol Cars
Production	1969 to 1976
Produced	287
Class	Sports Car
Layout	FR layout
Engine	6,286 cc OHV V8 6,556 cc
Transmission	3-speed automatic
Wheelbase	2,896 mm (114.0 in)
Length	4,902 mm (193.0 in)
Width	1,727 mm (68.0 in)
Height	1,460 mm (57.5 in)-1,473 mm (58.0 in)
Curb weight	1,676 kg (3,695 lb)-1,712 kg (3,774 lb)

The Bristol 411 is a sports car which was built by the British manufacturer Bristol Cars. 

History

The Bristol 411 was a two-door sedan by British car manufacturer Bristol Cars, replacing the Bristol 410 in 1969 and produced until 1976. In the course of the seven-year production period, the model successively underwent numerous technical and visual modifications. Some of these changes were so serious that, based on the manufacturer's previous practice, they would actually have justified a new model designation; at least that was the case for the change from 411 Mk.2 to Mk.3 and from Mk.3 to Mk.4. Nevertheless, Bristol retained the designation "411" for all variants and differentiated the individual models according to series (Mark 1 to Mark 5). The model is currently being re-offered as the Series 6 Coupé by Bristol Cars.

Introduced 1969. Max. speed 140 mph approx. Acceleration 0—70 mph in 9-5 secs approx. Fuel consumption 14—18 mpg approx. Chrysler 6.2-litre engine with Torqueflite automatic transmission and limited-slip diff. Front suspension has been modified to accommodate radial-ply tyres. Electric windows now standard. Front seats redesigned for increased comfort. Bristol’s are built in small numbers for those who still appreciate cars individually built and tested at an unhurried pace. With a massive steel chassis carries bodywork in aluminium. Steering is power-assisted. Fitted later with the larger 6.5-litre Chrysler engine runs on three-star fuel and has an electronic injection system with no contact breaker points to adjust 12-volt negative-earth ignition system; 71 amp. /hr. battery, high performance alternator charging system. Spare wheel, battery, fuse boxes, are mounted in the front wings. The closed box section chassis, welded steel construction with 3 cross members, forming a very robust structure of great protective strength; open propeller shaft; Bevelift Jacking system using built-in jacking points. The front suspension, independent by wishbones of unequal length with coil springs, telescopic hydraulic dampers, torsional anti-roll bar, rear suspension, torsion bar springs with Watts linkage, adjustable telescopic dampers. 

Replacing it was the much larger big-block B series engine of 6,277 cc (383.0 cubic inches) - as compared to the 5,211 cc of the 410. This much larger engine gave the 411 an estimated 30 percent more power than had been found in the 410. The 411 was capable of 230 km/h (143 mph). To cope with this extra power, a limited slip differential was fitted so that the car skidded much less at high speeds. The Chrysler capacity 6,277 cc. (383 cu. in.), with compression ratio 10:1, power output 335 (S.A.E. gross) b.h.p. at 5,200 r.p.m., maximum torque 425 (S.A.E. gross) Jb./ft. at 3,400 r.p.m. With chain driven camshaft, hydraulic tappets; full flow oil filter; Carter 4-barrel downdraught carburettor, automatic choke for cold starting; manifold heat
control valve for rapid warm up; large paper element air cleaner/ silencer with pressurized at 13 p.s.i. cooling system with capacity of 29 Imp. pt. (16.5 litre’s) and twin electric fans automatically controlled by thermostat ensure optimum cooling irrespective of engine speed engine incorporates 'Cleaner Air System', which reduces concentration of hydrocarbons and carbon monoxide in exhaust gas. Power-assisted steering, re-circulating ball type, 15.7:1 ratio, sealed ball joints; 15 in. 3-spoke steering wheel with an energy absorbing steering column designed to collapse axially at a pre-determined rate, anti-theft steering column lock operated by ignition key; Dunlop pressed steel, perforated bolt-on disc wheels with 5 in. rims, Avon radial ply tyres, 185 x 15 with tubes; separate front and rear hydraulic brake systems operated by tandem master cylinders, failure warning device connected to lamp on instrument panel. Self-adjusting, servo-assisted Girling disc brakes on all wheels, handbrake employs separate clamps operating on rear discs with automatic adjustment, pull-up type lever, mounted on floor between front seats, warning light indicates 'handbrake on' position and also checks warning circuit function. The mechanical parking lock working through transmission operated by gearchange lever.

Full 4-seater Saloon, the underside of body fully undersealed, inside of body selectively treated with anti-drumming material with welded steel structure and aluminium alloy panelling Available in single or duo-tone colours. With full width front and rear bumpers, windscreen and rear screen in laminated plate glass; door lights and quarter lights in toughened plate, hinged rear quarter lights; spare wheel housed in unique compartment in left-hand front wing; similar compartment on right-hand side houses battery, twin brake servos and fuse panel. The interior showed a number of important changes from the Bristol 410. The traditional twin-spoke steering wheel was replaced by a more practical three-spoked leather-wrapped wheel, which as a result of the traditional Bristol badge being removed from the front of the car, was the only place where this badge was retained.2 doors hinged on front pillars have burst-proof locks and are fitted with armrests, individual fully adjustable front seats with fully reclining backs, which tip forward to allow easy access to rear; individual rear seats accommodate 2 persons in comfort and have folding centre armrest. The interior upholstered in top quality hide over foam rubber cushions and backs, protective padding above and below facia panel, walnut veneered facia panel, instrument panel and door capping with pile carpet with soundproof underlays, for storage lockable glovebox, also pockets in doors, on rear of front seats and sides of rear seats, full width rear parcel shelf; courtesy roof light operated either by the doors or independent switch; 3 ashtrays; 2 cigarette lighters. Luggage boot, 19 cu. ft. capacity, with tool stowage shelf.

Through-flow heating and ventilation system provides fresh air at desired volume and temperature without necessity of open windows; air is fed to heater and/or 4 individually adjustable Cold air face level vents from opening below the windscreen, minimizing intake of traffic fumes, 4 slots at base of windscreen for demisting and defrosting; instruments, grouped in cowl in front of driver, have rheostat-controlled illumination and include: 4 in. diameter speedometer with trip recorder, 4 in. diameter tachometer, battery condition indicator, petrol gauge, oil pressure gauge, water temperature gauge and electric clock; warning lights for head lamp main beams, direction indicators, brake fluid level, petrol reserve, handbrake and manual override switch for cooling fans.

The sealed beam 4 head lamp system, outer pairs giving main and dipped beams, inner pairs main beam only with foot-operated dip switch; side and direction indicator lamps and side repeat direction indicator lamps; twin combined tail, stop and direction indicator lamps incorporating reflectors; twin automatic reversing lights; 2 rear number plate lights; automatic luggage boot light; dual 2-speed self-parking windscreen wipers, windscreen washers and twin wind tone horns. An interior convex driving mirror; combined direction indicator, horn and head lamp flash switch mounted on steering column; rheostat controlled, subdued, facia illumination, hazard warning system, and red reflectors on the trailing edges of both doors. Fuel tank mounted behind rear seat, isolated from car interior and boot by steel bulkhead, capacity 18 gal. (Imp.) (82 litre’s) including 3 gal. (13 litre’s) reserve supply controlled by
switch on facia panel; lockable filler cap; consumption 14-18 m.p.g.

The Chrysler Torque-flite gearbox has 3 forward speeds and reverse automatic transmission, with fluid torque converter, gives variable ratio drive incorporating intermediate gear hold, permitting engine braking, gears selected by floor-mounted selector lever with 6 positions: P (park, R (reverse), N (neutral), D (drive), 2 (second), and 1 (low), ratios (overall), low 7.52, intermediate 4.45, high 3.07, reverse 6.75, torque converter stalled ratio 2:1.

Over its seven years in production, the 411 showed a number of changes.

Bristol 411 Mk.1 

The Bristol 411 Mk. 1 was introduced in the spring of 1969. The main difference from the previous 410 was the use of a much larger engine. After eight years, Bristol parted with the proven 5.2-liter eight-cylinder and now relied on a 6.3-liter engine from Chrysler, which has been used in a similar configuration in the Jensen Interceptor for some time was used. The new engine was less heavily machined than the previous engine; Bristol used from now on essentially standard engines. The adaptation of the new engine to the car involved numerous technical detail changes. According to Bristol, the reason for changing the engine was primarily the fact that the new engine was easier to service because it was no longer necessary to adjust the valve clearance. However, it should also be noted that the larger engine resulted in a significant increase in performance. The engine now delivered 335 SAE hp.

The body had also been revised in numerous details. However, the changes were so subtle that they were hardly noticeable at first glance. The most conspicuous modifications concerned the side trim – only one instead of the previous two – and the rear end: Here the Humber was retained while fundamentally being retained-Rear lights now dispensed with the hinted rear wings; the rear of the car was designed smooth instead. Apart from that, Bristol had redesigned the shape of the radiator grille, modified the location of the auxiliary lamps and revised the curves of the front fenders. In the interior, the use of a new steering wheel was noticeable: instead of the traditional two-spoke steering wheel, a three-spoke model was now installed, in the hub of which a Bristol coat of arms could be seen.

The performance increased significantly with the new engine. The Bristol 411 had a top speed of 230 km/h, and the factory specified a value of 7 seconds for the acceleration from 0 to 60 miles per hour. According to Autosport magazine, the Bristol 411 Mk. 1 was the fastest production touring car in the world.

At launch, the Bristol 411 retailed for £6,997.

Bristol 411 Mk.2 

In the autumn of 1970, Bristol presented a first revised version of the 411. From a technical point of view, the main innovation was the use of an automatic instead of the previous manual level control. Externally, there were some very subtle changes that were to be understood as cosmetic modifications. For example, Bristol used new door handles and door locks that were slimmer. The Mk. 2 was produced until 1972.

Bristol 411 Mk.3 

With the introduction of the third series in July 1972, the Bristol 411 received a largely new body. Although the basic layout of the car and the design of the passenger cell remained essentially untouched, the front and rear sections were redesigned in a striking way. The radiator grille now went over the entire width of the vehicle. Integrated into this were four large round headlights from the supplier Lucas, whose diameter was almost 20 centimetres and which ensured excellent visibility when driving at night. Between the headlights was a chrome-plated radiator grille element, which was reminiscent of a toaster due to its shape. The item was then pressed into the Toaster Grill or Barbecue Grill called. It was retained in all subsequent 411 models and was also found - in a modified form - in the Bristol 412 and later in the Bristol Britannia and Bristol Brigand, but not in the immediate successor of the 411, the Bristol 603. In line with the new front end, the bonnet and front fenders were also revised. The latter were slightly raised to improve visibility of the front end. At the rear, the Humber Sceptre’s old taillights were replaced with new, rectangular taillights that were still vertical. Reversing lights were located on both sides next to the license plate. Overall, the 411 Mk. 3 made a much more contemporary impression than its predecessors without being particularly fashionable or modern itself.

A special feature were two twin exhaust pipes that protruded conspicuously from under the rear end panel of the car. These were dummies. In fact, the exhaust gases exited through a downward-flowing opening positioned about two inches from the end of the exhaust pipes. This design was to ensure that escaping exhaust fumes would not leave a mark on the Bristol driver's garage wall. The interior was classic. The style, the ergonomics and the good workmanship were unanimously praised in the press; only the use of British Leyland door handles was the subject of criticism.

The drive technology was only slightly modified. The 6.3-litre Chrysler engine was retained, but Bristol lowered the compression ratio to a ratio of 9.5:1 (instead of the previous 10.1:1) in terms of exhaust emissions and fuel consumption. This was associated with a reduction in engine power and also in driving performance.

Bristol 411 Mk.4 

A newly revised model, the 411 Mk. 4, appeared as early as autumn 1973. This time the changes were primarily of a technical nature. Bristol wanted to react to the slightly deteriorated performance that had resulted from the modifications to the Mk. 3. In order to ensure the well-known sportiness again, the company management decided - as was the case with Jensen - to use a new, even larger engine. However, the 7.2 Liter engine from Chrysler was not chosen, which caused countless thermal problems at Jensen. A 411 is said to have been equipped with this engine for test purposes; the choice ultimately fell on the smaller, lighter and similarly powerful 6.6 Liter engine from Chrysler. With a compression ratio of just 8.2:1, which enabled the use of regular petrol, the result was an output of 264 hp according to European measurement methods. The Mk. 4 thus achieved driving performance that was again at the level of the 411 Mk. 2. The same engine was used in the Bristol 412 introduced in 1974, a security convertible with a body by Zagato.

At launch, the Bristol 411 Mk. 4 was retailing for £8,973.

Bristol 411 Mk.5 

In the summer of 1975, the last expansion stage of the Bristol 411 was presented. The changes were purely cosmetic. The toaster grill was now painted black. Some emblems changed, and the car had inertial seat belts as standard. A special feature was the optionally available Avon safety tires, which enabled the car to be controlled at high speeds even in the event of a defect. 

The purchase price for a new car in 1975 was 12,587 British pounds.

The Bristol 411 Mk. 5 was the last Bristol model whose body was conceptually based on the Bristol 406, which is now 15 years old. It was replaced in autumn 1976 by the Bristol 603, which received a completely new, independent design.

• PERFORMANCE: 383 cu in
  max power (SAE): 335 hp at 5,200 rpm
  max torque (SAE): 425 1b ft, 58.6 kg m at 3,400 rpm
  max engine rpm: 5,500
  specific power: 53 hp/l
  max speeds: 50 mph, 80 km/h in 1st gear: 90 mph, 145 km/h in 2nd gear; 140 mph, 225 km/h in 3rd gear
  power-weight ratio: 11 lb/hp, 5 kg/hp
  carrying capacity: 904 lb. 410 kg
  acceleration: 0-50 (0-80 km/h) 6 sec;
  speed in direct drive at 1,000 rpm: 26.4 mph, 42.5 km/h;
  fuel consumption: 18 m/ imp gal, 15 m/ US gal, 15.7 1 x 100 km.
• PERFORMANCE: 400 cu in
  max power (SAE): 335 hp at 5,200 rpm
  max torque (SAE): 418 1b ft, 57.7 kg m at 3,400 rpm;
  max engine rpm: 5,500: 51 hp/l
  max speeds: (l) 50 mph, 80 km/h; (Il) 90 mph, 145 km/h; (Ill) 140 mph, 225 km/h
  power-weight ratio: 11 lb/hp, 5 kg/hp
  carrying capacity: 904 1b, 410 kg
  acceleration: 0-50 mph (0-80 km/h) 6 sec; speed in direct drive at 1,000 rpm: 26 mph, 41.8 km/h
  fuel consumption: 16 m/imp gal, 13.3 m/US gal, 17.7 1 x 100 km.

Bristol Cars offers a modernised version of the Bristol 411, the Series 6. The factory Bristol 411 Series 6 model occupies a special position. The automobiles of this generation are not new cars, but extensively restored vehicles from earlier series. The first Bristol 411 Series 6 was completed in 2008. Other Bristol eight-cylinder models were later converted in this way. The vehicles were delivered with a new vehicle guarantee.

As part of the restoration, the customers' used vehicles are completely dismantled and rebuilt using numerous new parts. The chassis of the donor vehicle is also the basis of the newly built vehicle. While the body design remains unchanged, the technical components are largely replaced. The vehicles receive the drive and chassis technology of the current Bristol Blenheim 3, so that the driving performance, the driving behaviour and the exhaust gas values ​​are significantly improved. The vehicles are equipped with the current 5.9 Liter eight-cylinder engine; depending on the customer's wishes, the standard version or the heavily machined version from the Blenheim 3S can be used, which, according to the factory, has an output of up to 400 hp. The computer-controlled four-speed automatic of the Blenheim is also carried over. Finally, the vehicles will have a modern audio system, a satellite navigation system and an iPod connection.