[rev'sc3]

I'm looking for cleaver ideas on how to cool off the engine compartment, and thus cool down the interior of the car. I'v put headers on the engine, which of course did not help the situation any at all. So far I'v: insulated under the carpet, over the tranny hump; removed the heater water hoses; placed insulation over the exterior of the evaporator box in the engine compartment; placed header covers over the upper most parts of the headers, where they come off the head, and curve down; made a metal shield between the #8 cylinder header and the evaporator box - and the heat still finds a way in. Its not as bad as before but its still there. My concern is trying to use the a/c with the evaporator box so hot. I saw where someone mounted electric radiator fans on both sides of the engine, down near the frame to pull the hot air out and blow it under the car - I haven't received the fans yet but will put them in when they come. Any other cleaver ideas? I've also had someone tell me that the a/c heater fan is supposed to run on low, when the system is shut off completely, thus always letting hot air blow in through the duct work. Is that true?

thanks:huh:

 

[SIXFOOTER]

So what did you put under the carpet?
you need to make sure the outside air flap in front of the pass lower corner of the windshield is working. It is vac operated from the vac selector switch on the center console. With the selector set to max it is supposed to close the flap and recirculate air inside the cabin. There is also a rubber gasket on the door in the pass side vent that may need to be replaced.

 

[glasrtlr]

best thing we found was ''heat shields'' under the floor pan, made from thin aluminum (used roof flashing IIRC ) and mounted to give a 1/4'' air space between the heat shield and the floor pan...much more effective than adding insulation ...double layer heat shields with two air gaps helped even more, but things get tight.

 

[ecordeddie]

...make sure your hood weather strip is good too.... good weather strip here seals out the heat from getting into your cabin air intake vents...

 

[rev'sc3]

its hot in here

I put double sided aluminum type insulation under the carpet. Its a flexible material, with foam in the center of two outer "light weight metal" materials. The vacumm system on the a/c is not working, so I closed the flap on the outside, over the firewall which lets in outside air, and secured the one at the passenger's feet open, to recirculate the interior air. I do like the idea of putting a shield under the flloor boards. Sounds like a pain in the rear to do, but not impossible. thanks

 

[6880 Mike]

Reflectix or similar under the carpet.

Make sure the heater/deforster box seals are in good shape.

Make sure all the various holes in the firewall are plugged and sealed.

Make sure you don't have an exhaust leak.

If you have factory AC, make sure the water valve closes when it's supposed to close and ensure the flapper door on the cowl is doing it's correct thing.

If your car has underbody heat shields, make sure they're still there.

Depending upon the year, you can have a tranny collar and various frame shields keeping warm air out of the interior.

Kick panel vent flaps should have good rubber seals.

Correct thermostat in the car? Operable fan clutch?

:thumbsup:

 

[rev'sc3]

What's the right temp for the thermostat? right now I put in a new 185 degree, and car runs pretty much right there. Any good ways to assure the clutch is good on the fan? I certainly assume it is. thanks

 

[SIXFOOTER]

180*, is the normal one to use. Remember, thermostat sets the Minumum operating temp.

 

[rev'sc3]

thanks - I'll change it, even though its not much different. How about the fan clutch? My fan spins pretty easy by hand; it does not simply whirl around absolutely free, but at the same time, its not hard to spin at all, I guess "sluggish" describes it best.:huh:

 

[6880 Mike]

...How about the fan clutch? My fan spins pretty easy by hand; it does not simply whirl around absolutely free, but at the same time, its not hard to spin at all, I guess "sluggish" describes it best.:huh:

Car running hot?

Rule of thumb for checking fan clutches: Bring the car to operating temperature. Have a co-pilot turn off the engine. If the fan and clutch freewheel more than three revolutions after engine shut down, you probably need a fan clutch.

:thumbsup:

 

[rev'sc3]

thanks

 

[Corvette7579]

I pop the hood when I drive (unpopular to some,? hot air rises). I am almost done dynamating the floor and then the back deck. By the time the new carpet goes in and then the carpet boots from Ecklers it should be cool on the feet also. I would check the firewall for holes that let heat in the cabin and go to the local glass dealer and ask for a tube of adhesive used to secure the windshield in place to fill in the holes if any. I had a gap where a cable was run through the firewall. Those rubber bushings work but not to keep the heat outta there. Exhaust leaks are a big factor. Those flaps also. I do not have my AC unit on at the time for repairs to it. I found a roll of something on e-bay that is not dynamat but thinner and might put some on the firewall. They say alot of the heat is from the tunnel where the tranny is and the proper way is to line it from underneath when the engine is out the vehicle. Myself I think they were right. Now you can mabey use a rubberized paint from Eastwood with the air gun they suggest, I have one and did all the fender wells on the 79 with that thing. It works well. Sure easier to wash under there now. Did the part of the engine bay too and the back of the firewall. Kinda wish I woulda done the darn crossmember and the other things when I had the radiator outta the thing. If you find another answer, let us know.

 

[my72vette454]

My car was always hot, started out with a small block then a big block. I had heddman headers with the big block and they sat so close to the floorboard that they actually damaged the floorboard in one place. When I put the twin turbo setup on the car and added sidepipes so I had no exhaust under the car, it completly cured the interior heat problem so I blame most of it (at least in my case) on the under car exhaust. One of these days when I get around to doing the frame off resto, after I get the cabin insulated, I might try the exhaust back under the car just to see if it gets hot again. The sidepipes are nice and sound gnarly but ( I must be getting old..) they are tiring to listen to on long trips.