I want to AC my 71 and need to know if the firewall is the same for the AC/nonAC cars or if it is just better to go with a complete aftermarket setup like vintage air
or others. thanks!

You might want to post in Heating/Cooling for better results. I think your question refers to whether or not the firewalls are the same for factory a/c and non a/c cars? If so, the answer is no. Some of the cutouts, like the one for the blower motor is the same but some of the others are not. To add "factory air" to a non air car, you would have to modify the firewall to accomodate the factory air components. That usually involves finding a factory air car and using the firewall as a template. You will also use the brackets, pulleys, evaporator, condenser and controls from the donor car; remembering that all of the components are going to be old and some might not work. There is the added problem of converting the old system to the modern R134A refrigerant, or charging the system with very expensive R12. Adding Vintage Air to a non factory air car is pretty straightforward. They make a kit that includes all of the components you will need. The installation instructions are not very thorough, but the system works pretty well when you are done and it uses the orignal heater controls to work it. To add V A to a factory air car, you would order their unit for a non factory air car and close off some of the factory air openings in the firewall. In either case, there will be a small opening for the heater hosed and a/c lines in the firewall for the Vintage Air unit and that opens up a lot of room for working on your engine. Here is a pic of my engine compartment (a 65 factory air car converted to VA): http://chevelles.com/showroom/JimN/engine2.JPG
You will notice the metal plate bolted to the firewall and a small plastic box where the hoses exit. The metal plate is the cover I fabricated to cover the holes in the firewall. The plastic box comes with the Vintage Air unit.
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65 Danube Blue MALIBU 4 door wagon, Disc brakes, F41 suspension,
GM Performance Parts 350/330hp crate engine with serpentine belt system, electric cooling fans, 700R4tranny, Sanderson headers, flowmaster exhaust, factory air with Vintage Air conversion, tilt wheel. http://chevelles.com/showroom/JimN/Maliburearview0006.jpg

[This message has been edited by JimN (edited 01-19-2003).]

[This message has been edited by JimN (edited 01-19-2003).]

[This message has been edited by JimN (edited 01-19-2003).]

Nice Pic JimN
My Laguna has factory air, but missing just about the whole system. from the Giant Evaporator forward. Plus the factory spagetti hose system is balky and slow.

I am planning on going to a Vintage Air system, how happy are you with the changeover?? I would love to loose the giant box on the firewall. Plus my buddy can smooth out my firewall afterward to make it look stock!!

My only concern is getting the system to work with the stock vent controls and ducts. to look stock from inside All that stuff works ok in my car, just the vac motors are slow and balky, just curious!!!

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Frank W
G-3 Chevelles Rule
74 Laguna Type S-3 Warmed over 305
4 bolt 454 now in garage 3.42 Posi
90 Mustang LX Notch 5.0/5 speed daily driver
Homepagehttp://www.chevellepages.com/folingo
Club Page clubs.hemmings.com/bearingburners (http://clubs.hemmings.com/bearingburners)

Frank, the vintage air setup is okay. I have not really tested it in the hot summer to see how it cools, I installed it in September. My setup uses the GM compressor, so I had to fabricate all the hoses. The heater is very strong, but there is no way to regulate heater temperature except by turning the blower on and off. The other disadvantage is that the system uses only recirulated air, no fresh air is drawn into the car. If your vehicle is a 73 with factory air, the heater, a/c and blend doors in the heater box are vacuum controlled. You will probably have to modify your heat/ac controls to use cables or Vintage makes a unit with electric controls that might be adaptable to your setup.

Looks good Jimn- My car is non ac and I was needing to know if the only option was an under dash deal or if they stuffed the condensor in the existing heater box somehow?
I was hopping to use a compressor from a 5.0 mustang as they are a very efficient rotary design I am told . Thanks.

67johnny,I added V A to my 66 non air car and it was a piece of cake.Instructions were exactly like the car was http://www.chevelles.com/forum/biggrin.gif Only complaint is the low speed isn't low enough. Also the V A side vents were cheap plastic that stuck out a mile,so I got a pair off my parts car(stock) and used them instead,looks factory now... But it cools and heats great http://www.chevelles.com/forum/cool.gif

Rick

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66 300 Deluxe 350/330hp
72 Elcam 402SS---soon to be a roller cammed 454

Also, the instrument panel for the AC car is different. It has the registers molded in. Not sure if the opening for the heat/Ac control panel is the same. The retrofit kit may be the easiest in the end.

Yes, the firewall is significantly different. On your '71, you need to know that the VA custom fit unit for '70 doesn't fit 71-72 (VA told me this on the phone) and that trying to make it fit is a bear. They were looking into doing a custom fit unit for 71-72 at one time, but don't know if they ever did.
Probably have to go with a universal fit unit.

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Phil
"I don't believe I'da told that"

Uncle
I was just out to the shop looking at my 70 parts car and I just cant see any physical differences between the 70 and 71 non AC SS dash cars!
Did VA say the 70/71 non AC cars were not kit interchangable? Thanks.

67johnny, Vintage Air doesn't make anything that fits in the existing heater box. Their kit replaces the heater box. If you are using the VA setup, they will supply you with the compressor and brackets with their kit. The compressor is a Sanden unit, which is very efficient and a great design. The Sanden is used in a lot of import cars. My BMW had one. If you decide to use the Ford compressor, check with VA to make sure it is compatible with their system; also, you will have to fab up your own hoses, fittings, and compressor brackets. a chore that adds hours and aggravation to the project (I know, I did it). If your budget permits it, or you have the time to scrounge the junkyards for an 80's Camaro, you can go the serpentine belt route and use a GM rotary compressor. Check out this post for more info: http://www.chevelles.com/forum/Forum31/HTML/000190.html

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65 Danube Blue MALIBU 4 door wagon, Disc brakes, F41 suspension,
GM Performance Parts 350/330hp crate engine with serpentine belt. Electric cooling fans, 700R4trans, Sanderson headers, Flowmaster exhaust, factory air with Vintage Air conversion, tilt wheel. http://chevelles.com/showroom/JimN/Maliburearview0006.jpg

[This message has been edited by JimN (edited 01-22-2003).]

[This message has been edited by JimN (edited 01-22-2003).]

JimN-That site with the serpentine setup you linked us to was brilliant! It in the favorites now. Thanks.
ps. that ford compressor is sanden rotary as well I believe.

Johnny

Do some research man. Use the search options for posts in Heating and Cooling as well as posts with my name in the 2003 Tech Forum.

I laid it all out about the firewall just a few days ago. THE FIREWALLS ARE DIFFERENT BUT IT AINT A BIG DEAL!

The firewalls are different between non A/C and A/C cars. They are however the same between all non factory A/C cars from 68 to 72. The firewalls are also all the same for all factory A/C cars from 68 to 72.

Just do some research it is all here all spelled out.

[This message has been edited by oman (edited 01-26-2003).]

<BLOCKQUOTE>quote:</font><HR>Originally posted by 67johnny:
Uncle
I was just out to the shop looking at my 70 parts car and I just cant see any physical differences between the 70 and 71 non AC SS dash cars!
Did VA say the 70/71 non AC cars were not kit interchangable? Thanks.<HR></BLOCKQUOTE>

That is cause there AINT no physical difference. VA's Tech line and Sales line is full of ****. They say they don't make a kit for 71 / 72 because 71 and 72 factory A/C equipped cars use two cables and the VA kit requires three cables. The dash control panels on 71 and 72 factory A/C equipped cars have two cables NOT three like I said but the dopes in tech support at VA don't know enough to tell ya what I am tellin ya here. They don't know enough to tell you WHAT I HAVE ALREADY POSTED HERE FOR ALL TO READ.

If you buy a VA kit for a 68 to 70 Chevelle that came with factory A/C and you use a dash control unit with 3 cables from any Chevelle or Monte that came without A/C you can use the kit Va sells for 68 to 70 Chevelles in a 71 or 72.

The fit issues are the glove box and the defroster duct. THESE ARE ISSUES WITH ANY OF THE CARS FROM 68 RIGHT UP THRU 72. The VA kit ain't the best in terms of these two areas BUT the issues are not a result of using a 68 to 71 kit in a 71 or 72 car. The issue is the FITS ALL nature of the VA Sure Fit kit not the fact that you are crossing over to a 71 or a 72 car with a 68 to 70 kit. The cars are fundamentally the same. There are SLIGHT factory wiring harness difference between the years but that does NOT MATTER if you go with VA. If you load in an all GM OEM system as long as all the wiring is from one year everything physically fits and works.

All this data is DOCUMENTED ALREADY in HEATING AND COOLING and or the 2003 Tech Forum.. Do the search man!!!!!!!! Do the search!!!!!! If all the capitol letters here show my frustration GOOD. I have done both the conversions: Non factory A/C to Factory A/C AND Factory A/C to Vintage A/C. In both cases it was done on 72 cars. I shared my information for everyone to see but what happens.....MORE and MORE AND MORE questions about the firewalls and VA not makin kits for 71 /72 cars. I bet I have written AT LEAST 2500 words about this already and STILL people re-ask the same questions.

SEARCH SEARCH SEARCH and ye shall find.




[This message has been edited by oman (edited 01-26-2003).]

Johnny

Do some research man. Use the search options for posts in Heating and Cooling as well as posts with my name. I laid it all out about the firewall just a few days ago. THE FIREWALL ARE DIFFERENT BUT IT AINT A BIG DEAL!

Just do some research it is all here all spelled out.

[This message has been edited by oman (edited 01-27-2003).]

Oman-Much appreciated! I really should use the search feature more and I guess my take on it has been that a fresh question may illuminate the latest and greatest new products that are now available although its never a good thing to overlook the tryed and true!.
Off to "search land" Thanks again.

<BLOCKQUOTE>quote:</font><HR>Originally posted by 67johnny:
Oman-Much appreciated! I really should use the search feature more and I guess my take on it has been that a fresh question may illuminate the latest and greatest new products that are now available although its never a good thing to overlook the tryed and true!.
Off to "search land" Thanks again.<HR></BLOCKQUOTE>


Sorry if I got heavy handed....I just had to vent. This is not a trivial job whichever one you choose to do. It seems that a lot of people want to do one conversion or the other and the info I learned and shared was hard to come by.

Nobody seems to want to look for info. A couple of Keywords like Vintage Air, Firewall and I dunno a few others would also work then the system leads em right to the info. Perhaps they need their mothers to look this stuff up for em?

The other thing to watch out as you take this on. Unless someone has spent a lot of time doing this they don't understand and assumptions get made that can lead to a lot of work or to one of those "Ah S--it" monemts when you are 3/4 thru the conversion and figure out that you have incompatible parts and pieces.

Depending which way you decide to go I can give ya additional info about the specifics of the VA redo that is not already here. I have an onging research project in the works as I finish up the VA conversion and I am more than willing to share. The VA kit is not a bolt in and depending on how fussy you are (I am VERY fussy) you will have to do a fair amount of work with what VA supplies you.

Specifically the defroster duct system they supply is a joke and ya gotta eather use the VA replacement glove box or shorten your glove box about 2 inches. Va sent me the wrong replacement glove box in my kit and did not want to hear about anything when I called them. They fell back on the "Well the kit is for a 68 to 70 and you are working on a 72" crap cause they don't know what they are talkin about. All they wanted to do was move on to the next call.

After you read the firewall explanation for the OEM system install you will see that it is more or less mindless to swap in factory A/C particularly if you already have a donor car. The down side of the factory A/C is that ugly evaporator box on the firewall and the fact that it is an R-12 system.

I have not gotten involved in conversions between R-12 and R134 for the OEM A/C units but I am beginning to believe more and more that it can be done with a different expansion valve and a different condensor. That condensor is however gonna have to be VERY efficient or VERY big. R134 systems require about +20% more surface area and / or more condensor efficiency and there is not a lot of room up there in front of the radiator for more surface area.

Even if ya do convert the OEM system to R134A ya still have that huge evap box on the engine side of the firewall. I just accepted that as "the way it is" but now after gettin rid of the damn thing I really like the spiffy look of the firewall.

oman-Sound like the aftermarket firewall setup is the way to go! Thanks.

<BLOCKQUOTE>quote:</font><HR>Originally posted by 67johnny:
oman-Sound like the aftermarket firewall setup is the way to go! Thanks.<HR></BLOCKQUOTE>

The aftermarket firewall???? Do you mean the aftermarket system with the clean firewall or do you mean the donor car firewall as modified per my instructions and installation of the donor car OEM A/C system????

Hey Oman, did you ever get an answer to that vintage air condenser size question we were kicking around here a few weeks ago?

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65 Danube Blue MALIBU 4 door wagon, Disc brakes, F41 suspension,
GM Performance Parts 350/330hp crate engine with serpentine belt. Electric cooling fans, 700R4trans, Sanderson headers, Flowmaster exhaust, factory air with Vintage Air conversion, tilt wheel. http://chevelles.com/showroom/JimN/Maliburearview0006.jpg
Engine pic: http://chevelles.com/showroom/JimN/engine2.JPG

[This message has been edited by JimN (edited 01-27-2003).]

<BLOCKQUOTE>quote:</font><HR>Originally posted by JimN:
Hey Oman, did you ever get an answer to that vintage air condenser size question we were kicking around here a few weeks ago?

<HR></BLOCKQUOTE>


All data says "bigger is better" up to a point. Where that point is seems to be unknown. Bigger just seems to help cover up sins like insufficient air flow over the condensor. Same way as the the way a biggger radiator can help overcome less than optimal air fow thru the grill area.

Here is what I know so far....been meaning to gen up an answer to all you guys but been busy with other stuff!

1. VA says 20x12 is adequate but I conclude that everything like airflow and the amount of charge in the sys. has to be right on target for the 20x12 to get the job done. Not a lot of room for error.

2. Airflow thru the evap is also important. VA's Chissenhall, in a book he co-authored with somebody or other, says that "If you want to go the extra distance use smooth walled tubing to plumb your inside car vents." Apparently the flex tube inner walls are conducive to turbulence in the ducts and turbulence causes the fan to cavitate. Result....less air flow over the evap. Result ...not so cool a feeling in the car.

I am currently finishing up plumbing my in dash ducts with smooth walled hose. I used a combo of PVC pipe on some ducts and radiator hose on the others. PIA to get the right hoses from the parts store by looking at pictures and saying "Send me one of those" but I am almost done. If you gotta work with the usual parts store "year make and model" guys on getting radiator hoses for use as air conditioning ducts your gonna have trouble. Also you should use plastic or rubber hose if you do swap out the flex stuff. Metal pipe will form condensation and water inside the ducts equals bacteria and smelly A/C.

3. I will be going with a 24x14 unit for my evaporator. A guy on the Vette forum has a mid year Vette with a VA Sure Fit (same indash unit we use) and he has a 24 x12 if memory serves me right.

That is what VA shipped with his kit. That sizing seems to reinforce BOTH the bigger is better and insufficient flow is bad theories at the same time. I say this cause mid year Vettes have VERY little flow thru the grill. VA recognized that and sent a bigger unit. Given the poor air flow the larger condensor keeps the refridge in the condensor longer giving it more time to return from a gaseous state to a liquid state.

4. Direct drive or electric fans seem to be the answer. I talked to a guy down here in Atl. who has a lot of Street Rodding experience with this stuff. He swears by electric or direct drive and swears at cluthch fans. The fans (whatever you use) should deliver 2300 CFM or more for adequate in town condensation of the refridge. (According to Chissenhall's book)

Hope this helps


[This message has been edited by oman (edited 01-28-2003).]

Oman-Going aftermarket system with clean firewall look! Thanks.

<BLOCKQUOTE>quote:</font><HR>Originally posted by 67johnny:
Oman-Going aftermarket system with clean firewall look! Thanks.<HR></BLOCKQUOTE>

Check your E-mail. Data on down and dirty of VA install to follow. Please advise on what you read and think.