: Convert a/c to non a/c
Mar 7th, 03, 10:59 PM
I want to remove the A/C box from my engine compartment. My compressor and condenser are long gone, so I'm going to get rid of the rest of the under-hood components to free up some space.
I've got the front clip off right now, so now would be a good time.
Does anyone have any tips or suggestions on procedure or what I might need?
(I posted this question a few weeks ago in a different forum, just thought I'de try it again here where it belongs)
Mar 10th, 03, 02:51 AM
kwik 69, i welded a 20 gauge sheet metal on the back side of the heater box opening and smoothed it with body filler. i also welded a cover over the hole for the blower. you will have to replace your kick panels with non air kick panels for ventilation. jack
Mar 11th, 03, 03:26 AM
So you did away with the heater?
I'de like to keep my heat/defrost functions. I didn't know if I could just buy a heater core case cover to fit as a non-a/c car, and then patch the remaining hole above. :confused:
Mar 11th, 03, 03:46 AM
Don't do it. The wiring and ventilation systems on an A/C car are so different that it will be a major effort to swapp all the peices. If you really wat to get rid of the Suitcase, just cut it down so that it is the same height as the little skinny section between the blower and the large section, glass over the opening. Drill a hole for the blower motor resistor and leave the rest of it alone.
An A/C car has no way to bring fresh air into the upper vents (the two on the dash). In a normal car these connect to two 3" diameter holes in the cowl area and have shutoff valves controlled by sliders on the kick panel. A/C cars don't have this feature, and if you start putting the complete non Ac system into the car, then the upper dash vents become useless. Theres numerous electrical changes you need to make, along with the control head, new kcick panels, etc. Major pain in the butt.
You will affect the future value of your car by doing anything more than cutting down the suitcase. It's hard to find a complete suitcase, but it's better than making sheet metal changes to the car.
Mar 11th, 03, 05:37 AM
kwik69, mark is correct in his post. when i removed my factory heat/air, i wanted to clean up my fire wall. i had a lot of parts missing, also. i plan on installing an after market behind the dash street rod type heat and air unit. Jack
Apr 13th, 03, 05:11 PM
For now, I'm going to chop the evap box down and bolt it back on.
Does anyone have any recommendations on HOW to "glass" a new top on it? Should I start with some sheet metal and smooth it with fiberglass filler?
In the future when my budget allows, I intend to add a vintage air unit under the dash.
Apr 14th, 03, 05:12 AM
I don't know why you would want to remove an original A/C system and replace it later with an aftermarket system, but it's you car. The original system works just fine, and the only downside is that it takes up a lot of space in the engine compartment.
But if you want to cut down the evaporator box I think I would remove the whole thing (means pulling the passenger fender and possibly the exhaust system on the passenger side). Split the case in half (if you didn't do that to get it out)Then pull out the evaporator. Find a point on the fenderside where it looks like it could be cut flush with the skinny section between the evaporator section and the fan section but dont cut is so far back that the two rear most screws that hold the case halves together get removed. Then bolt the other half back on and cut it donw level with the first cut you made. I think it would be easier to work with a thin fiber board as a backer than a piece of sheetmetal. Cut a peice that will fit inside the opening in the case that you just made and hold it inplace with some small wood screws through the side of the case. Glass over the board and wrap it down the sides but don't cover the screws. When that sets up remove the screws and then finish glassing over the board. You should also put a layer or two on the inside as well as this will make it stronger. Note that you will no longer be able to break the case in two pieces when you are done, so make sure you can get it back into the car without pulling a head if the engine is in the car. If there is enough room on the top of the case leave your blower motor resistor and fan relay where they are, otherwise if you have to move them, make sure the wires will reach as the pigtails on the connectors are not very long. You can cut the wires to the low temperature switch since the compressor is gone, but make sure you leave the fan power connector and ground wire intact.
Apr 14th, 03, 06:34 AM
Thanks again, Mark.
Is fiberboard same as cardboard? If not, where do you get it?
The only remnant of the existing a/c unit is the evaporator and evap box, everything else is gone and wiring is chopped to all but the blower motor. The evap box has a hole in it near the header which allows MEGA heat in...
One of my goals is to free up some engine compartment room. I specifically searched for a 69 w/o air...but you take what you can get. LOL
All of front end is removed at this point to paint the subframe & firewall. The evap box is on the work bench ready for cleaning & surgery.
After looking at it all and seeing how it all goes together, I think you are right in your assessment on an economical way to achieve the conversion. Thanks again for passing on the wisdom. graemlins/thumbsup.gif
Apr 14th, 03, 06:47 AM
my deal is different, someone hacked my firewall up prevously to me purchasing the car. they added factory style air out of a donor car. I'm installing a big block and was gonna run a vintage air setup to save space, now i've decided to switch back to a non AC, Big Block setup. I intend to clean up the firewall, the wiring i have is for non ac. My question is are the inside section of suitcase the same for small or big block???
Apr 14th, 03, 06:56 AM
Speaking of holes.... there is a 1" diameter hole in the very lowest point of the evap box as shown in the above pic that has a clip-ring and a few particles of dry-rotted rubber or hose around it.
What was this hole for (condensation drain maybe?)and is it NOW needed or can it now be filled?
Apr 14th, 03, 08:33 AM
Yep, that's a drain for the condensation, no AC, no drain needed
Apr 14th, 03, 10:11 AM
Fiberboard is a high density cardboard product. It is fairly rigid, and lightweight sort of like particle board, but it doesn't have any big chunks in it. Sometimes it is call MDF (Medium Density Fiberboard) places like home Depot carry it in 2' by 2' or 2' by 4' sections in their plywood aisle. You can get anything from 1/8" to about 1/2" thick pieces for anywhere between $2 and $8. 1/8" is more than enough for this application.
Originally posted by 68ragtop:
my deal is different, someone hacked my firewall up prevously to me purchasing the car. they added factory style air out of a donor car. I'm installing a big block and was gonna run a vintage air setup to save space, now i've decided to switch back to a non AC, Big Block setup. I intend to clean up the firewall, the wiring i have is for non ac. My question is are the inside section of suitcase the same for small or big block??? If your going completely back to a non A/C setup then yes the inside heater duct system and controls on a non a/C car are all the same except for the heater core itself. They carry different assembly numbers in the assembly manuals but I think that that is because they are an assembly that already has the heater core inside it and not a series of individual part numbers.
The inside duct system is completly different between an A/C system and a non A/C system so how much you need to replace depends on how thorough the previous owner was. The only part that is the same between the two systems (A/C and non A/C)is the defroster ducts' and the air louvers in the corners of the dash.
Apr 14th, 03, 01:39 PM
Are the inside portions the same for small and big blocks? (non AC)
Apr 15th, 03, 12:05 AM
Yes, see above.
Apr 15th, 03, 05:39 AM
Thanks Mark, that's great.
I see where someone fiberglassed over the holes in the cowl, so now i gotta try to find the inside portion of the heaterbox for a non AC car and whatever ducting I can get my hands on. I'll also pick up an aftermarket firewall side heat box for big block, a heater core and have at it... of course i'll need to weld in some steel to fill the hacks
Apr 15th, 03, 08:58 AM
I just found this forum and hope no one minds if I join in, but I'm trying to accomplish the same thing. I have a standard 350 car that I am trying to convert to a Z-28 clone and want to remove the A/C. I have all the parts except the ducting required for the side vents. I'm willing to forgo the outside vent air if it is very difficult to accomplish. I would like to know what changes, if any, have to be made to the large hole on the passenger side behind the kick panel. Is this hole suppose to be covered in the heater car?
Thanks for any assistance.
Apr 15th, 03, 01:45 PM
No, the large hole and the one like it on the drivers side act as floor vents in a non A/c car. The Non A/C kick panels have cable operated doors in them that you open and close from the sliders on the rear edge of the kick panel. A/C cars only have a single slider on each side that operate the upper air vents. Non-A/C cars have two sliders. One opeates the upper air vents (but in a different location) and the other operates the doors in the kick panel.
Before you jump into this do a search in this forum and in the electrical forum to see what your getting into. It isn't as simple as it first appears to be. and while it probably costs at least $1000 to put A/C into a Non A/C car, I would bet it will cost you at least $300 to convert to a normal heating system in an A/C car.
Apr 16th, 03, 06:19 AM
I really appreciate your help. I just received the new kick panels(non A/C) and see what you mean about the vents and sliders.
When I did the original restoration on the car, I purchased a new dash wiring harness, and it appears it has both A/C and non A/C wiring installed, so it looks like I just have to plug in the heater speed connector( I hope) and tie up the A/C wiring. I have already purchased the new heater inner and outer box, heater core, and dash heater control, so it appears I have most of what I will need. The one thing I don't have, and haven't been able to find, is the duct work for the side dash vents, but I think I saw your post where this is a problem to hook up anyway, so I just planned on not making them functional. I also do not plan on replacing the dash pad, so I will have a non-functioning center dash vent, but I'm not attempting to create a concours car so it won't matter.
I did have one other question. Are you suppost to seal the kick panel vents around the hole area? If so, is there any particular type sealer you recommend?
Thanks again for your help.
Apr 16th, 03, 07:48 AM
the a/c harness is an Add on harness that consists of the bundle of wires that run through the 1" diameter rubber grommet in the firewall. The only place it hooks into the original dash is at the power connection to the NON A/C fan control switch wire (the hot one). GM just cut off the connector to the fan control switch and spliced it into the A/C harness. Everything else in the a/C harness just plugs into the various connectors on the back of the heater control panel and the door switches on the top of the inner heater box. You can just yank the whole thing out, if your going to patch the firewall where the grommet goes. The power feed to the High speed fan is a separate wire with a fuse in it that is tucked into the wireway above the distributor and runs over to the relay from the horn relay.
The stuff that seals the back of the kick panels to the metal structure of the car is refered to as Dum-Dum. It's kind of a grey putty based caulk that looks like playdough. I don't know if you can get it anywhere. Closest stuff to it that I know of is window glazing putty (for those old enough to remember actually having to replace individual panes of glass in a house window, or electrical conduit duct seal (used to keep water from getting into the open end of vertical conduits in industrial plants).
I've got a set of the upper dash vent's in my attic but in order to install them you need to cut about a 2 1/2" to 3" hole in the cowl area under the leading edge of the windsheild. If you look at the firewall just under the dash through the glove compartment opening you can probably see three dimples in the firewall. These are the holes for the bolts that hold the upper dash vents to the firewall. there is another set on the driver side in the same location. The vents are a plastic piece of duct with a flange on it to attach to the firewall, and there is a damper built into them that is operated by the upper slide on the kick panel. The rear of these ducts are connected to the edge vents with short pieces of 3" black dryer vent hose.
The only way to access this area is through the glove box door, and to remove the instrument cluster. you would have to cut the holes from the inside out as you can't even see the holes from outside in the cowl area. Find someone with a normal heater system that has their cowl panel off. You should be able to reach up and back behind the wiper linkages and feel the duct pieces.
Apr 16th, 03, 08:17 AM
Originally posted by Mark C:
I don't know if you can get it anywhere. Closest stuff to it that I know of is window glazing putty 3M makes a strip caulk that has a similar consistency, but is black in color. 20 yards for $9.99 available thru Eastwood (http://www.eastwoodcompany.com) if you have that catalog. Possibly your local parts store might carry a similar product.
Apr 17th, 03, 09:17 AM
Thanks for the information. Do you want to sell the ductwork? If so, how much. Also, when the vacuum controlled flapper is removed from under the cowl, what happens to that hole?