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Re: My '72 911T
Posted: Sun May 10, 2020 7:02 pm
by Gary71
Fingers crossed it will be ready. I think my metal working is now at the standard where I can work properly on areas and be happy with it, unfortunately this is probably the last bit I’m going to do
Like most skills you work it out just before you’ll never need it again.
Re: My '72 911T
Posted: Mon May 11, 2020 8:29 am
by hot66
Looking great Gary

Re: My '72 911T
Posted: Thu May 14, 2020 5:03 pm
by Gary71
Next project (outside of metal bashing) is to try and improve the ventilation a bit. It's not going to be Johnny's aircon by any stretch of the imagination, but even a 10% improvement in airflow would help those time when you are dying of heat exhaustion in the French countryside.
On the advice of our aircon expert the fan was the primary suspect for change. 60's tech and vintage bearings combined to make it pretty ineffective. I was looking at various borrowed systems from other cars and making a new box, but his suggestion was to use a small high performance intercooler fan within the original box.
24hrs later this little Spal fan turns up and it could have been made for the job! It sits beautifully in the hole left by the original fan with nothing more than some spacers to give a clearance to the backwall of the box.
I’ve not powered it up yet, so it may sound like a jet at take off, but I haven’t modified the original box at all (other than three 6mm holes) so all else fails I can put it back.
The other thing I’d like to do is work out how to duct some more air at face level. Not sure how yet but popping up the original speaker grill is the current favourite idea. Either that or remove the radio and put a rectangular vent behind a false cover.

Re: My '72 911T
Posted: Thu May 14, 2020 5:19 pm
by Bootsy
Ditch the clock and have a vent there? Seen it done a few times
Re: My '72 911T
Posted: Thu May 14, 2020 5:53 pm
by 911hillclimber
Indeed, the wife gets left out though, so that may not work totally...
Like the radio position idea as I have no radio (too much noise).
Caravan ducting fittings from Truma uses the same ducting diameter and there is a good range of T's, elbows etc.
Re: My '72 911T
Posted: Thu May 14, 2020 11:35 pm
by Nine One One
Gary71 wrote:Next project (outside of metal bashing) is to try and improve the ventilation a bit. It's not going to be Johnny's aircon by any stretch of the imagination, but even a 10% improvement in airflow would help those time when you are dying of heat exhaustion in the French countryside.
On the advice of our aircon expert the fan was the primary suspect for change. 60's tech and vintage bearings combined to make it pretty ineffective. I was looking at various borrowed systems from other cars and making a new box, but his suggestion was to use a small high performance intercooler fan within the original box.
24hrs later this little Spal fan turns up and it could have been made for the job! It sits beautifully in the hole left by the original fan with nothing more than some spacers to give a clearance to the backwall of the box.
I’ve not powered it up yet, so it may sound like a jet at take off, but I haven’t modified the original box at all (other than three 6mm holes) so all else fails I can put it back.
The other thing I’d like to do is work out how to duct some more air at face level. Not sure how yet but popping up the original speaker grill is the current favourite idea. Either that or remove the radio and put a rectangular vent behind a false cover.

Can you give some more details on the fan upgrade/model/size etc please
Re: My '72 911T
Posted: Thu May 14, 2020 11:46 pm
by 210bhp
911hillclimber wrote:Indeed, the wife gets left out though, so that may not work totally...
Like the radio position idea as I have no radio (too much noise).
Caravan ducting fittings from Truma uses the same ducting diameter and there is a good range of T's, elbows etc.
And if you can fit a duo-directional vane in the gap both of you can be happy.
Regards
Mike
Re: My '72 911T
Posted: Fri May 15, 2020 12:34 am
by Flat 6
Yes, more info and photos please, could become a standard mod.
My US '73T has most of the aircon kit in boxes and I may well try to reinstate it. It has the nifty under dash vents.
While working out what I need to reinstate the actual aircon I was going to set it up just as a fresh air supply. This fan may also work for that. The original was in the smugglers box but I couldn't really see how it was fed with fresh air. It did have the hole in the front slam panel and the windscreen washer bottle is relocated to the rear of the front compartment so I know there was once something behind the front panel, I think I've seen photos of a black box but haven't researched it properly.
Anyway, mentioning this because you could always source one of those under dash units and find a way of supplying it with fresh air. The vents run right across the car and are adjustable for both sides.
Al
Re: My '72 911T
Posted: Fri May 15, 2020 12:38 am
by Flat 6
AC+Under+Dash+Air+Plenum1272123781.jpg
Re: My '72 911T
Posted: Fri May 15, 2020 7:21 am
by Gary71
Let’s not too far ahead of ourselves, I don’t want everyone running out buying fans when I’ve not checked it: makes it any better/blows the wrong way/doesn’t catch fire/shake the box to bits/cause a small vacuum based black hole.
However it’s this:

Bought from this seller:
For obvious reasons I can’t check it in installed in the car, but I’ve charged a battery overnight so will run it up on the bench this afternoon and try to measure the airflow difference (if any!) using my carb flow meter or something.
Vents wise I don’t want to add the underdash ones as they are frankly hideous

Subtle is name of the game, however subtle vents also means less effective so there’s a balance.
The problem with the vent is how to get the air to it, there’s not much space back there. I need to find out how the later cars do it.
For the vent itself something like this hidden under a false front in place of the radio will do.

Re: My '72 911T
Posted: Fri May 15, 2020 10:10 am
by hot66
on the fan .. I found just replacing the fan with a new OEM one worked brilliantly
Re: My '72 911T
Posted: Fri May 15, 2020 10:27 am
by Gary71
hot66 wrote:on the fan .. I found just replacing the fan with a new OEM one worked brilliantly
Where's the fun in that

Re: My '72 911T
Posted: Fri May 15, 2020 2:43 pm
by sladey
I'll be interested to hear of your progress on the fan Gary
Re: My '72 911T
Posted: Sat May 23, 2020 4:53 pm
by Gary71
Afternoon. Well the fan fits and it blows a lot of air and isn’t too noisy, no idea if it’s any good! I’ve also bought a 60mm Y piece and some hose to duct it to the dash somewhere. That’s going to need a bit more thought without cutting the obvious hole like a later car!
A little more metal work today finishing the wing support by moving the fixings on the somewhat inaccurate Restoration Design panel. They taken the feedback and are changing their part
I located a set of early hinges in darkest Germany and have now fitted them with my original bolts (no big washers!).
I just need to find the other 6 in a bag somewhere...
The door check pin holes are oval on both sides which means you get a lovely ‘crack-bang’ noise at each spring stop on the check arm.
Any ideas how to make them round again? Access is miserable for the obvious weld them up and drill them.
Cut them off just at the back of hole and make new and weld them on is one slightly scary idea I’ve had.
Re: My '72 911T
Posted: Sat May 23, 2020 5:01 pm
by 911hillclimber
Strap holes:
I've been plagued with the crack for 30 years. I think the yoke in the A post is hardened to make things harder still...
Partially and nearly fixed it by putting a high tensile bolt in there, M6, and pinched the lot using a nyloc to give a drag and they are quiet. Doors close easy.
If and when the friction eases, nip it a bit tighter.
The shoulder of the bolt just gives that slightly larger diameter where it's needed.
Just a thought that worked on mine.
G.