heat backdate question

[dan79brooklyn]

OK- I have removed all the AC components and am now considering removing the heater blower and backdating the heat.
(1979 SC)
This is my question :
Were is the heat routed to? does it just get expelled from behind the fan and disperse or is routed back into the heat exchangers?
I am not so familiar with how the heat works in my car. I have SSI and dual B&B (from the PO) on the car if that makes a difference and I would like to keep the somewhat adequete heat which the car currently delivers, but like the looks and simplicity of the backdate.

Thanks for the edification,

Dan

[ianc]

In stock form, air is blown by the engine fan through that black plastic accordian shaped hose to the blower fan. The fan housing has a Y pipe that diverts the air to each of the two heat exchangers. From the heat exchangers, it goes to the flapper boxes, which route the heat forward to be distributed by the confusing array of levers in the dash.

ianc

[dan79brooklyn]

So when the heat is backdated the tubes that come out of the rear of the heat exchangers is simply routed to the engine fan and the heat is blown out through the fan?

[5speed]

dan79brooklyn - you've got the flow of air backwards. The large engine/alternator fan sucks air in and blows it fowards towards the cylinders. Some of the air is diverted towards the sides of the fan housing. In stock form the cool air that comes out of the left side of the housing goes up the tube to the heater blower which boosts and splits cool air down to the left and right heat exchangers. The air is heated and the heater flapper valves either dumps the heat if the heat is off or moves forward to the cabin if the heat is on. When you backdate you remove the heater blower and associated tubes and replace the left and right output ducts of the fan housing. Some of the cool air will now move directly out the left and right of the engine fan down to the back of heat exchangers.

[dan79brooklyn]

I got it! Thanks guys.

[Dan in Pasadena]

Now, does anyone know a good (cheap?) source for the right side backdate duct for my '76 2.7? I have the driver's side, I just need the other one and don't want to spend $130 for one of those fiberglass ones. I've got plenty of other $130 things to do!

[PatrickM]

Dan, your best bet a salvage yard or parts place like Parts Heaven. I picked mine up at Gary Emory's place in McMinnville, Or.

Check one of these places.....
http://20thstreetauto.com/parts.htm

http://oklahomaforeign.com/

http://www.partsheaven.com/

http://www.911pcar.com/

[widebody911]

Originally posted by Dan in Pasadena
I have the driver's side, I just need the other one and don't want to spend $130 for one of those fiberglass ones. I've got plenty of other $130 things to do!

Hit the junkyards, swaps, and Pelican classifieds.

I encourage people to find used right-side ducts - they are a royal PITA to make