Firewall for Factory A/C
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,793
Likes: 58
From: God's Country The Old Dominion
Firewall for Factory A/C
I have been struggling with the heater core on what I thought was a factory a/c 1968 roadster. Everything in the engine compartment looked factory however I found several things that lead me to believe the a/c was added later. The first was that the hole for the wiring harness was too small to get the connectors through. No biggie...I opened it up. My latest issue has been the core. When I removed the a/c box to install the correct switch on top I thought I would replace the heater core while I was in there. Several of the screws on top and on the right attaching the box to the firewall were unusually long. Upon reinstall I noticed the right side of the box sits about 3/4" off the inside of the firewall. The picture is the inside view of the opening in the firewall. The core pipe hit the casing on the other side of the firewall. See the attached picture. Does this look correct? I don't know what it is supposed to look like. Thanks
Last edited by Too Slow '90; Jan 27, 2015 at 07:57 PM.
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,793
Likes: 58
From: God's Country The Old Dominion
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
here is a original 69 firewall with AC, for your reference;
tons of detailed pics here: http://sspinball.com/SSGarage/SSCorv...s_corvette.htm
tons of detailed pics here: http://sspinball.com/SSGarage/SSCorv...s_corvette.htm
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,793
Likes: 58
From: God's Country The Old Dominion
here is a original 69 firewall with AC, for your reference;
tons of detailed pics here: http://sspinball.com/SSGarage/SSCorv...s_corvette.htm
tons of detailed pics here: http://sspinball.com/SSGarage/SSCorv...s_corvette.htm
Race Director
Joined: Oct 2000
Posts: 12,681
Likes: 3,134
From: Shamong, NJ
I'm going to say that the hole in your firewall, looks to be pretty crudely cut to me. I know that 68's were a learning experience for GM, and the build quality wasn't all that good, but that doesn't look like the factory hole to me.
I have a clip from a 75 AC car at the shop, and the hole's cut much cleaner than the one in your car. I'll get a couple pictures later, and post them.
Even if the hole is cut right, it's no guarantee that the heater core you have coming will fit right. The tubes on the AC cores are often an issue. The tubes almost always need a little "adjustment", to get them to fit. It doesn't seem to make much difference if it's an original Delco cores, an aftermarket US made one, or a replacement from Mexico or Taiwan, the tubes never seem to be positioned exactly right.
I have a clip from a 75 AC car at the shop, and the hole's cut much cleaner than the one in your car. I'll get a couple pictures later, and post them.
Even if the hole is cut right, it's no guarantee that the heater core you have coming will fit right. The tubes on the AC cores are often an issue. The tubes almost always need a little "adjustment", to get them to fit. It doesn't seem to make much difference if it's an original Delco cores, an aftermarket US made one, or a replacement from Mexico or Taiwan, the tubes never seem to be positioned exactly right.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Might have been a sabre saw. At the front of the AIM there is page showing how the stock heater core firewall hole had to be opened larger for the optional factory air. If memory serves, the page says the cut made on the assembly line was supposed to have been "neat." Wishful thinking.
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,793
Likes: 58
From: God's Country The Old Dominion
I'm going to say that the hole in your firewall, looks to be pretty crudely cut to me. I know that 68's were a learning experience for GM, and the build quality wasn't all that good, but that doesn't look like the factory hole to me.
I have a clip from a 75 AC car at the shop, and the hole's cut much cleaner than the one in your car. I'll get a couple pictures later, and post them.
Even if the hole is cut right, it's no guarantee that the heater core you have coming will fit right. The tubes on the AC cores are often an issue. The tubes almost always need a little "adjustment", to get them to fit. It doesn't seem to make much difference if it's an original Delco cores, an aftermarket US made one, or a replacement from Mexico or Taiwan, the tubes never seem to be positioned exactly right.
I have a clip from a 75 AC car at the shop, and the hole's cut much cleaner than the one in your car. I'll get a couple pictures later, and post them.
Even if the hole is cut right, it's no guarantee that the heater core you have coming will fit right. The tubes on the AC cores are often an issue. The tubes almost always need a little "adjustment", to get them to fit. It doesn't seem to make much difference if it's an original Delco cores, an aftermarket US made one, or a replacement from Mexico or Taiwan, the tubes never seem to be positioned exactly right.
Last edited by Too Slow '90; Jan 29, 2015 at 08:11 PM.
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Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,793
Likes: 58
From: God's Country The Old Dominion
Might have been a sabre saw. At the front of the AIM there is page showing how the stock heater core firewall hole had to be opened larger for the optional factory air. If memory serves, the page says the cut made on the assembly line was supposed to have been "neat." Wishful thinking.
Platinum Supporting Vendor
Joined: Sep 2001
Posts: 3,665
Likes: 341
Race Director
Joined: Oct 2000
Posts: 12,681
Likes: 3,134
From: Shamong, NJ
The pictures below are of a 75 factory air car. The first picture is looking at the firewall, from inside the car, and the second picture is from the engine side of the firewall.
Compare the shape of the recess on the right bottom side of the opening in my first picture, to that same recess in your firewall. The factory cut has a smooth flat bottom, while the recess in your firewall is rough and curved. Actually, you can see that the edges of the opening in your firewall, are very rough all the way around, while the edges of the opening in the 75 firewall, are crisp and smooth.
I'd say that someone has converted your car to factory air. This is not a bad thing, though you may want to use my pictures to clean up the opening in your firewall a little, before you put it all back together.
Out of curiosity, what does the air vent above your center gauge cluster look like? 68's have a unique, one piece vent. 69 and later AC cars used a two piece center vent.
Compare the shape of the recess on the right bottom side of the opening in my first picture, to that same recess in your firewall. The factory cut has a smooth flat bottom, while the recess in your firewall is rough and curved. Actually, you can see that the edges of the opening in your firewall, are very rough all the way around, while the edges of the opening in the 75 firewall, are crisp and smooth.
I'd say that someone has converted your car to factory air. This is not a bad thing, though you may want to use my pictures to clean up the opening in your firewall a little, before you put it all back together.
Out of curiosity, what does the air vent above your center gauge cluster look like? 68's have a unique, one piece vent. 69 and later AC cars used a two piece center vent.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
You might need to do a bit more trimming to get the heater box and heater core to go in ...and that is just by me comparing the other photos provided.
Hopefully your heater core tubes ate soldered in well....and as you know...do not use excessive force installing the heater box.
DUB
Hopefully your heater core tubes ate soldered in well....and as you know...do not use excessive force installing the heater box.
DUB
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,793
Likes: 58
From: God's Country The Old Dominion
The pictures below are of a 75 factory air car. The first picture is looking at the firewall, from inside the car, and the second picture is from the engine side of the firewall.
Compare the shape of the recess on the right bottom side of the opening in my first picture, to that same recess in your firewall. The factory cut has a smooth flat bottom, while the recess in your firewall is rough and curved. Actually, you can see that the edges of the opening in your firewall, are very rough all the way around, while the edges of the opening in the 75 firewall, are crisp and smooth.
I'd say that someone has converted your car to factory air. This is not a bad thing, though you may want to use my pictures to clean up the opening in your firewall a little, before you put it all back together.
Out of curiosity, what does the air vent above your center gauge cluster look like? 68's have a unique, one piece vent. 69 and later AC cars used a two piece center vent.
Compare the shape of the recess on the right bottom side of the opening in my first picture, to that same recess in your firewall. The factory cut has a smooth flat bottom, while the recess in your firewall is rough and curved. Actually, you can see that the edges of the opening in your firewall, are very rough all the way around, while the edges of the opening in the 75 firewall, are crisp and smooth.
I'd say that someone has converted your car to factory air. This is not a bad thing, though you may want to use my pictures to clean up the opening in your firewall a little, before you put it all back together.
Out of curiosity, what does the air vent above your center gauge cluster look like? 68's have a unique, one piece vent. 69 and later AC cars used a two piece center vent.
The vent is the later model two piece. I searched for a correct one but just like the 4-speed console plate they are not cheap. The controller is also incorrect but it should work.
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,793
Likes: 58
From: God's Country The Old Dominion
You might need to do a bit more trimming to get the heater box and heater core to go in ...and that is just by me comparing the other photos provided.
Hopefully your heater core tubes ate soldered in well....and as you know...do not use excessive force installing the heater box.
DUB
Hopefully your heater core tubes ate soldered in well....and as you know...do not use excessive force installing the heater box.
DUB