Backdating Heat - Questions?

[jcc911]

I am in the middle of backdating the heat and I am still trying to source a set of the original "early style" ducts.

My specific questions are,
What are the number pieces per side, or is each side one piece (as I noticed that my drivers side SC duct is 2 pieces)?
Do the early ducts has the same number of mounting holes or more/less?

Detailed pics or close ups of the early style ducts would be greatly appreciated.

Thanks Guys.

[Ian Comerford]

Hi JCC,
I recently completed this job on my '79 SC. I spent ages looking for the parts from various breakers and in the end I gave up and went online to Mittelmotor in Germany. They have a great online catalogue and speak excellent technical English, an easy shopping experience. Give them a go

Ian

[jcc911]

Ian, I am on their web site now. Thanks it is a big help.
Do you have part numbers of the items you ordered?
How many pieces do i order?
Right now I am at 5 pices, but do I need the support plate or the buckle?
Thanks again for your help.

[DW SD]

For Carrera / SC style engines, the way I see it you need three basic things to back date heat: 1. you need the two pressurized air ducts to pass through the engine tins. 2. you need pressurized ducts allowing cooling air to be routed into the two heat exchangers from the fan shroud. 3. you need back-dated heat exchangers (dual in, dual out style). Either early factory or SSI, DANSK, etc.

The early style parts that you would need are: (4 parts total) left and right tin adjacent to the flywheel side of the engine. left and right pass through tins (these small sheet metal parts allow the ducts to pass through the engine tin. They bolt up to the previously mentioned side tins and to the rear engine tin (cooling fan side of engine).

The pressurized air ducts off of the cooling fan shroud can be found here: http://www.rennlight.com/duct/
(2 totaL) Early metal parts may be available. The 930 part is necessary to clear the distributor, which is not an issue with various, early applications.

You also need the flexible ducting and hose clamps. I bought aero grade silicone impregnated ducting (high temp) at www.aircraftspruce.com

Hope that is helpful.

Doug

[Sumotang]

I think backdating the SC is a lot easier than the Carrera. I don't think you need to back-date the heat exchangers.

I think all you need are the updated pieces either side of the fan shroud. From these new pieces you just connect them up to each heat exchanger.



In the drawing it appears you need items 9, 10, 11, 12 and 13.

Can anyone confirm.

[76carrera3.2]

Originally posted by Sumotang
I think backdating the SC is a lot easier than the Carrera. I don't think you need to back-date the heat exchangers.

I think all you need are the updated pieces either side of the fan shroud. From these new pieces you just connect them up to each heat exchanger.



In the drawing it appears you need items 9, 10, 11, 12 and 13.

Can anyone confirm.

True but you also need the side tin, pieces 19, 20, 22, and 23.
Parts needed:
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

I just did this to my '84 engine. Be sure to try to get the 930 left duct so it will fit around the distributor.

[Sumotang]

Doesn't the SC already have the side tin pieces 19, 20, 22 and 23?

[wilke3169]

I have done this to an '81 and my present '79. The pieces 19, 20, 22, & 23 are already on the car. The drivers side unit is one piece. the passengers side unit is 2 pieces, a sheetmetal part and a plastic pass through scoop. The piece shown #13 is a blank that is used with normal heating when all of the air is ducted from the drivers side via the engine compartment blower.

[Kroggers]

I have a recollection about a thread where someone was making the backdate replacement parts (9,10,11 & 12) from Carbon Fibre, or had a supplier for them, but I can not find the thread at the moment??

[widebody911]

Originally posted by Kroggers
I have a recollection about a thread where someone was making the backdate replacement parts (9,10,11 & 12) from Carbon Fibre, or had a supplier for them, but I can not find the thread at the moment??

I make them in fiberglass or carbon fiber. I've sold quite a few in FQ but only a couple in CF because I have a hard time getting the cosmetics acceptable.

[Kroggers]

Thom, do you have any pics of the CF ones?

[Jeff Alton]

Click on the www at the bottom of all his posts.....

Cheers

[jcc911]

Thom, since you are the resident expert, could you please tell me what is needed for a 78SC? Do you have both sides in stock?

Did you ever get your garage cam back up and running?

Thanks, J.

[greglepore]

On a Carrera, you need only 1 (ONE) hard part-either Thom's duct or a John Walker modified duct (the early part doesn't clear the dizzy). A hose from there to the inlet to the h/e's that's already thru the tin feeds both h/e's and gives you plenty-o-heat. You don't need to mess w/ the heat exchangers or the right side duct.

[jcc911]

I should have mentioed that I already have SSIs

[jeff1hughes]

I hope not to sound foolish, but why backdate the heat system?

[RoninLB]

If it's not needed for stop and go window fogging or around town slow crusing heat it's not necessary imo.

[greglepore]

I hope not to sound foolish, but why backdate the heat system?

In my case, it was the desire to clean up the engine compartment for access and appearance. Many jobs required removal of the blower and duct at the outset.

[jcc911]

Removal of the blower and hoses is required inorder for the turbo plumbing to fit.
Also, it does remove a lot of "clutter."

[widebody911]

Originally posted by jcc911
Thom, since you are the resident expert, could you please tell me what is needed for a 78SC? Do you have both sides in stock?
I'm not really an expert in backdating, I just make the pieces. I've been meaning to put together a FAQ but haven't got around to it yet

Did you ever get your garage cam back up and running?

The CCD in the old camera died, and I'm afraid if I use my new one in the same manner, it will die, too. I think it's too warm up high where the camera was mounted, and it cooked it.