• We have upgraded our forum software! See here for details.

Old Air A/C-Heater

Fahrbach 1951 3600

Fahrbach 1951 3600

Member
Joined
Jun 15, 2016
Messages
14
Reaction score
3
Age
75
I'm starting to think about adding A/C. These Kansas high temps make it a hard sell to get my wife out for an evening stroll. I'm not a fan of the units that mount along the contour of the bottom of the dash, and would really like to know more about the Old Air units that vent the air through the radio speaker grill. I'm really curious to hear from anyone who has installed that unit and how they would rate it. Any help appreciated.
 
I used one in a 51 GMC that was well insulated and it did the job. Since the air just comes straight out of the grill I did fab up a deflector which attached to the radio grill bars to route the air to the drivers side. With the a/c going full blast on a triple digit day the metal speaker grill sweated enough for condensate to drip on the carpet. Old Air units are made in the USA and every bit as good as Vintage and in some applications are better.
 
As someone who is skeptical of everything new, can you explain in detail (or relatively) what changes to the firewall, under the dash, like does it interfere with the electric wipers, etc, etc, and what are you doing with the engine (2nd pulley on the HB?) etc. I can fabricate anything, but metal work on a brand new paint job could be problematic. Does the existing stock radiator need to be upgraded? What does Old Air and Vintage Air NOT tell you? Thanks!
 
Deve said:
As someone who is skeptical of everything new, can you explain in detail (or relatively) what changes to the firewall, under the dash, like does it interfere with the electric wipers, etc, etc, and what are you doing with the engine (2nd pulley on the HB?) etc. I can fabricate anything, but metal work on a brand new paint job could be problematic. Does the existing stock radiator need to be upgraded? What does Old Air and Vintage Air NOT tell you? Thanks!
Click to expand...


Most of these kits mount the compressor with a 2 groove clutch pulley where the generator originally was. They keep the original water pump and balancer pulleys and drive the A/C compressor with a single belt. The 2nd groove on the compressor pulley drives an alternator that mounts above the compressor. The trick is that the A/C compressor wants a 3/8" belt. Most of the GMC water pump and balancer pulleys are not 3/8". I found that a 13 mm wide belt will just barely stay out of the bottom of the 5/8" pulleys on my engine. It rides a little high in the A/C clutch pulley with the outer surface of the belt about 1/8" proud of the pulley. Benn running it that way for a few months now and it has yet to throw a belt. Not exactly a high RPM application.
 
That is interesting, Bill. With the AC compressor driven by one v-belt only, and also the load of the alt. on it, does the belt ever slip when the AC cycles?
Does your cab stay plenty cold in Texas heat?

Deve, from what I have researched, the Vintage Air kit mounts to existing heater mounting holes. The AC and heater hoses go in through a 4-hole bulkhead fitting that fills the vacant heater motor hole. You will remove everything original, and the kit supplies everything you need. They even include a cover for the engine side of the firewall, to dress up where you removed that ugly copper heat control valve.

Steve.
 
Ok guys,
Lets make this thread WORK for us. Would it be possible for any of you who have A/C in your trucks to snap some photos of the install, engine bay and interior, with brand name of product used? Straight 6, V8, doesn't matter. Tell us the good and bad with your install. Thanks in advance!
 
50 Chevy LS3 said:
That is interesting, Bill. With the AC compressor driven by one v-belt only, and also the load of the alt. on it, does the belt ever slip when the AC cycles? Does your cab stay plenty cold in Texas heat?
Click to expand...

The shop that installed the A/C for the previous owner of my truck used a belt that measured 0.47" across the top of the V to go around the crank, water pump and A/C pulleys. It ran in the bottom of the crank and water pump pulleys, without making proper contact with the sides of the V. The belt would slip (squeal) every now and then when first turned on, especially if the engine was at speed (driving down the road) and then turning on the A/C. I replaced the belt with one that measured 0.51" across the top of the V. It does not ride on the bottom of the pulleys and no more squeal.

Takes a while to cool down my uninsulated cab with dark paint, but eventually gets there.

My Vintage Air unit has the ability to direct output air flow to the windshield, dash vents, floor vent or combo dash and floor. If the floor vent is selected with a high fan setting, A/C on and a hot muggy day (typical of Houston from May through September) some of the condensed water that should exit the evaporator case via the drain hose ends up spitting out through the floor vent.
 
Last edited:
You can order the Sanden a/c compressor with different pulleys from 3/8 up to 3/4 for use on a flathead Ford. A generator pulley will bolt right on an alternator so just use your old generator pulley. Google 216/235 a-c compressor bracket and scroll down to pictures to see mounting. Picture (orange truck) of the Vintage under hood a/c and heater hose routing and interior air plenum/outlets/ controls. Picture of (blue) GMC radio grill air outlet (shows nothing but guess that's the idea). The Old Air Products unit lets one keep the full glove box yet is more tucked up under the dash and plenum/ outlets more closely follow bottom of dash contour. No interference with wipers or defroster ducts.

dan's 49 011.jpg dan's 49 010.jpg 51 GMC 007.jpg
 
Just remembered another design which Lucky's out of Ennis, Texas sells. It just has a diffuser on both ends of the dash and one in the middle instead of a plenum across the entire bottom (red truck). If I am starting from scratch and have no paint to worry about The VERY BEST a/c for old cars or trucks is an under dash unit mounted up in the dash. No hoses, cables, valves, relays, vacuum hoses, ducts, and so on. Just turn on the switch and get INSTANT cold (yellow car).

019.JPG Mike's 39 005.jpg
 
There is a photo of my 235 with the Old Air set up in my "media" on this site. I do not know how to move the picture from the file to this message. The photo was taken with the engine set up, but no front sheet metal.
Jim. :)
 
Personally, I would like to use the radio area ventage to disperse the cool with maybe another angled hidden hose pointing downward and out on the sides somehow. That is not the real concern for me, the main concern is how much fabrication and cutting into the firewall is there? Condenser (radiator) location, how to make this the least obtrusive addition. Also, is it REALLY preferred to run a dual pulley off another location other than the HB? I do not have an argumentative bone in my body, so please understand I am HONESTLY trying to find the perfect AD solution so I can write an extensive How-T0 that meets as many peoples requirements as possible. We need that! I hope the OP (original poster) is in total agreement? How to NOT display out in plain site that it has very good, very efficient air conditioning. (Not that I am not VERY appreciative of another avenue that looks very professional (Jim).
 
Deve, you know, really, if your gonna be a purist, livin' in the '50s, kind of guy...
It's windows down, vents open, shirt off...:D

Steve.
 
Bill and Steve,
Thanks for moving my old photos from the gallery. The picture Steve posted of the engine and AC set up is the photo I had in mind. The interior pic shows the AC plenum under the 54 dash.
My truck was completed in 2003 (three years in the remake).
Engines don't remain pretty very long once headed down the road.

Jim
 
Absolutely ZERO cutting of the firewall. There is a plate that fits over the hole where the heater motor used to stick through the firewall that has four bulkhead fittings in it, two for a/c hoses and two for heater hoses. How you do the inside components is up to you but it some times takes a hole or two in the bottom dash lip which are hidden from sight and sometimes a bolt near the top of the firewall for a rear brace on the evaporator unit. If you use an oval head bolt it looks factory. Don't over think this job, it's pretty straight forward with no complex tasks. The guys in the shop usually take a half day to mount everything, inside and out, and then leave the vacuum pump going during lunch break so it can be charged with 134 when they get back. On orphan vehicles like my 37 Buick or a customers 38 Studebaker it may take several days since all brackets, hoses, wiring, etc. has to be made from scratch but on a Chevy or Ford they have the kits down just about pat. A long time friend with no experience and never owned tools put one in a 52 in about three days. He's a retired flour salesman but with access to our tools and coaching he chugged right along.
 
A second v-belt groove on the crank pulley would be so much better. This design is poor, and only working because of the low rpm's of the Chevy sixes.
I'm thinking with this single belt driving the fan/water pump, Alt., A.C. compressor, one would be constantly replacing the belt. That is, if these trucks were driven very many miles a year.
Low rpm heavy duty diesel engines either use matched v-belts, or multi-groove belts, with belt tensioners. And even those slip at times. especially if one's radiator becomes the slightest bit restricted with dirt, bugs, etc.
The load transmitted to the drive belt, at modern highway speed/RPM, when the A.C. compressor cycles, is tremendous.
Tightening a single v-belt up like a banjo string will ruin bearings.
I knew a guy many years ago that over tightened his twin v-belts, on a 8V71 Detroit Diesel, and broke the nose of his crankshaft off.

Steve.
 
50 Chevy LS3 said:
A second v-belt groove on the crank pulley would be so much better. This design is poor, and only working because of the low rpm's of the Chevy sixes.
I'm thinking with this single belt driving the fan/water pump, Alt., A.C. compressor, one would be constantly replacing the belt. That is, if these trucks were driven very many miles a year.
Low rpm heavy duty diesel engines either use matched v-belts, or multi-groove belts, with belt tensioners. And even those slip at times. especially if one's radiator becomes the slightest bit restricted with dirt, bugs, etc.
The load transmitted to the drive belt, at modern highway speed/RPM, when the A.C. compressor cycles, is tremendous.
Tightening a single v-belt up like a banjo string will ruin bearings.
I knew a guy many years ago that over tightened his twin v-belts, on a 8V71 Detroit Diesel, and broke the nose of his crankshaft off.

Steve.
Click to expand...
3+ years and about 12,000 miles on mine with this "poor" design. No belt problems.
 
I think both of you have a point. No way would I use on a high rpm engine but my 37 Buick has worked fine for the last 30 years with just ONE belt. Has TENS of thousands of miles and just one belt change and that was when I had the front clip off and changed it while it was easy to do. I was very concerned with the small amount of belt wrap on the water pump pulley so it has an electric fan that has never been turned on. It's geared so 2100 rpm is 63 mph and that is probably why it works. We also have a 69 high winding Z28 in that we just converted to a serpentine system because it throws belts. Could have gone to Corvette deep groove pulleys and guide bearings but serpentine looks much cleaner. Pic of Buick.



Straight 8 a-c mount 001.jpg
 
Bill Hanlon said:
3+ years and about 12,000 miles on mine with this "poor" design. No belt problems.
Click to expand...

Ok, Bill, the term, "poor", was a bad choice. Insert, "This design could be much improved upon". And, no sense trying to fix what aint broke.

I keep thinking in terms of vehicles that run 350,00-400,000 miles in 3 years. Can't snap out of it...
Also, modern multi-grooves give so much more "traction". But, this site is mostly for those who like old-timey.

Steve.
 
You must log in or register to reply here.
Back
Top