Low budget heat system in 911 Hotrod

[puddy]

I have a 1975 911 and all heater / blowers have been removed except the blower motor in the frunk. I have B&B headers with heat exchangers on them but no hoses on them. I'm wondering if I install the factory hoses onto the heat exchangers will some heat trickle into the cabin on its own? I don't want to add blowers etc back into the car. I'd rather sell the original blower pieces, if they are worth something to someone.

I'd like to understand how the whole system works, does anyone have a good diagram of how the heater system goes together? I tried to google it but didn't really find anything that looked right for me.

[javadog]

You will get heat without any blower motors. Plenty, in fact.

It's been discussed here about a million times, so search again. Look for "back dated" heat.

JR

[puddy]

OK backdated heat, i'll search that, thanks JR!!

[puddy]

OK, after searching backdated heat, it seems folks are leaving all the ducting on the motor but removing the blower motor? However I have no heater ducting what so ever, all I have is the heat exchangers on my headers so I was hoping that if I reinstall the heater valves from the heat exchangers to the body of the car and try to reinstall the red heat levers on the E-brake handle that maybe I can get a little heat when wanted by just opening or closing the red handles at the E-brake. Would that work?

[Josh D]

Originally Posted by puddy

OK, after searching backdated heat, it seems folks are leaving all the ducting on the motor but removing the blower motor? However I have no heater ducting what so ever, all I have is the heat exchangers on my headers so I was hoping that if I reinstall the heater valves from the heat exchangers to the body of the car and try to reinstall the red heat levers on the E-brake handle that maybe I can get a little heat when wanted by just opening or closing the red handles at the E-brake. Would that work?

You would have to have the heater ducts on the motor and hoses connecting them to the heat exchangers, plus the heater valves, levers, etc.

Or just get heated seat elements and wire them up.

[JohnJL]

Lightest is just adding heated elements to your seats, 12v hairdrier to your driver defrost vent. Then ditch everything else and free up header choices.

[Jack Stands]

Getting the proper air outlets on the engine will give you plenty of air to blow through the heat exchangers. Simple and not heavy at all. Should be able to get the parts by posting a WTB on the classified section.

[pors1968]

The heat system on 65-68 SWB no blower motor is lightest you can have.

[will hung]

Our host sells the ducting on each side of your cooling fan. I recommend installing them either way. The heat exchangers hold heat, so even when you aren't using that heat to warm your cabin, the valves close at the body, but open to the atmosphere, so your cooling fan pushes the hot air out of the heat exchangers. So basically, enabling the heat to set there can cause your engine to run too hot.

[puddy]

One problem I think i have is that my engine tin has been modified or patched up, so its not goign to be as easy as putting new heater hoses onto existing heat shields on the motor. I have a 3.3 turbo motor and there is a not alot of room with my turbo pipes and large aftermarket intercooler. I'll have a better look tonight when i'm at home.

[Tremelune]

You must duct from the exchangers to the chassis inlets, and you must force the air forward somehow. The heat will not wander forward on its own, and it won't get sucked into the cabin due to pressure changes from speed.

The simplest way to force the heat would be the footwell blowers. A better way would be the engine fan (which would required ducting to the exchanger inlets in addition). With the engine fan and no other blowers you will get great heat but no defrost.

If the car is in Canada, I would definitely install ducting from the engine fan, to both exhchangers, to both flappers, to both chassis inlets, and go from there.

The ducting you want is SCEET if you clamp it directly to the exchanger (due to the high temps), or CEET if you don't (by using silicone sleeves and metal inserts). This is what I did:

Winter is coming - Getting heat into an M491 with a 3.6

[vintagecarlover]

Depends on how low cost you want to go. Here is a small electric heater that I picked up at a flea market. It runs on 120v but u can buy a small power inverter and if creative wire inverter into fuse panel and either mount under dash or duct into current duct system inside dash thru trunk. Will heat a fair size bathroom at my cabin in 10 mins.

[puddy]

After having a closer look at things last night i'm not going to bother adding the original hoses back onto the car, its too much effort to undo things the previous owner did. I thought It would be a nice little perk to have however i'm not interested in driving her in cold temperatures anyways, and my front cold air fan works to keep the windows clear in cool temperatures so i'll survive with that. I'll see what I think after my first full season of driving this car. Maybe i'll change my mind?