Tips & adivce needed for backdating heat

[michael lang]

I am finally at a point where I am ready to put this thing back together 3.2l rebuild, the quest for more power and one of the things that was on my "want" list was to backdate the heat. I really like the way it makes a 911 engine look and having heat was one thing I wasn't willing to compromise on. So I go to the search function and start looking at various things that guys have done. Ideally, I'd like to replace the engine tin to do a correct backdate if for any reason because I believe the heat works the most efficiently in that configuration but I have seen a lot of engines that do not go that route and use the existing engine tin and snake a single tube around the distributor through the heater ducting hole in the back tin panel. How good does the air get pushed to the heat exchangers that way? Also, what I haven't been able to find is how the tubing goes to the right side heat exchanger. Or, does it not work like that and just goes thought a hole that has to be cut on the right side tin?
In doing my search I see there are threads that show the ducting that comes off the left and right sides of the fan shroud but when I do my search for the part, I can only find the left side. Does that mean that I will be using the existing right side duct panel to guide the air to the right side exchanger? Would you guys please post some pics of what you've done in your backdating of your heating and what parts you used to do that? Both ways would be preferential. If there was something that you came across while doing the conversion that you now think "If I had to do it over again I'd do it ..." what would that be?
Any other tips or advice that you guys could offer would be greatly appreciated, I'm trying to do my rebuild very proudly and have this board to thank for all that I have learned along the way.

[JJ 911SC]

Mike,

I went the old way for the clean look, straight path to the SSI's.

I bought the 2 "holed" pieces and fitted them to the side engine tin pieces.

[DaveMcKenz]

No distributor is kind of cheating.
Dave

[JJ 911SC]

Originally Posted by DaveMcKenz

No distributor is kind of cheating.
Dave

I use to have one... and it fit.

[911pcars]

This thread may help:
Ssi in 3.2 parts questions

Sherwood

[wildcat077]

Mike,

I have a nice zinc plated L/H side heater backdate shroud for sale in the classifieds ... it fit perfectly with no interference to the distributor !
By the way,i didn't need the right hand side ducting on my 89 3.2 ...

Cheers
Phil

[wildcat077]

Here you go ... JJ saw it in my car when it still had a 3.2 in it !

[JJ 911SC]

Originally Posted by wildcat077

Here you go ... JJ saw it in my car when it still had a 3.2 in it...

Yeah per, the good old days before the insanity set in

[Sicklyscott]

I'm assuming the 3.0 and 3.2 parts are the same?

[gliding_serpent]

I am copying JJ. Searcing on the topic will repeatedly bring you to his posts and photos... For a good reason.

Also, spend the extra $$ and get the 930 turbo air duct from the fan shroud on the drivers side. It will clear the distributer properly. The more generic piece many link to in your searches requires "extensive massaging."

[DaveMcKenz]

Originally Posted by JJ 911SC

I use to have one... and it fit.

Sorry, I didn't see it. I needed the turbo version of the left side air duct, in order to clear the distributor.
Dave

[sugarwood]

Is backdating the heat just an aesthetic preference?
Or does it work better than the 80's heating system?

[gliding_serpent]

Is backdating the heat just an aesthetic preference?

Or does it work better than the 80's heating system?

I will let you know how it works this spring... But word is that at high rpm, it works almost too well. Want more heat? Drive faster. ;-)

I think the benefit comes less from weight loss, and more from a loss of plastic, and a gain of accessability in the engine bay. To me, that makes it appealing to the diy guy. The gained access is huge. Plus, asthetically i would rather see the intake plenums than a plastic tower. I am not a fan of plastic fantastic that is so common in modern cars.

However, if you drive in stop-start traffic in the cold, or your car is oem concourse, a heat backdate is not a great idea.

[DaveMcKenz]

Originally Posted by sugarwood

Is backdating the heat just an aesthetic preference?
Or does it work better than the 80's heating system?

It is pretty much needed if you go with SSI heat exchangers, which are copies of pre-74 units. That's how I went down that path. My P.O. did not do that. He used the engine mounter blower to send air to the driver's side only. Nothing was attached to the right side. No cross-over pipe. I could have just added a right side duct, but I wanted to clean up the left side by removing the engine blower motor and ducting.
So it started functional, and ended esthetic. I don't think it works any better than stock, and probably not as well at low rpm's. The engine mounted electric blower was an improvement.
Dave

[SpyderMike]

I am almost done backdating my heat in my 1985. I bought the 930 duct from Pelican P/N 930.106.321.02 and it doesn't quite fit. It clears the distributor fine, but it interferes with the oil line to the cam chain tensioner on the right hand side. The end of the tube to which the duct with attach is hitting the oil line and can't sit down the final 1/4" it need to line up properly with clearance so that I can attach the duct down to the cross over pipe. To me this has been the only hurdle in backdating the heat. Does anyone have any suggestions?

Is that plastic version of the side tin available anymore? t looks like it routes higher and more forward that the 930 part.

[Tremelune]

Backdating the heat (removing the engine blower) does not improve heat in the cabin, it simply cleans the look of the engine bay up and makes certain things easier to get to. If your car doesn't see bad weather, my understanding is that it will probably be enough. If you ever drive in rain you will want some blower for defrost (be it engine or footwell). You might be able to use the fresh air blower for that, I dunno.

[michael lang]

Sherwood, based on the parts diagram in your link, I should be getting parts 5 & 6 along with 14-18. Then I'll need some aircraft quality tubing and I should be good, yes?

Phil, if you didn't need the right side duct, what did you do? Leave it unattached and plug the opening on the heat exchanger?

[JJ 911SC]

Originally Posted by michael lang

... I should be getting parts 5 & 6 along with 14-18. Then I'll need some aircraft quality tubing and I should be good, yes?...

5, 6, 17, 18 and cut to suit 14 & 15.

SCEET AIRCRAFT DUCTING from Aircraft Spruce

Normal Left/Rear/Right pieces



Left Piece Overlay For Marking



Right Piece Overlay For Marking



Left/Rear Pieces Showing The Pre SSIs Heating Hose Hole



The Almost Finish Product (Missing The Ring To Hold The Hose). The PCA Crest Covers The Hole Perfectly.

[michael lang]

JJ, what's to say I couldn't just cut a hole in the end of panels 14 & 15 for the tubing, or is there something special about those end pieces that require them to be used? I noticed you used them as a template on where to cut off the ends of the side panels and attached the holed ends to the back splash plate. Has your PCA sticker punctured or torn yet? Or did you put something under there before attaching the sticker?

[JJ 911SC]

Originally Posted by michael lang

JJ, what's to say I couldn't just cut a hole in the end of panels 14 & 15 for the tubing, or is there something special about those end pieces that require them to be used? I noticed you used them as a template on where to cut off the ends of the side panels and attached the holed ends to the back splash plate. Has your PCA sticker punctured or torn yet? Or did you put something under there before attaching the sticker?

The side pieces are not flat so its a bit tricky to cut a hole but doable with a hole saw kit.

Its a PCA badge, fit perfectly.