Hot Box 1977

[joe palmer]

I love driving my vette. Problem is during the summer it feels like a suna. The engin gives off a tremendous amount of heat. Purchased a kit for the floor it helped very little. Hot air enters the car from the floor, dash, kick panels, etc. Its a waste of time to use the AC it doesn't help. When I purchased the car, all components of the polution system had been removed. It has dual exhaust w/o converters. Is their a cure for the heat.

Thanks

[Clem Z.]

it a sports car it is supposed to be uncomfortable

hell the cobras floor got so hot the melted the rubber soles of your shoes. PS if its got headers that is your problem

[lyndon sharpton]

Re: Hot Box 1977

look an see if you have the transmission collar on the bellhousing, an the tunnel insulator. that might help if they are missing. I know my 454 feels like what you are describing.

[Harmon C.]

Re: Hot Box 1977

Joe
With A/C you have no floor vent on the drivers side and with the air not working it is a hot box. If the air is working the way it should and all the heater box doors and heat shields are in place the cabin would be cool.
Lyle

[Dick W.]

Re: Hot Box 1977

Check the firewall and make sure all the grommets are there. Should be no holes to allow engine compartment heat inside. It also sounds like that you are still getting heat from the heater core. Is the water shutoff working? (does 77 have one?) I would consider using an inline cut off valve to stop the water flow.

Has the carpet been replaced and the jute backing removed?

Just a few obvious items to those of us that have had a Vette for several years. Very common problem

[don izzo]

Re: Hot Box 1977

Joe, My 68 convt. gets so hot I just leave it home when the temps climb over 90 degrees. I pulled out the rugs and installed insulation that I got from a hot rod shop. They recommend it's use in all street rods that have fiberglass repro bodies. It helped a little but not enough to make it comfortable. I will tell you that I don't have this problem with my 60. Maybe it's the cowl that allows fresh air to enter the cockpit.
Don

[Jack H.]

Re: Hot Box 1977

Here's one trick that works GREAT for a 'driver' car application... Go to the local autoparts store and purchase an in-line, manual water shut-off valve. With an extra piece of hose install it between the water pump's outlet nipple and your existing, factory stock, heater hose. Should you want to have the car judged, it comes out just as easily as it went in...

Part of the problem is the A/C system is a 're-heat' design. It's possible to dial in the exact outlet temp you're after by varying the setting of the Hot/Cold control lever. This changes position of the interior air box's deflector to run some portion of the total makeup air that's gone through the A/C evaporator (cold air) through the active heater core and deliver a mixture of hot/cold air....

The only time the heater core is fully shut down via the A/C system's vacuum controlled shut-off valve is when you've set the center console controls for MAX A/C. Soooo, in most cases when you're driving the heater core is active and hot....

Now, UNLESS the seals on the A/C heater box are 'perfect' (they NEVER are), you can expect some leakage/blow-by through the system due to the ram-effect of motion (low pressure in the cockpit + high pressure in the cowl + engine compartment) and you'll get air infiltrating through the ducts with some of this air having gone around/through the hot, active, heater core. The faster you go, the more leakage. Roll down the windows, pop the T-tops, or put down the soft top and cockpit low pressure increases with infiltration rising in lock-step.

Play a game to check this hypothesis out. Get on the road and re-create the situation where the interior is HOT. Have your passenger run his hands near the various air duct outlets and check for warm/hot air infiltration. If you attempt this yourself, from the driver's seat, be CAREFUL to check when there's no danger of oncomming/adjacent traffic!!!

[Tom R.]

Re: Hot Box 1977

Joe:

It's a combination of methods that will reduce that cabin heat well described above from each contributor. If you wish to fully understand the engineering limitations of C3 engine cooling and cabin cooling get a copy of "Air Conditioning Strategies for the 1963-1982 Corvette by Michael Davis.

[Clem Z.]

try this website

http://home.comcast.net/~chadwick.robert/ventilation.htm