I have a couple of questions for you 68 owners.
I was looking at a couple of 68's this weekend at our local cruise in.
Question 1) Was the lip at the top of the firewall/cowl area painted black with the engine compartment like the 69 or left body color?
This would be the area not seen when the hood is down.
Qustion 2) Was the inner edge of the doors painted black between the door panels and the weatherstrip? The front area near the hinge access covers.
Question 3) On both of the convertibles I was looking at, the Astro Ventilation "doors" inside the car are not there like on the 69. They only had the foam flaps behind a plate, but no door and vacuum can controller. Both are non air cars. Were there no doors on the 68's? Found the answer to this one in a link to an old thread.
TIA all.

 

Hi 69,
Yes, the lip/gutter that separates the engine compartment from the wiper well was blacked out with the compartment and wiper well. The transitions from black to body color on the rest of the surround's gutter was done with a 'mask' so it wasn't precise or consistent.
The area around the upper door hinge on the door that's visible with the door open was painted black regardless of the interior's color.
I'm under the impression that from the start of production in 68 all cars without a/c had the Astro Ventilation doors, hardware, and vacuum actuator.
Regards,
Alan

 

Thanks Alan.
It is my understanding now that the "doors" did not appear till 69. Vents and flaps only on 68.
Inquring minds want to know.

 

My Jan build 68 has the cable controlled flaps on the sides of the interior compartment but no doors behind the chrome "*****" on the dash(as shown in the AIM) and no vacuum controlled door in the rear.

 

Same here.....maybe GM ran out of vacuum actuators/etc. the same day that they built our two cars

 

The 6t8 of mine has no rear frame gussets that the laters have, and the lower seat releases. So I suspect it's an early one. It has a lever and flap in the plastic that supports the chrome ***** [almost impossible to access]. Checked a later 68 and they aren't there, but mine was wrecked and has a lot of 69 parts on it. The 69s had the chrome vent lever coming through the dash pads, so I suspect that mine is correct to the year, just haven't seen any others like it. The console calbes control the vents by your feet and no rear actuator. T

 

Thanks all. I was just looking over a car for someone that just purchased it, and It was supposed to be quite original. I found the lack of black-out paint on the doors and the top of the firewall to be a bit telling as to its originality.
It still has a lot going for it though. It even has the strapping tape on the vacuum filter and valve.

 

Hi,
We've started talking about 2 very different things here concerning c69's question #3.
This question has nothing to do with the round chrome dash outlets or the kick panel vents. The a/c cars didn't have the fresh air levers on the console shifter plate that control the kick panel vents.
The question was about the astro ventilation grills, plenums, and the vacuum controlled doors that are mounted under the rear deck on coupes and on the rear bulkhead on convertibles.
All non a/c cars had them, while a/c cars did not and instead had a metal block-off plate in place of the doors. The a/c cars still had the plenums and deck grills.
Regards,
Alan

There are lot's of nice car's running around without the black-out on the top of the doors or on the surround gutter at the wiper bay. Some might say the compartment looks nicer with the whole surround gutter painted exterior color.

 

On the early 68 cars the lip at the top of the firewall was body color and the astro ventilation doors were in fact foam flaps, at least thats the way mine was.

 

Alan, thanks for the help clarifying the area of concern.
So, No doors, only foam flaps on 68's. I never had a reason to notice before. Guess its just one of those 68 only items.

Now we have answers both ways on the paint on the lip of the firewall/cowl. I did not check to see what the vin number was. I do not know if it was early or late.

Bob68, do you recall on your 68 if the door was blacked out between the panel and the hinge side weatherstrip?


I did find a lot of pictures with a Google search on 68, and saw a lot of nice cars with no black on the lip in question, but I agree with Alan that that could be a personal preference with a repaint. The door blackout treatment seemed to hit or miss as well.

 

Hi,
Bob's right about early 68 cars not having a painted gutter between the compartment and wiper bay.
I can't imagine how the 68 astro system would work without the metal 'flapper' doors and vacuum actuator.
Regards,
Alan

 

A lot of changes occurred during the 1968 model years as you have noticed.

Question 1: Early 68 cars had the firewall/cowl area painted body color. Later cars had this area blacked out as on 1969 and later cars.

Question 2: This area was not blacked out on early cars but was on late production cars.

Question 3: 1968 cars did not have the vacuum actuator and doors on rear bulkhead for the astro ventilation system. It was only the rubber flaps.

John

 

Alan

The rear Astro-ventilation flaps are only closed when the temperature control wheel is turned towards hot. This will close the flaps to help quickly heat the car interior. The operation of the flaps are vacuum controlled only through the temperature control wheel. The flaps are spring loaded to be open otherwise. Other than this they serve no purpose.

John

 

Hi John,
Too much confusion.
Foam rubber flaps, metal doors and mechanism, vacuum actuator, copper line/rubber line, controlled by temperature control thumb wheel.
On all cars without a/c from the beginning.
Regards,
Alan

 

Hi Alan, I'm confused [comes with age], I have two 68s in shop both non a/c, an early conv and a late coupe. Neither ones has any vacuum control or any provisions for the rear vents in the deck. There is a soft foam rubber flap that I think moves if to cabin air pressure is to high, allowing air to escape. Could be wrong, I'm just trying to figure out what GM actually means by the term 'ASTO VENTILATION'. What I see is two control calbes on console to operate kick panel vents and the chrome ***** in the lower dash pads operated on the conv via hard to reach levers behind dash pad and no levers on coupe. With the rear vents to allow air out. Isn't that the ASTRO system? Thanks T

 

I have original owner 1968 convertible, the rear vents in the rear of the luggage compartment only open when the flow of air from the front dash area or open windows forces them open when driving. No vacuum operation like later year C3's. My 68's rear vents are still the original 47 year old installation from the factory and are in a pretty much worn material condition. I may someday replace them. Built in Feb 1968.

 

Alan

1968 Corvettes do not have the metal doors or any type of vacuum actuator for the Astro ventilation system. All of that started in 1969.

John

 

Hi Terry,
I guess I don't know enough about 68s to be sure of the facts. It seems to me that at least on coupes if there were no metal doors the rubber flaps would just droop straight down and there's certainly not enough air flow to ever 'suck' them closed.
The cars I'm familiar with use the temperature thumb-wheel on the heater/defroster controller to send a vacuum signal to the astro 'flapper' door actuator when the thumb-wheel is turned to H. It lets the heater warm the air in the interior instead of continuously moving air out the rear of the interior.
There's a short piece of very small rubber hose coming off the h/d controller that connects to a long piece of very small, soft, copper tubing that snakes back along the transmission tunnel, across the seat bulkhead, up the lock pillar, to where it transitions back to rubber hose and then connects to the actuator.
It's really a very simple system if the actuator is working.
The way astro ventilation was touted in the literature I'm surprised Chevrolet tried it without the flapper doors and actuator.
???
Regards,
Alan

The small actuator. (disregard the arrows)


The copper tube running along the tunnel on the passengers side and then crossing to the driver's side of the bulkhead.


The copper tube going up the lock pillar.


The actuator and plenum. Also the clamp for the plenum's rubber drain tube and the flapper door jutting up toward the left.

 

My Jan 68 build non-A/C convertible has none of the parts in Alan71's pics as far as I'm aware of. Additionally, when I changed the blower motor switch I didn't notice any vacuum lines on the HVAC controls.

 

Attached are pictures of what the Astro Ventilation system looks like on the rear wall of the luggage compartment on a 1968 convertible with no AC.

John