I just got a 1977 and can’t figure out what these two levers are for. They aren’t mentioned in the owner’s manual, either.

They are horizontal levers on each on each side of the car on the kick panels just forward of the doors. They move through what appear to be vents of some sort... perforations in the panels.

The owner’s manual mentions the vent ***** next to the ball-type vents in the dash, but are these somehow related to ventilation as well?

This a photo of the driver’s side.

 

 

Wow, that's different. My guess is your car is a non-AC car?
On my '71 you open these vents by a lever on each side of the center console shift plate. I don't think they were present on AC cars, could be wrong.

 

 

That's pretty interesting, and confusing too. I have a '77 with AC, no levers on the kick panels. The perforations make the panels look like they were intended to have speakers behind them. I know '77s didn't come with kick panel speakers, always thought that was just a production quirk but it's even stranger that there are slots and levers through panels with speaker perforations. I wonder what the history is behind that production oddity.

 

Those ***** look to be "owner add-ons", IMO. Perhaps the controls on the heater head no longer work. I never owned a '77, but those don't look to be 'factory' to me.

 

Sure doesn't look like factory did it? The cuts in the kick panel look manmade and very inconvenient place to put a **** to control

 

My first impression was that 'Bubba' did a very nice job. T

 

My Non-AC 77 has these same vents, and they operate a vent door that is behind the vent openings on the forward side of the kick panels....you can see the vent opening in the picture. Its purely a butterfly door that is mechanically opened and closed by the ball lever. I know, I put new rubber seals on the door.

That air comes from the wiper bay, down both sides in front of the A pillar and provides outside air to your feet area. At 55 mph, there is quite a bit of air movement. This supplements the ball vent air mounted in lower corners of the panels.

I will also add that this is one reason it is important that the hood seal that runs across the front of the wiper bay is installed....otherwise you get engine heated air channeling into the wiper bay, and then directly through this vent, when open, into your feet.

 

My orange 77 is also L48, 4-speed, no-AC, crank windows, factory alloys, but mine was originally light brown leather....I converted the whole interior to black.

By 77, Chevrolet had done away with lots of silly doo-dads, and had improved and simplified the car in many ways. It was the first year of sport mirrors, which in my opinion, finally put a mirror on a Corvette that matched the styling of the body....rather than a Model T mirror. The steering wheel was also finally a respectable sports car steering wheel rather than the spindly predecessor. I could go on, but some people take offense and not the subject of the thread......maybe I will start another thread making these points??

 

Mines a 77 without A/C and the vents and operating **** in mine are the same as yours, from the factory that way.....no Bubba involved

 

Wow. GM cost-reduction 'special'. I guess, if they work, they get the job done.

In the mid-70's, over 90% of Corvettes ordered A/C. Maybe GM opted to make the A/C car the 'standard' build model and had a "work-around" design for the non-A/C cars. In 1980, A/C became standard fare.

 

All non AC C3s had manually operated fresh air vents. These were on the console through 76 and used Bowden cables for operation. For the new console design for 77, they were moved to the kick panels and the cables were eliminated.

 

My 78 non ac, crank window car has the same operation. Pretty simple operation, forward=closed vent.

 

There was definitely no "Bubba" here, there is a paragraph about these levers in the owner's manual, albeit just a brief mention.

It seems this is a remnant of the old Astro Ventilation system. Earlier C3s also had vents on the rear deck just behind the rear window which had a vacuum operated vent flap... it seems the idea is that air would enter from these cowl-fed vents in front and flow through the cabin to be exhausted out the rear... I presume there was a lot of vacuum created by the airflow over the rear deck when the car was at speed.

Those rear vents were eliminated at some point, it doesn't take a genius to figure that they must have allowed water to enter (they faced upwards and were on the flat surface of the rear deck) and must have added a lot of complexity for the vacuum system, water drainage, etc. The increased use of air conditioning likely made them an anachronism, anyway.

I'm more surprised that Chevrolet would bother to still include these just for non-AC cars as late as 1977. I guess they hadn't caught on to the "less build complexity/less manufacturing cost" ideas the Japanese were perfecting at the time.

When I first looked at the car I didn't even notice them. I just assumed that the perforations in the kick panels were for speakers, even though my car is/was originally equipped with just an AM/FM mono radio.

I look forward to getting the car up to speed soon to see how effective these vents are. Mine still appear to open and close smoothly, I doubt they were ever used much over the past 40 years.

It's fun learning about all of these little quirks about the Corvette. It's easy to forget that the design for the C3 was done in the mid 1960s and it actually shared many components with the C2 which was designed nearly a decade earlier. All of the vacuum operated doors, flaps, lights, etc. in the early C3s must have been incredibly complex to build and keep operating correctly, but it also made it quite a showpiece for Chevrolet.

 

Another interesting difference on my non-AC car. I hadn't really noticed before, but now that I look at photos of other '77s, I see that there is a panel that says "Corvette" covering what would have been the top center vents above the central gauges on a car with air conditioning. Seems odd, one would think that these vents could still have been used for fresh air flow but I guess not.

On cars with A/C, does the cold air only come out from these top center vents?

 

No. Cooled air also comes through the vent ***** in the dash.

 

Odd. So why no top center vents on the non-a/c cars?

 

I believe 68 and 69 actually had kick panel speakers.

 

Non AC cars did not get the center vents. They got the CORVETTE block off plate. Depending on model year, there may be a small duct above the fuel and temp gauges and under the CORVETTE which provides a tad of fresh air.



Offhand, I can't recall whether the 77s got the duct.

FWIW: Of all the available options, factory air (C60) required the most changes to the base car. The C60 option section in the AIMs is always several pages long outlining everything which was needed to get the system installed.