tdatk944+S4

Has anyone got any pics of a decient looking replacement /delete/re-routing of the hoses from the heater boxes on a 80's SC? I am cleaning up the engine and there is no way I'm gonna settle for the stock setup. Please attach pics to se what you crafty guy's/gals are up to. I had been thinking of deleting the cross engine hose, as anyone been there?

Tim
Current eng.

DGaunt

If you delete the croos-engine hose, you will delete the forced air to the passenger side of the car. Might be a good strategy to keep the passenger seat empty though...

i replaced my paper hose with orange silicon hose. It is durable,works well andlooks pretty good. Bit of a bear to keep clean though.

Sorry no Digi cam, no pics.

bones

I think what you are looking for is a heater backdate, do a search see what comes up this is a common SC mod.

CDiercks

I think a backdate is the way to go too. Attached below is my engine before dropping it for a tranny rebuild and a cleaning. Since then I have added in only the left side heater tube and the blower motor and eliminated the hose across the engine. In the future, I am going to eliminate the blower and blower tube again and add carrera footwell blowers for heat. I have heard people have done this with good success.

Bones: How loud is your car now that you have removed the engine sound pad compared to when it was in place? I'm thinking of doing that since mine is pretty ragged.

bones

Hey, engine's looking good , how about tidying up the fan? I can't tell if there is any difference because I have a Triad 2 in 2 out exhaust and it's pretty loud and wild. The performance improvement with this set up is astonishing.

CDiercks

Acctualy when I rebuilt my tranny about two months ago, I painted the fan and fan schroud, repainted the engine tinn, and cleaned the engine and compartment really well. It really looks much better now then in that picture. I need to get a new picture of it sometime.

Bill Gregory

Here's what I posted awhile ago....

Retrofitting pre-1974 Hot Air Source

Shortly after introducing CIS fuel injection in 1974/1975, Porsche changed how hot air was sent into the passenger cabin for heat and defrostings. Starting with the first 911 in 1965, the original air system consisted of a duct on either side of the fan housing routing air through the engine tin to the heat exchangers. The new mid-70's system consisted of a fan mounted high on the left upper side of the engine bay, with 3 hoses, one for an air intake from the fan housing, and two hoses from the blower through the engine tin to each heat exchanger. Backdating the air system to the older style is easy to do, and Porsche sells the parts you'll need, or you can visit your favorite used parts dealer.

You'll need the following parts:

Left hot air duct, 930.106.321.02, list $148.20
4 plastic nuts, 999.591.592.40, list $.12 each
2 rubber plugs, 999.703.044.50, list $.77 each
Right hot air duct, 911.106.327.00, list $53.45
Right engine cover plate, 911.106.036.00, list $14.89
Right engine cover, 911.106.827.00, list $5.04
Right air duct support, 911.106.331.00, list $1.30
Hose (see below)

The left hand air duct has a bunch of holes in it to fit 911's and 930's, and the rubber plugs and plastic nuts cover those holes and allow other things to be screwed to the housing. I put a screw into each plastic nut to pretty well close off those holes. The left hot air duct is metal, and the right duct is plastic, while the right hand engine cover and plate are metal. The right air duct support is to bolt the right air duct to the larger plastic cover over the engine. I didn't use it, as things seem tight enough without it, however, we'll see if over time I need to add the support.

Installation is straight forward, take the existing blower and hoses out of the engine. On my 81SC, the bracket that holds the motor also holds one of the vacuum pipes, so I took the whole bracket off, and cut off the portion which held the motor, leaving the portion that holds a support for the pipe. Put the left hot air duct in. On the right, unscrew the cover plate and remove it. Put in the engine cover plate, followed by the right air duct, followed by the engine cover. The right air duct has some grooves in it where the engine cover cinches it up fairly tight.

Hoses: I used 4 feet of 2 1/2" SCAT hose (silcone rubber-based, good to 450 degrees) from Aircraft Spruce and Specialty. You'll cut two pieces for the left side (duct to engine tin, then below engine tin to heat exchanger) and one longer piece on the right (duct to heat exchanger). I've also seen an aluminum-based hose used, as well as other types and colors. The hose has to stand the heat in the engine compartment and more importantly the heat at the heat exchanger connection.

That completes the installation. Assuming your heater boxes are working, and the wires to the heater controls on the floor are also intact, you're done! Not much heat at idle, it picks up well as the revs increase. If you open a window just a crack, then that helps the heated air move into the compartment. And you can now see, and access, more of the engine!

randyrap

Getting rid of the AC and backdating the heater was one of the first things I did with my car. Much easier to work on and it also saved a lot of weight.

Thanks ..................................... Randy

KC911

Thanks Bill for the comprehensive parts list! Does everything you've mentioned also apply to an '88 (as far as you know)?

Keith