68 interior heat issues

[Walter F.]

Is it true that the first year 1968 C3 had interior heat issues that made the car almost impossible to use in warm weather ?

[Gene M.]

Re: 68 interior heat issues

no it is not, mine is no different than my 67 or 65

do you have a modified big block?

[Mike E.]

Re: 68 interior heat issues

No. Some early cars had engine heating issues. GM enlarged the holes in the lower valance to helpmwith that.

[Don W.]

Re: 68 interior heat issues

welcome to the C3 family with "astro ventilation" where astro = the sun venting into the cockpit area. Don 69 427 coupe, no A/C

[Reba W.]

Re: 68 interior heat issues

Sometime during production (ca. April I think), insulation was added to the outer two storage compartments to address the heat issue. It must not have been successful as it was discontinued within a month or two. Occasionally, it is still present in judged cars built during that period.

[Jeff W.]

Re: 68 interior heat issues

Since I only own a '68, I find Gene's perspective very interesting. The difference from early years is probably the elimination of side vents at the windows. And, yes, Reba, whoever dreamed up those storage box insulation things had no clue. The worst heat is at your feet. After installing aluminum backed heavy vinyl in my car, the heat continues to build near the firewall with longer drives. I always wondered if the shields introduced in '69 (?) would be helpful, even if deinstalled for occasional judging

[John C.]

Re: 68 interior heat issues

Yes a 68 interior can be hot compared to a modern car, but so was the interior of my 66, 67, and 69. All were big blocks. At least on the midyears you could use the side wing windows to help get outside air to the interior. The Astro Ventilation system is pretty worthless in this regard.

They added various insulation pieces over the course of the model year to the rear stowage compartments and lower firewall/floorboard to try to help, but none of these lasted long in production so I think is shows how effective they were.

One thing they did change that I do think makes a difference, is the switch from the early cars having the triangular metal splash shields that ran from the floorboard to the frame to the latter cars having the white plastic shields that that were mounted to the firewall. The triangular shields hold the engine heat up near the firewall. The plastic shields push the heat down and under the car to escape.

On my 68 with the triangular shields I removed them and it made a noticeable difference in interior temperature.

John

[Don W.]

Re: 68 interior heat issues

the only real cooling option I've seen work is to remove the T-Tops and rear window and let fresh air cool the cabin.

[Gene M.]

Re: 68 interior heat issues

A 68 is nothing more than a c2 frame with a c3 body. That is rather simple but the ride as far as comfort falls short compared to a mid year in room and seat comfort. Maybe the side to side tightness is what makes you feel "uncomfortable".

I prefer the vent windows that a 68 lacks, but I leave the window wide open all the time when riding with hardtop. But honestly I see no difference in interior temp between 68 and 67/65 all being SB.