Ventilation/Heating w/o blowers

[Wout_RS]

Hi guys,

I was tackling some electric grimlims this weekend on the '80 SC.
Due to the previous owner who had removed an aftermarket A/C, their were a lot of loose ends.

While doing that, I saw that my hot air blower on the engine was coming apart.


As the ventilation/heating never worked since I got the car, I uninstalled already most of the part (for temporary).

The direction I want to go with this car is as light possible, but with the original look.
So I was thinking of getting rid of all the ventilation/heating as this is a lot of 'dead' weight for the moment.
I was wandering if you drive in autumn, how do cars without this, get ventilated?
Driving in that period, you can get often damp windows.

Also if I remove everything from the heating/ventilation, should I remove all electrical harnesses or just remove the fuses? As I want it all to be reversible if I want to sell the car?


thanks!

[SkiVT]

Search for "backdating heat" to see a lightweight way to remove the rear blower while keeping some warmth and windshield de-fog.

If the heat doesnt work today, removing the rear blower will not impact anything you describe (ventilation, defogging). The fresh air flow comes from the front of the car. I removed all AC componants, rear blower, but installed new heater flapper boxes and backdated the hot air flow off the engine. This gives me the heat needed for comfort and defog in spring/fall.

[Flojo]

exactly.

Wout, you have PM

[Wout_RS]

That's clear!

Thanks all!

Should I remove all fuses related to the ventilation, heating if I delete the components?

[Flojo]

There is no real need to remove the fuses or delete any of the wireing.
At least mine is still all in place. No issues.

[kavadarci]

Just did this myself.
I don’t plan to drive winter time and backdate heat is all I need for spring fall time.
I didn’t care about ye weight but I sure like the clean look without the copious amount of hoses.

[Otter74]

Wout, I have a Targa with correctly backdated heat and have no trouble defogging the windshield when needed. I also find it produces enough heat to keep me warm in any spring through fall conditions I'm likely to encounter. I'll drive the car in any conditions that don't involve salty roads or temperatures too cold for the oil, though in practice it is not driven in winter. With the top on it will keep me warm in any weather, and with the top off at highway speeds (~130kph) I'm warm down to around 10C with the top off and windows up with the heater on and a jacket, hat and gloves. So it should be more than good enough for your use case.

[Wout_RS]

Thanks for the advice guys!

Great pictures also Kavadarci! This will be a enormous help!

If you backdate the heat, do the controls on the console work? If you block of the heat, will it then be blocked?
Or is the heat automatically send when backdated?

And indeed the times I drive the car, I don't need the hot air but cold fresh air

[pmax]

The console levers control little flappers and elves for cold/hot air distribution. The red levers between the seats open and close the heater box valves connected to your heat exchangers.

Backdating doesn't change that. The extra blower above the engine on the driver's side and the long ugly hose snake is what's removed. I keep mine for the extra heat since I'm not the only one who will be riding in this.

[OldSpool87]

I have a backdated SC with heat plumbed to the defrost vents on. I live in New York and drive 1.5 hours to the track often in the Fall and Spring. Cabin is plenty toasty on chilly mornings. I might try to get a little heat to the footwell as my feet got a little cold on the last run up.

[Targalid]

Hey Kava! That sure is purdy! Great job!

[Wout_RS]

I was searching for the backdated heating.

Can it be that it's no a one two three job, and it needs some prepping?

I was hoping to drive this weekend with the nice weather forecast.
Can I drive the car without hoses? Or will there be to much heat in the engine compartment

[pampadori]

Originally Posted by Wout_RS

I was searching for the backdated heating.

Can it be that it's no a one two three job, and it needs some prepping?

I was hoping to drive this weekend with the nice weather forecast.
Can I drive the car without hoses? Or will there be to much heat in the engine compartment

If you don't have block off plates to the left and right of the alternator where the heat tubes are normally found on backdated heat setups, then you shouldn't drive the car without the heat tubes connected. It results in not enough cooling air to be forced thru the cylinders and thru the oil cooler on the right front corner of the motor. Air will take the path of least resistance and that ends up being the two unconnected heater hose connections.

Thats my opinion. You might would be ok if its a short drive or if temps are cool enough but what if you hit a traffic jam or something? You could overheat pretty fast in that scenario.

[pmax]

Originally Posted by Targalid

Hey Kava! That sure is purdy! Great job!

Even has a blanket to keep the cat warm.

[pmax]

And yes, as a temporary solution, I would just tape up the heater port (driver side).

[Wout_RS]

Hmm, that's probably why it's always that damn hot in the engine bay.

When I got the car from the PO, there was a hole on the right side, were tubing was missing.
Never saw a point of problem in it.
But no I see it's one of the tubing for the heating that was missing.

[kavadarci]

Originally Posted by pmax

Even has a blanket to keep the cat warm.

Lol

[Steam Driver]

All of these discussions about heat baffle me some. I drove 911’s and my 914-6 as daily drivers in Kansas City winters “back in the day” and I never remember being cold, nor were there complaints from the passenger side either. And defogging/de icing worked fine. Just keep the revs up - my normal operating range was 2500-4000.

The same thing applies to the 914-4. I had one of those as well and can probably count the times I used the assist blower on it on the fingers of on hand. I guess we’ve become acclimated to better.

The 356C was, however, another story. I had about a 15 mile commute and I would leave with a cup of coffee. By the time I got to work the drops left in the cup would be frozen!

In any case the engine compartment blower has departed my SC, never to return!

[Wout_RS]

Excuse me for the probably dumb question (I will probably find it this weekend when I have a closer look to the engine).

For the backdated heat, you just connect two hoses from the heat exchangers and send it next to the fan, underneath the shield.
The hot air gets there, and what happens then?
Are the tubing running from under the shield to the front of the car for the distribution?

[OldSpool87]

The air exits the exchangers towards the front of the car and connects to the flapper boxes. From there it is routed to ducts that run along each rocker. You can’t really see them. The ducts terminate in the wheel wells if I’m not mistaken. From there distribution continues via flex hoses.