Backdated heat and A/C.........

[fred cook]

Can air conditioning be used on an engine that has had the heat backdate done on it? I am getting ready to build and engine for my SC and would like to do the heat backdate AND keep the a/c.

Thanks,

[Flat Six]

IIRC, most heater backdate involves:

1) Removing the engine-mounted auxiliary blower, and relying on only the footwell blowers instead.

2) Also may involve introducing additional resistance in the footwell blower circuit (formerly supplied by the now-removed engine bay blower) to make sure the FW blowers operate correctly.

3) Changing the air duct on the driver side (LHD) of the engine fan to direct more air over the driver-side bank of cylinders.

4) May also involve (depending on HEs installed, model year, etc.) re-routing/replacing hot-air hoses.

All of this is independent of the AC system, so I don't see any reason why you can't do both. But not having done it myself, perhaps someone who has done it can chime in with some helpful hints for you?

Good luck Fred. HTH

Dale

[Neel]

^+1..

[KNS]

I had a 1980 SC that I backdated the heat - so glad I did. The AC will work just fine without the extra heating bits...

[tcar]

The A/C and the heating system on the 911 SC and earlier are totally separate. Ditto thru '89.

Neither affects the other.

You can totally remove the heating system and keep the A/C (and vice-versa).

He11, the ventilation system is almost separate too.

Integration? Nah.

[fred cook]

What I was concerned about was fitting the right side hose under the a/c mounting bracket. I had read somewhere that the block off plate tube on the passenger side would interfere with the a/c mount.

[Bob Kontak]

I got the piece from PP and had no problems fitting it. Went right under the AC bracket on my 81. It's been a while - maybe a tap or two with a hammer to make clearance. The driver's side from PP was the PITA. I thought it would be the reverse like you. Search on posts - some say the driver's side fits great. Not my experience.

[Bob Kontak]

Originally Posted by Flat Six

2) Also may involve introducing additional resistance in the footwell blower circuit (formerly supplied by the now-removed engine bay blower) to make sure the FW blowers operate correctly.

Does the 83 have footwell blowers?

[schumicat]

no, I believe that started in 84 with the Carrera.

Originally Posted by Bob Kontak

Does the 83 have footwell blowers?

[Bob Kontak]

Thanks

[D911SC]

Originally Posted by Bob Kontak

Does the 83 have footwell blowers?

Don't think so. Mine certainly doesn't. I thought these came in 84-

EDIT - beat me to it schumicat!

[JJ 911SC]

Originally Posted by D911SC

Don't think so. Mine certainly doesn't. I thought these came in 84-

EDIT - beat me to it schumicat!

No blower for sure...

I just finished the heat backdate after I put the SSI. My AC is already deleted so I can not speak of the right side but even without putting my distributor on, I know that the left side will need some convincing as in beeing ballpeened as per Bob finding.

Extrack from; SSI Heat Option

... Moving right along as fast as a

With the help of DW SD (post 52 of Why you should backdate your heat on a 3.2) I converted the side tin to allow the hose to go through.

I bought the 2 holed square pieces, overlap them on the original side pieces. Mark where to cut and drilled, did a "fast" paint job, installed the hose and voilas;

Still have to installed some nice looking hose clamp.

[Canada Kev]

Looks great. Where did you get the holed square pieces?

[JJ 911SC]

Originally Posted by syzygy

Looks great. Where did you get the holed square pieces?

Thanks. On PP used part forum while doing a search for "engine tin". Came all the way from Hawaii.

I'll check with someone else that show me a picture that had then on it (not sure if they were for sale) and I'll let you know.