With the 1966 Corvette arriving after General Motors recent, overwhelming success with the 427 Sting Ray, there was no question that the newest Corvette model would continue to feature big-block engines.
This turnabout in events was rather interesting, especially given GM management’s earlier decree that no car line smaller than a full-size model would carry an engine larger than 400 cubic inches. Perhaps fortunately for Corvette, it was Carroll Shelby’s two-seat Cobra, which featured its own 427 cubic inch V8 engine that prompted the change of opinion.
Chevrolet now felt it would also need a 427 cubic inch engine, and it materialized for the 1966 model year.
Although it was effectively a 396 cubic inch engine with a larger 4.25-inch bore, the new 427 big-block engine came in two forms: the relatively mild L36, which featured a hydraulic-cam and produced 390 horsepower on 10.25:1 compression, and the truly awesome L72, a 425 horsepower engine with 11:1 compression, larger intake valves, a bigger Holley four-barrel carburetor on an aluminum manifold, mechanical lifters, and four-hole (instead of two-hole) main bearing caps.
Though it had no more horsepower than the previously developed 396 cubic inch engine, the 427 did pack quite a bit more torque-460lbs/ft instead of 415.
Given the fact that, especially in the Sixties, engine outputs were sometimes deliberately understated, it is not unreasonable to assume that the output of these two engines was closer to 420 and 450 horsepower respectively.
There were limitations to ordering the big block 427 cubic inch engine. First, it had to be ordered in combination with Positraction and the close-ratio Muncie four-speed transmission. It also required that the Corvette was equipped with an upgraded suspension, similar to the setup on the 396 package. Lastly, it required stouter, shot-peened halfshafts and U-joints, as well as a higher-capacity radiator and sump.
DID YOU KNOW: The 427 cubic-inch engines were introduced in the 1966 model. Corvettes equipped with this type of engine received a special bubble hood first seen on the 1965 Corvettes equipped with the 396 cubic inch engine. Although initially listed as a 450hp engine, the solid lifter 427ci engine’s rating was later reduced to 425hp shortly after its introduction for reasons unknown. Similarly, the 390 horsepower engine was initially rated at 400 horsepower. When the official ratings were reduced, the decision to make this change was purely administrative and was not the result of any changes made to the engines.
The introduction of the big-block V-8 engine captured the imagination of Corvette consumers the world over, and in no time at all, the demand for big-blocks far surpassed those of the conventional 327 small block Chevy engine.
As a result, the small-block engine options were reduced from five to two for the 1966 model year, with only the 300-horsepower (L75) and 350-horsepower (L79) versions remaining available to prospective consumers. Even amongst the earlier small-block options that had been available on earlier Corvettes, these two engines were arguably the best all-around engines.
Additionally, both could be paired with the Powerglide automatic, the standard three-speed manual, or either of the optional four-speed manual transmissions.
With the exception of the dramatic new lineup of engine choices, there was little else that was deemed “new” for the 1966 model year.
There were minor modifications made to the Corvette’s appearance. For one, the Sting Ray’s front end was mildly altered with the introduction of an “eggcrate” grille insert which replaced the previously installed horizontal bars.
Restyled wheel covers were introduced along with an all new rocker trim. Also, the coupe lost its roof-mounted extractor vents, which had proven to be inefficient on earlier model years.
Lastly, less notable upgrades like the addition of “Corvette Sting Ray” scripts to the hood and the introduction of standard backup lights were introduced.
Likewise, the interior went largely unaltered from 1965. The interior electric ventilation system was dropped (in conjunction with the aforementioned exterior vents), extra pleats were added to the Sting Ray’s bucket seats, chrome door pull handles were introduced, headrests were made optional, and a vinyl-covered foam headliner replaced the previously used fiberboard.
Given that these were amongst the only notable changes from 1965 to 1966, there was a good deal of reasonable speculation that an all-new Corvette was slated for 1967
Still, the lack of changes for the 1966 model year did not hurt the Corvette’s popularity with consumers. In fact, 1966 would prove to be another record-breaking year in Corvette sales, with volume rising to 27,720 units sold – an increase of more than 4,200 units over 1965’s sales of 23,562 units.
Consumers found that the new Corvette, especially one equipped with the 427 big-block, had all the refinement it needed. The 427 Sting Ray was an astonishingly fast car, with 0-60 times of just 4.8 seconds, 0-100 mph times of 11.2 seconds, and a top speed of 140 miles per hour (when properly equipped with the short 4.11:1 gearing.) Even in cars equipped with the somewhat less sensational 3.36:1 ratio, the Corvette was still able to run 0-60 times of 5.4 seconds with a standing quarter of 12.8 seconds at 112 miles per hour (source Car and Driver).
Impressive as those numbers were, the intent of the 427 cubic inch engine had been to meet the Shelby Cobra head-on and give it some staunch competition. However, even despite the staggering horsepower and the impressive performance numbers, the fact remained that the Corvette was a half a ton heavier than the Shelby Cobra so, even with the same horsepower rating, it was considered less than a threat. Still, the Corvette did not go home empty handed. The Corvette still took a number of victories in endurance racing including Penske’s team’s 12th place overall in the GT class.
Two-door convertible/coupe, front engine, rear wheel drive
St. Louis, Missouri
Fiberglass Reinforced Plastic (FRP or “fiberglass”) body, all welded, full length, ladder construction frame with 5 cross-members. Front section flat;rear section contoured over rear axle. Side-rails and intermediate cross members box construction. Rear crossmember “C” shaped; front crossmember concave for engine clearance.
VEHICLE NUMBERS (VIN):
194376S100001 – 194376S127720
HD: 327 CUBIC INCH, 350 HP, MANUAL TRANS, AIR INJECTION REACTOR
HE: 327 CUBIC INCH, 300 HP, MANUAL TRANS
HT: 327 CUBIC INCH, 350 HP, MANUAL TRANS
HH: 327 CUBIC INCH, 300 HP, MANUAL TRANS, AIR INJECTION REACTOR
HO: 327 CUBIC INCH, 300 HP, POWERGLIDE AUTO TRANS
HP: 327 CUBIC INCH, 350 HP, MANUAL TRANS, POWER STEERING, AIR CON
HR: 327 CUBIC INCH, 300 HP, POWERGLIDE AUTO TRANS, AIR INJECTION REACTOR
IK: 427 CUBIC INCH, 425 HP, MANUAL TRANS
IL: 427 CUBIC INCH, 390 HP, MANUAL TRANS
IM: 427 CUBIC INCH, 390 HP, MANUAL TRANS, AIR INJECTION REACTOR
IP: 427 CUBIC INCH, 425 HP, MANUAL TRANS
IQ: 427 CUBIC INCH, 390 HP, POWERGLIDE AUTO TRANS
IR: 427 CUBIC INCH, 390 HP, POWERGLIDE AUTO TRANS, AIR INJECTION REACTOR
ENGINE BLOCK NUMBER:
3858174, 327 CUBIC INCH
3892657, 327 CUBIC INCH
3855961, 427 CUBIC INCH
3869942, 427 CUBIC INCH
3904351, 427 CUBIC INCH
Type and Description: Independent coil spring spherical joint suspension with concentric springs and shock absorbers between upper and lower control arms. Built-in anti-dive control and rubber-bushed link-type stabilizer bar. Quiet, low-friction non-metallic spherical joint liners. Spherical joints protected by special positive-sealing formed-rubber boots.
Front Coil Springs
Make & Type
Right-hand Helix Variable rate
AISI A-5160, heat-treated
Spring Rate (lb. per in.)
195 lb. per in.
Rate at Wheel (lb. per in.)
80 lb. per in.
1340 lb. @ 8.56 in.
Front Shock Absorbers
Make & Type
Direct, double-acting, hydraulic; freon filled envelope in reservoir
Front Stabilizer Bar
Hot rolled steel
.750 with 327ci engine, .875 with 427ci engine
Suspension – Back
Type and Description: Independent rear suspension with frame-mounted differential unit, double universal jointed tubular axles, and transverse multi-leaf spring. Differential carrier is mounted to frame by rubber-isolated with hardened and tempered chrome carbon steel leaves bolts solidly to differential carrier and attaches to radius arms with rubber-isolated floating rods. Suspension design permits to function as springing member only. Lateral and longitudinal forces imposed by braking, acceleration, and cornering are absorbed by frame-mounted fixed differential and suspension control arms.
Rear Leaf Springs
Number of Leaves
Chrome carbon steel
Length, width, height
46.36 x 2.25 x 2.121
Rear Shock Absorbers:
Direct, double-acting, hydraulic; freon filled envelope in reservoir
Caliper Disk – 4 Wheel Hydraulic
Drum diameter, front (in.):
Drum diameter, rear (in.):
Swept Drum Area Effective area:
Wheels & Tires
Wheels & Tires Specs
Short spoke spider, steel
Ribbed integral casting, aluminum, quick take-off
15″ x 5.5K
15″ x 6L
7.75 x 15 — 4 PR. 4-Ply Tubeless Rayon
7.75 x 15 — 4 PR. 4-Ply Whitewall Rayon
7.75 x 15 — 4 PR. 4-Ply Goldwall Nylon
Semi-reversible, recirculating ball and nut steering gear with three-inch axial column adjustment; two-location steering arm-tie rod connection for street and fast ratio. Telescoping shaft steering available optionally.
Wheel Diameter (in.)
Turns, Stop to Stop
39.9 ft. (outside front), 41.6 ft. (outside front)
Vehicle Assembly Location. S – St. Louis, Missouri
1XXXXX (Seventh thru Twelfth Digits)
Plant Sequence Numbers.
The last six digits begin at 100001 and run thru 127720, accounting for all 27,720 Corvette Coupes/Convertibles built in 1966. Each Vehicle Identification Number (VIN) is unique to an individual car. For all 1966 Corvettes, the location of the Vehicle Identification Number (VIN), body style, body number trim and paint combination can be found on the instrument panel brace under the glove box.
1966 Corvette Factory Options
Base Corvette Sport Coupe
Base Corvette Convertible
Genuine Leather Seats, Black
Genuine Leather Seats, Red
Genuine Leather Seats, Bright Blue
Genuine Leather Seats, Dark Blue
Genuine Leather Seats, Saddle
Genuine Leather Seats, Silver/Black
Genuine Leather Seats, Green
Genuine Leather Seats, White/Blue
Soft Ray Tinted Glass, All Windows
Soft Ray Tinted Glass, Windshield
Auxillary Hardtop (for convertibles)
Heater and Defroster Deletion (credit)
Special Front and rear Suspension
Positraction Rear Axle, all ratios
Special Heavy Duty Brakes
Air Injection Reactor
Transistor Ignition System
427ci, 390hp Engine
427ci, 425hp Engine
327ci, 350hp Engine
4-Speed Manual Transmission
4-Speed Manual Transmission, Close Ratio
4-Speed Manual Trans., Close Ratio, Heavy Duty
Powerglide Automatic Transmission
36 Gallon Fuel Tank (for coupe)
Off Road Exhaust System
Side Mount Exhaust System
Teakwood Steering Wheel
Telescopic Steering Column
Cast Aluminum Knock-Off Wheels (5)
Whitewall Tires, 7.75 x 15 (rayon cord)
Goldwall Tires, 7.75 x 15 (nylon cord)
Traffic Hazard Warning Switch
Base Corvette Coupe (19437)
The base price of the 1966 Chevrolet Corvette Coupe without any optional equipment.
A 327 cubic inch, 300 horsepower engine, a 3-speed manual transmission, and a vinyl interior were included in the base price.
Base Corvette Convertible (19467)
The base price of the 1966 Corvette Convertible without any optional equipment.
A 327 cubic inch, 300 horsepower engine, a 3-speed manual transmission, a vinyl interior, and a soft top were included in the base price.
Genuine Leather Seats
Optional leather upgrade to replace the standard vinyl seats on the 1966 Corvette.
Soft Ray Tinted Glass, All Windows (A01)
Window tint applied to the upper portion of the windshield and all other windows.
Originally manufactured by Libby-Owens-Ford (LOF) the glass plate was specially etched with the LOF logo and date code.
It also included the words “Soft-Ray” or “Soft-Ray Tinted” in the etching.
Soft-ray is factory manufactured window tint.
Soft-ray tint is a bluish-green in color.
Soft Ray Tinted Glass, Windshield (A02)
Factory window tint applied to the windshield only.
Originally manufactured by Libby-Owens-Ford (LOF) the glass plate was specially etched with the LOF logo and date code. It also included the words “Soft-Ray” or “Soft-Ray Tinted” in the etching.
Soft-ray tint is a bluish-green in color.
Power Windows (A31)
Factory installed power driver and passenger windows.
A head restraint attached to the top of the seat for both safety and comfort.
Shoulder Belts (A85)
An addition to the standard lap safety belt that crosses over the shoulder for added safety.
Auxillary Hardtop (for convertibles) (C07)
An optional hard-top that could be installed in lieu of the convertible top.
Of the 8,463 Corvette convertibles sold that included this option, 1,303 Corvettes had the removable hard top installed in place of the factory installed soft top.
Heater and Defroster Deletion (credit) (C48)
Deletion of the factory installed heater and defroster.
Corvettes that included this option were generally built for racing and rally driving.
Air Conditioning (C60)
Factory installed air-conditioning.
Special Front and Rear Suspension (F41)
An optional suspension with upgraded springs, shock absorbers, and stabilizer bar.
Heavy-duty stabilizer bar
Heavy-duty front and rear springs and shock absorbers
Positraction Rear Axle, all ratios (G81)
Includes 3.08, 3.36, 3.55, 3.70, and 4.11 axle ratios.
Power Brakes (J50)
Vacuum power assisted brakes; includes dual circuit master cylinder.
Air Injection Reactor (K19)
Used to mix fresh air with hot exhaust gases to react with unburned gasoline to reduce emissions.
Approved by the state of California and exclusive to California vehicle registration only.
Not required with 425hp Engine.
Transistor Ignition System (K66)
Deltronic ignition system by Delco -Remy
Will yield higher spark plug voltage.
Will operate at extremely high speeds without losing ignition performance.
Is essentially maintenance free.
427ci, 390hp Engine (L36)
Alternate engine with improved 390 horsepower output.
427ci, 425hp Engine (L72)
Alternate engine with improved 425 horsepower output.
327ci, 350hp Engine (L79)
Alternate engine with improved 365 horsepower output.
4-Speed Manual Transmission (M20)
4-Speed Manual Transmission, Close Ratio (M21)
4-Speed Manual Trans, Close Ratio, Heavy Duty (M22)
Powerglide Automatic Transmission (M35)
Of the 2,401 Corvettes that were ordered with this option, the quantity was split with 2,381 Corvettes that came equipped with a 300 horsepower engine, and 20 with a 390 horsepower engine.
36 Gallon Fuel Tank (for coupe) (N03)
Larger, optional, 36 gallon fuel tank.
The 36 gallon tank was specifically intended for endurance racing.
Off Road Exhaust System (N11)
Recessed exhaust system designed to eliminate rubbing in varying road conditions.
The mufflers include double-wall construction with a special, raised area on the outer shell that conceals the inner seam crease.
Originally made of carbon-steel components.
Side Mount Exhaust System (N14)
Teakwood Steering Wheel (N32)
An optional steering wheel made of wood.
Telescopic Steering Column (N36)
Power Steering (N40)
Hydraulically assisted power steering.
Cast Aluminum Knock-Off Wheels (5) (P48)
Cast aluminum wheels equipped with “knockoff” (central wing nut) hubs that could be unscrewed by striking a wing of the nut with a mallet or “knockoff hammer”.
Whitewall Tires, 7.75 x 15 (rayon cord) (P92)
Goldwall Tires, 7.75 x 15 (nylon cord) (T01)
AM-FM Radio (U69)
An optional radio that gave consumers the option of both AM and FM radio frequency bands.
Traffic Hazard Warning Switch (V74)
1966 Corvette Recalls
Make: CHEVROLET Model: CORVETTE Model Year: 1966 Manufacturer: Cardone Industries, Inc. MFR’s Report Date: May 07, 2003 NHTSA Campaign Id Number: 03e032000 NHTSA Action Number: N/a Component: Service Brakes, Air: disc: caliper
Remanufactured Rear Brake Calipers, Part Nos. 18-7019, 18-7020, 16-7019, And 16-7020, Manufactured From February 1, 2002, To April, 25, 2003., And For Use On 1965 Thru 1982 Chevrolet Corvettes. The Subject Brake Calipers Were Manufactured Using Improperly Manufactured Piston Seals. These Seals Are Intended To Prevent Fluid Leakage Between The Caliper Housing And The Pistons. These Brake Calipers Are For Use Only On 1965 Thru 1982 Chevrolet Corvette Vehicles. This Recall Does Not Involve General Motors Corporation Or Any Of Its Products.
Under These Conditions, The Vehicle Operator May Not Be Able To Stop The Car, Possibly Resulting In A Vehicle Crash.
Cardone Will Notify Its Customers And All Unsold Inventory Will Be Repurchased And Will Provide A Full Refund To Customers. Owner Notification Is Expected To Begin During May 2003. Owners Who Take Their Vehicles To An Authorized Dealer On An Agreed Upon Service Date And Do Not Receive The Free Remedy Within A Reasonable Time Should Contact Cardone At 215-912-3000.
Also, Customers Can Contact The National Highway Traffic Safety Administration’s Auto Safety Hotline At 1-888-dash-2-dot (1-888-327-4236).
1966 Corvette Service Bulletins
1966 Corvette Common Issues
The following list of common issues is intended for individual reference only, and may not reflect the specific issues of every 1966 Corvette. While the intent of this page is to identify the common issues pertaining to the 1966 Corvette, it is not an all-inclusive list and should be used for reference only.
1966 Corvette Mechanical Issues
HEADLIGHT MOTOR ASSEMBLY
There are two common problems that often occur with the headlight motor assembly. First, it is not uncommon for only one of the headlight motor assemblies to open. Second, the headlight assemblies may open in tandem, but they open very slowly, making them virtually non-functional. The cause of these issues are varied, but often occur because of either the failure of the headlight motor drive assemblies, or the misalignment of the transmission mechanism that physically rotates the headlight. In some instances, the headlight switch can also be the cause, and it is recommended that the switch be replaced in addition to other headlight motor mechanical repairs. There are a number of aftermarket parts manufacturers that produce OEM spec headlight motor and transmission assemblies.
(See also “Exterior Issues” (below) for additional headlight related issues)
TAIL LIGHT/REAR TURN SIGNAL
All C2 Corvettes (1963-1967) have a persistent problem with poor electrical grounds on their tail lights. The original design used speed nuts to hold the ground wire on, and these nuts do not remain tight.
The rear suspension utilized a transverse-mounted leaf spring with nine leaves, axle half shafts with U-joints, control arms and tubular shocks. Over time, this setup is known to fail due to normal fatigue. The rear suspension should be checked regularly, especially on vehicles with aging suspension.
WASHER PUMP ASSEMBLY
Mechanical failure of the washer pump assembly is a common issue on both C2 and C3 Corvettes. The washer pump will not disperse washer fluid even though all of the hoses are inspected and properly connected, the washer fluid reservoir is full, and the washer nozzles are lear of debris. When this occurs, it is often the result of a bad washer pump nozzle valve. During normal (proper) operating conditions, the valve receives the washer fluid solution from the reservoir, and then it is forced (via the pump) to spray out through the washer fluid nozzles. The washer pump nozzle valve contains a small rubber diaphragm that can dry out and become brittle with age. It is generally the failure of this internal diaphragm which causes the mechanical failure within the valve itself.
1966 Corvette Electrical Issues
Resistive spark plugs were used in the second-generation Corvettes although they caused degraded engine performance. However, they were used in conjunction with shielded plug wiring to cut down on radio static. Because the fiberglass body of a Corvette did not provide electrical shielding like a conventional steel body would, radio static was a genuine problem for all of the second-generation Corvettes.
1966 Corvette Exterior Issues
Given that the C2 electric headlight assemblies are exposed to weather, they are commonly known to have problems.
The door seals tend to leak fairly regularly, especially the top portion of the door seal.
The chassis is one of the C2’s major sources of trouble. The main frame rails are prone to rusting, as is the rear kick-up behind the cabin and in front of the rear wheel. Other areas that are prone to serious fatigue from rusting include: the rear trailing/control arms, the inner “bird cage” metal substructure that supports the fiberglass body panels, the inner door frames, the door pillars, and the cowl area at the base of the windshield.
Radiator supports and the gas tank are prone to corrosion.
1966 Corvette Interior Issues
As the result of age or excessive wear, many 1963-1967 Corvettes are known to have sagging floorboards. This problem can sometimes be addressed by carefully raising the sagging floorboard using a floor jack & wooden blocks and then installing two rubber spacers on either side of the tunnel between the crossmember and floorboard where the floorboard is sagging (typically just outboard of the exhaust pipe holes).
TURN SIGNAL CAM FAILURE
Within the steering column, there is a turn signal cam assembly that regulates the control of the turn signal lever. As the cam ages, it can stop operating. When this happens, the turn signal level will not return to its neutral position and the turn signal will continue signaling, even after the completion of the intended turn of the steering wheel. While replacement of this cam assembly generally takes a couple hours to complete, it is not a difficult repair to make, though it will require the removal of the steering wheel to access the cam.
1966 Corvette Maintenance Schedule
The time or mileage intervals indicated on this website are intended as a guide for establishing regular maintenance and lubrication periods. Sustained heavy duty or high speed driving, or driving under adverse conditions may require more frequent servicing.
Additional Maintenance and Lubrication
In addition to the items listed above, it is also recommended that the following items are inspected every 300 miles or 2 weeks, whichever comes first:
Check Tire Pressure
Check Battery Water Level
Check Oil Level In Engine
Remove air cleaner and block throttle and choke in wide open position. Hook up starter remote control cable and insert compression gauge firmly in spark plug port. Whenever the engine is cranked remotely at the starter, with a jumper cable or other means, the distributor primary lead must be disconnected from the negative post on the coil and the ignition switch must be in the “ON” position. Failure to do this will result in a damaged grounding circuit in the ignition switch.
Crank engine through at least four compression strokes to obtain highest possible reading. Check and record compression of each cylinder. If one or more cylinders reads low or uneven, inject about a tablespoon of engine oil on top of pistons in low reading cylinders (through spark plug port.) Crank engine several times and recheck compression. If compression comes up but does not necessarily reach normal, rings are worn. If compression does not improve, valves are burnt, sticking or not sealing properly. If two adjacent cylinders indicate low compression, the cause may be a head gasket leak between the cylinders. Engine coolant and/or oil in cylinders could result from this defect.
The adjustments described apply to all carburetors used, except as noted. All adjustments are made with the engine at normal operating temperature.
Idle Speed and Mixture(1966-1970)
Remove distributor vacuum line at distributor and plug hose. Start engine and set the throttle stop screw for recommended idle speed. The choke valve must be wide open and the fast idle inoperative. Adjust one idle mixture screw at a time for smoothest, fastest idle speed. On A.I.R. cars, turn one adjusting screw at a time until engine speed drops approximately 30 rpm and starts to roll (lean mixture), then turn screw out exactly 1/4 turn for final setting. Readjust throttle stop screw for recommended idle speed. Basic setting for idle mixture screws is 2 turns open from fully closed for 1966-68, 3 turns for 1969, 1 turn for Holley 2300, Air condition to be ON, except Mark IV and all 1972.
When adjusting the idle speed be sure that the idle compensator is closed. Close it manually if necessary. After idle speed is adjusted, check by pressing down on the compensator. If speed drops, readjust idle speed. NOTE: Idle speed adjustments on cars with automatic transmissions must be made with transmission in Drive and idle stator switch, if so equipped, closed. Be sure parking brake is on.
Idle Speed and Mixture – Holley 2300
All adjustments are same as previously described except as follows: On models equipped with idle stop solenoid, adjust idle stop solenoid screw to give 1000 rpm, then adjust idle mixture adjusting screw to specified rpm. Turn idle mixture screw in (leaner mixture) until engine speed drops 20 rpm, then turn out 1/4 turn. Disconnect lead at idle stop solenoid (throttle level will rest against regular stopscrew.) Adjust this stopscrew for idle speed of 500 rpm. Do not change setting of idle stop solenoid stopscrew or idle mixture screw.
Fast Idle (1966-1976)
With the transmission in neutral, position the cam follower on the high step (2nd step, 1971-1972) of the fast idle cam. Adjust fast idle screw of Rochester carburetors to obtain recommended fast idle speed. Bend fast idle lever on Holleys. On 1970-72 models, disconnect transmission controlled spark solenoid.
With slow idle speed correctly adjusted, fully open choke and make sure fast idle cam follower is off steps of cam. With dashpot fully compressed, adjust for 1/16″ clearance between dashpot plunger and throttle lever.
Remove the air cleaner and check to see that choke valve and rod more freely. Disconnect choke rod at choke lever. Check choke adjustment by holding choke valve closed and position rod so that it contacts stop. If necessary, adjust rod length by bending rod at offset. Bend must be such that rod enters choke lever hole freely and squarely. Connect rod at choke lever and install air cleaner.
Air Injection Reactor (A.I.R.)
Description and Operation
The A.I.R. system is used to burn the unburned portion of the exhaust gases to reduce its hydrocarbon and carbon monoxide content. The system forces compressed air into the exhaust manifold where it mixes with the hot exhaust gases. The hot exhaust gases contain unburned particles that complete their combustion when the addition air is supplied.
The system consists of: An air pump, diverter valve, check valve(s), AIR pipe assemblies and connecting hoses and fittings. Carburetors and distributors for AIR engines are made to be used with the system and should not be replaced with components intended for use with engines that do not have the system.
The air pump is a two-vane pump which compresses fresh filtered air and injects it into the exhaust manifold. The pump consists of: a housing, centrifugal filter, set of vanes that rotate about the centerline of pump housing bore, the rotor, and the seals for the vanes. The centrifugal filter is replaced by first removing the drive belt and pump pulley; then pulling filter off with pliers. Care should be taken to prevent fragments from entering the air intake hole. NOTE: A new filter may squeal when first put into operation. Additionally, GREAT CARE should be taken in working on the compressor as the aluminum used is quite soft and thin. The air pump is operating satisfactorily when the air flow from it increases as engine speed increases.
The air hoses should be replaced only with hoses which are designed for AIR system use, as no other type hoses can withstand the high temperature.
Check and Adjust Dwell
Start engine then check ignition dwell. With engine running at idle, raise the adjustment screw window and insert an Allen wrench in the socket of the adjusting screw. Turn the adjusting screw as required until a dwell reading of thirty degrees is obtained. A two degree variation is allowable for wear. Close access cover fully to prevent the entry of dirt into the distributor. If a dwell meter is not available, turn adjusting screw clockwise until engine starts to misfire, then turn screw one-half turn in the opposite direction to complete adjustment.
Slowly accelerate engine to 1500 rpm and note dwell reading. Return engine to idle and note dwell reading. If dwell variation exceeds specifications, check for worn distributor shaft, worn distributor shaft bushing or loose breaker plate.
Remove distributor cap, clean cap and inspect for cracks, carbon tracks and burned or corroded terminals. Replace cap where necessary. Clean rotor and inspect for damage or deterioration. Replace rotor where necessary. Replace brittle, oil soaked or damaged spark plug wires. Install all wires to proper spark plug. Proper positioning of spark plug wires in supports is important to prevent cross-firing. Tighten all ignition system connections. Replace or repair any wires that are frayed, loose or damaged.
Disconnect the distributor spark advance hose and plug the vacuum source opening. Start engine and run at idle speed. Aim timing light at timing tab. The markings on the tabs are in two degree increments (the greatest number of markings on the “A” side of the “Q”). The “O” marking is TDC (Top Dead Center) and the BTDC settings fall on the “A” (advance) side of the “O”. Adjust the timing by loosening the distributor clamp and rotating the distributor body as required, then tighten the clamp, and recheck timing. Stop engine and remove timing light and reconnect the spark advance hose.
Inspect each plug individually for badly worn electrodes, glazed, broken or blistered porcelains and replace plugs where necessary. Clean serviceable spark plugs thoroughly, using an abrasive-type cleaner such as sand blast. File the center electrode flat. Inspect each spark plug for make and heat range. All plugs must be of the same make and number. Adjust spark plug gaps to .035 in. using a round feeler gauge. If available, test plugs with a spark plug tester. Inspect spark plug hole threads and clean before installing plugs. Install spark plugs with new gaskets and torque to specifications. Connect spark plug wiring.
Transistorized Distributor (H.E.I. System)
There are no moving parts in the ignition pulse amplifier, and the distributor shaft and bushings have permanent type lubrication, therefore no periodic maintenance is required for the magnetic pulse ignition system.
Distributor (Breaker Point System)
Check the distributor centrifugal advance mechanisms by turning the distributor rotor in a clockwise direction as far as possible, then releasing the rotor to see if the springs return it to its retarded position. If the rotor does not return readily, the distributor must be disassembled and the cause of the trouble corrected.
Check to see that the vacuum spark control operates freely by turning the movable breaker plate counter-clockwise to see if the spring returns to its retarded position. Any stiffness in the operation of the spark control will affect the ignition timing. Correct any interference or binding condition noted.
Examine distributor points and clean or replace if necessary. Contact points with an overall gray color and only slight roughness or pitting need not be replaced. Dirty points should be cleaned with a clean point file. Use only a few strokes of a clean, fine-cut contact file. The file should not be used on other metals and should not be allowed to become greasy or dirty. Never use emery cloth or sandpaper to clean contact points since particles will embed and cause arcing and rapid burning of points. Do not attempt to remove all roughness nor dress the point surfaces down smooth. Merely remove scale or dirt. Clean cam lobe with cleaning solvent, and rotate cam lubricator wick end (or one-hundred-eighty degrees as applicable). Replace points that are burned or badly pitted.
Where prematurely burned or badly pitted points are encountered, the ignition system and engine should be checked to determine the cause of trouble so that it can be eliminated. Unless the condition causing point burning or pitting is corrected, new points will provide no better service than the old points.
Check point alignment then adjust distributor contact point gap to .019″ (new points) or .016″ (used points). Breaker arm rubbing block must be on high point of lobe during adjustment. If contact points have been in service, they should be cleaned with a point file before adjusting with a feeler gauge.
Check distributor point spring tension (contact point pressure) with a spring gauge hooked to breaker lever at the contact and pull exerted at 90 degrees to the breaker lever. The points should be closed (cam follower between lobes) and the reading taken just as the points separate. Spring tension should be 19-23 ounces. If not within limits, replace. Excessive point pressure will cause excessive wear on the points, cam and rubber block. Weak point pressure permits bouncing or chattering, resulting in arcing and burning of the points and an ignition miss at high speed.
Install rotor and distributor cap. Press all wires firmly into cap towers.
Battery and Battery Cables
The top of the battery should be clean and the battery hold-down properly tightened. Particular care should be taken to see that the top of the battery is kept clean of acid film and dirt. When cleaning batteries, wash first with a dilute ammonia based or soda solution to neutralize any acid present and then flush off with clean water. Keep vent plugs tight so that the neutralizing solution does not enter the cell. The hold-down bolts should be kept tight enough to prevent the batter from shaking around in its holder, but they should onto be tightened to the point where the battery case will be placed under a severe strain.
To ensure good contact, the battery cables should be tight on the battery posts. Oil battery terminal felt washer. If the battery posts or cable terminals are corroded, the cables should be cleaned separately with a soda solution and wire brush. After cleaning and before installing clamps, apply a thin coating of a petrolatum to the posts and cable clamps to help slow corrosion.
If the battery has remain undercharged, check for loose or defective fan belt, defective alternator, high resistance in the charging circuit, oxidized regulator contact points, or a low voltage setting. If the battery has been using too much water, the voltage output is too high.
Inspect for deteriorated or plugged hoses. Inspect all hose connections. On engines with closed element air cleaners, inspect crankcase ventilation filter and replace if necessary. On engines with open element air cleaners, remove flame arrestor and wash in solvent then dry with compressed air.
Check the brake fluid regularly, for as the brake pads wear the level will drop rapidly. It should be replenished only with the recommended fluid. Check disc brake assemblies to see if they are wet; it would indicate a leaking cylinder.
Disc brakes do not need periodic adjustments; they are self adjusting. The pads should be replaced when the friction material gets down to 1/16″. This is when the groove in the center of the pad is gone. Check by removing wheel and looking directly into caliper.
Clutch Pedal Play
Check clutch action by holding pedal 1/2″ from floor and move shift lever between first and reverse several times, with engine running. If shift is not smooth adjust clutch. Free play with pedal released is approx. 1-1/4″ to 2″ and 2″ to 2-1/2″ for heavy duty.
At clutch lever near firewall remove clutch return spring. To decrease clutch pedal free play remove clutch pedal return spring and loosen lower nut on clutch pedal rod; take up play with upper nut. Continue until proper play is obtained, then securely tighten top nut and replace spring. To increase pedal play work nuts in opposite sequence.
Disconnect control linkage at carburetor throttle lever. Hold carburetor throttle lever in wide position. Pull control linkage to wide open position. (On vehicles equipped with automatic transmission, pull through detent.) Adjust control linkage to freely enter hole in carburetor throttle lever. Connect control linkage at throttle lever.
Throttle Linkage Adjustment (Powerglide)
Remove air cleaner, disconnect accelerator linkage at carburetor. Disconnect accelerator return and trans. road return springs. Pull upper rod forward until transmission is through detent. Open carburetor wide open, at which point ball stud must contact end of slot in upper rod. Adjust swivel on end of rod if necessary.
Pull detent switch driver to rear until hole in switch body lines up with hole in driver. Insert a 3/16″ pin through hole to depth of 1/8″, and loosen mounting bolts. Open throttle fully and move switch forward until lever touches accelerator lever. Tighten mounting bolt and remove pin.
EGR Valve Check
A rough idling engine may be caused by a malfunction of the valve. Check by pinching vacuum hose to carburetor with engine idling. If idling smooths out, the valve should be removed for cleaning or replacement if something appears to be broken.
The car should be standing on level ground and the oil level checked with the dipstick. Withdraw the dipstick, wipe it with a clean rag, replace and withdraw again. The mark made by the oil on the lower end of the dipstick will indicate the oil level. If necessary, oil should be added through the filler cap. Never let the oil level fall so low that it does not show at all on the dipstick. If in doubt, it is better to have a bit too much oil than too little. Never mix oils of different brands, the additives may not be compatible.
Engine Oil Drain and Replacement
Place a pan under the oil pan drain plug and remove plug. Be sure pan is of a large enough capacity to hold the oil. Move pan under filter and remove filter by turning if counterclockwise. Clean gasket surface of cylinder block. Coat gasket of new filter with engine oil. Thread filter into adapter. Tighten securely by hand. Do not overtighten filter. Remove drop pan.
Remove drain pan. Inspect oil pan drain plug gasket and replace if broken, cracked, or distorted. Install drain plug and tighten. Fill crankcase to required level with recommended oil. Operate engine at fast idle and check for oil leakage.
When changing oil filter, add one additional quart.
Check fluid level with engine idling, transmission in neutral and engine at normal operating temperature. Add fluid as needed to bring level to mark. Do not overfill.
Every 12,000 miles or sooner, depending on service, remove fluid from sump and add new fluid. Operate transmission and check fluid level. Every 24,000 miles the transmission sump strainer of the Turbo Hydra-Matic transmission should be replaced.
Raise car on lift, clean dirt and grease from area around the filler plug. Plug is located on side of transmission case. Remove plug and place finger tip inside hole. The oil should be just about level with the bottom edge of the hole. Add oil as needed, using a plastic syringe.
Change cam lubricator end for end at 12,000 mile intervals. Replace at 24,000 mile intervals.
With the car standing level, clean dirt and grease from area around filler plug. Remove plug and place finger tip inside hole. The oil should be just about level with the bottom edge of the hole. Add oil, with a plastic syringe, as needed.
1966 Corvette Dealers Sales Brochure
Download this 1966 Corvette Dealers Sales Brochure for a quick look at the features of the car.
Source Material: 1.) The Pocket Book of the Corvette: The Definitive Guide to the All American Sports Car – Copyright 2003, Barnes & Noble 2.) CORVETTE: Sports Car Superstar – Copyright 2005, PIL – Publications International, Ltd. 3.) Corvette Black Book – Copyright 2009, Michael Bruce Associates, Inc. 4.) The Complete Book of Corvette – Every Model Since 1963 – Copyright 2006, MBI Publishing