Heater questions...

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acarlson
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Location: Dahlonega, GA

Heater questions...

Post by acarlson »

Some previous owner removed the fresh air hose from the top engine shroud to the heater blower. He did a reasonable covering the hole in the shroud and the firewall with cover plates but he just put duct tape over the input to the blower. I'll have to fix that.

My question is - do I really need a fresh air supply ??? I would not normally use it and so my question actually has more to do with the heat then cool air.

Is the heater temperature regulated by blending both hot and fresh air from the engine shrouds ?

If so, I guess I'll need to re-install the fresh air hose (and that brings me to my next question): Is there a fresh air hose bracket in the firewall or does the hose just run through the firewall to the blower ? There are no brackets there for a fresh air supply...
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
66vairguy
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Re: Heater questions...

Post by 66vairguy »

The opinions on the fresh air hose being required are divided.

Basically the hose tends to split and leak engine cooling air due to age after a decade or so. When it leaks air the #5 cylinder and head area can run hot. Many have stated the #5 cylinder has a greater tendency to drop the valve seat(s). So it was assumed the fresh air hose is the culprit and people started blocking off the air outlet on the shroud. GM did a lot of testing and never found an issue with a hot spot at cylinder # 5 if the hose and heater were in proper condition.

Note the heater air box has two rubber sealed flappers that must be in good shape. When you set the heater temp lever to OFF it should block any cooling air from the engine top shroud so the hose must be intact or it leaks air.

Changing the hose and removing the heater mix box is VERY difficult with the power train in the car. When I drop a power train I always remove the heater box, dismantle, inspect/repair, and assemble. I also put in a new fresh air hose if needed. The hose runs from the engine through the bulkhead (there is a big rubber grommet) to the heater box.

YES you can use your heater with NO fresh air hose. The fresh air hose provided pressurized cool air to mix with the pressurized hot air so you can use the heater without the fan. If the fresh air hose is not connected you should use the heater fan to force hot air to the interior. If the fan is off and you turn on the heat with the lever, especially just part way, then a lot of the hot air off the engine will exit out the fresh air inlet on the heater box.

It comes down to how original you want the system and how much work you want to do. Using the fan is not a big issue if you want to leave the fresh air hose off and block off the outlet on the engine top shroud.
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acarlson
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Location: Dahlonega, GA

Re: Heater questions...

Post by acarlson »

Ahh, thanks for the overview. That fills in a number of my questions. I have the engine and drive train out of the car right now. I wasn't even considering inspecting the heater blower assembly but now that you mention it, I suppose I should take a look while I can. Thanks for your help.

Alec
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
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terribleted
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Re: Heater questions...

Post by terribleted »

There is no bracketing for the fresh air hose. There is a formed metal insert grommet to protect where it comes through the oval hole in the firewall. All there is, is the flange where the hose goes onto the heater and the circular flanged shrouding piece that links it to the top shroud of the engine and the grommet through the firewall.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia
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acarlson
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Location: Dahlonega, GA

Re: Heater questions...

Post by acarlson »

terribleted wrote: Sun May 07, 2017 12:06 pm ...and the circular flanged shrouding piece that links it to the top shroud of the engine and the grommet through the firewall.
That would be the piece I'm missing if I re-installed the hose. I'll check with Clarks or Corvair Ranch and see what they want for one. Thanks !
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
66vairguy
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Joined: Tue Dec 21, 2010 3:44 pm

Re: Heater questions...

Post by 66vairguy »

While your at it run a ground wire (same gauge as supply wire, or bigger) from the fan motor shroud to the heater to body bracket. It will reduce the resistance in the fan motor ground path and the fan will run faster.

I tried to attach a .jpg of the ground wire installation, but I could not get it to work - AHHHHH!
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acarlson
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Location: Dahlonega, GA

Re: Heater questions...

Post by acarlson »

66vairguy wrote: Sun May 07, 2017 3:24 pm While your at it run a ground wire (same gauge as supply wire, or bigger) from the fan motor shroud to the heater to body bracket. It will reduce the resistance in the fan motor ground path and the fan will run faster.

I tried to attach a .jpg of the ground wire installation, but I could not get it to work - AHHHHH!
Email it to me - AlecCarlson@cincotek.c.o.m (remove extra .'s) and I'll post it here.

Alec
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
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acarlson
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Joined: Wed Nov 02, 2016 5:54 pm
Location: Dahlonega, GA

Re: Heater questions...

Post by acarlson »

Here is the wiring pict from 66VairGuy:
Heater ground wire.jpg
Alec
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
66vairguy
Posts: 4531
Joined: Tue Dec 21, 2010 3:44 pm

Re: Heater questions...

Post by 66vairguy »

Here's a site that explains electric car heaters. See https://www.lifewire.com/12v-electric-p ... ers-534675

Note that the better electric heaters (still less heat than a stock Corvair heater) require either 30 or 60 Amps!!! A stock Corvair alternator puts out 37Amps MAXIMUM!! (45 Amp for A/C cars). You can upgrade to an internally regulated 63 Amp unit, but you would have to modify the wiring and don't expect 63 Amps except at higher RPM. So unless you run a dedicated separate alternator the practical limit is about 15 Amps (you have to allow for other car electrical items like lights). There are higher output alternators, but the fan's are counter rotation to the Corvair engine. So you'd have to mount them in an odd position so the fan worked. All doable, but far more trouble than fixing the regular heater system.
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