AIR CONDITIONING
FOR SLANT SIX VALIANTS.

Hello fellow Valiant owners. My name is Brett Goodridge, and I have been a member of the Club since 1992. Unfortunately, my part-time university studies over the last couple of years limited the amount of time I could spend with the club .... 1998 will change all that. At the time I joined the club I was a proud owner of a green “S” (which I sold about eighteen months ago). I currently own a gun metal grey VC Regal sedan (which was at the recent All Chrysler Day), and I am now playing around with a VC Regal Safari wagon. One day I will play again with another “S”.

I have owned the VC sedan for about 12 years, and the car has looked the way it does now since 1992, following a complete bare metal respray, new interior, motor, drivetrain etc. The VC has been my daily driver for the last two years, and along the way I have added many “creature comforts” to make driving the car more enjoyable. These mod cons include: extensive sound proofing everywhere (this makes a huge difference); mobile car phone; CD stacker; cruise control; VG Regal seats; limited slip diff; ventilated disc brakes; front and rear sways; etc etc. The most important of all these add ons has been the air conditioning - I will never own another car without one (yes I am also going to put air con in the wagon as well).

Air con is pretty rare for a Slant 6 Val - installing a system is fiddly, but it can be done. Factory air conditioning for a slant six Valiant was fitted as an option only on the VF model - yes it was an option, although one “reputable” Chrysler aftermarket parts supplier will try and convince you otherwise. Of course air conditioning continued with subsequent Valiant models, but the 6 cylinder versions of these were all Hemi, rather than Slant six, powered. An easy way to install air con would be to try and find one of these slant six air conditioned VF’s, and transfer all the bits and pieces to your car (with some minor modifications). This is a good idea in theory, but good luck in finding such a car in a wreckable condition. The advantage of finding a VF is that the look of the system will roughly match the vintage of your car. This means that bits such as the evaporator will suit the interior of your Val, something a brand new aftermarket underdash black plastic unit fails to do. Also, finding the elusive VF system makes life easier when tracking down and fitting the right brackets and pulleys.

My system had originally lived in a VE Val - it was an aftermarket set up similar to the Mark IV systems. This was good as I was able to use the evaporator (a 60’s unit that suited the look of the car), the compressor, the bracket for the compressor, the compressor pulley, and the pulley that sits on the harmonic balancer. If you are not mechanically minded, there are people out there who could make the bracket and pulleys for you. Outlined below is a summary of what I did with my car to get the air conditioning happening.

The Radiator
The most important thing to sort out first is the radiator. Running aircon makes your Val run hotter. My Val runs unleaded which also makes the car run hotter. Of course if your engine is modified to create additional horsepower (as my car is), more horsepower also results in additional heat. A number of modifications were made to my radiator to compensate for all this additional heat.

The radiator in all early model slant six powered Valiants restricts the options available to get rid of the additional heat. Firstly, the width of the radiator support panel is a problem, and presents some difficulties when installing a larger (and therefore wider) radiator in the car. I did not do this to my car, but one option is to have some panel beating done to widen the radiator support panel to fit a larger (wider) radiator. The larger radiator would have to be modified by the radiator shop to ensure radiator hoses and transmission lines (for the Torqueflites) all still fit.

The second problem with the radiator is the limited gap between the radiator and the front of the engine block. This gap limits the size of the fan to be used, and the installation of a clutch fan is an impossibility. My radiator is a special wide two core (ie. it has larger diameter coolant tubes), rather than three core unit. Running a three core unit means the gap between the radiator and the fan is a bit unrespectable. The three core also restricts the airflow - you have to have a pretty good fan to drag air efficiently through both the newer style condensor and a three core radiator (particularly at idle or crawling speeds). You should have about 3/4’s of an inch gap between the fan and the radiator and good engine mounts to ensure that your fan doesn’t chew out your radiator under hard braking. To give some extra space, my radiator core was moved forward to give more room.

The final problem with the Valiant radiator is the positioning of the inlet and outlet hoses hoses - one is directly below the other. This is not good for radiator efficiency, as a significant percentage of the hot water entering the radiator at the top hose falls directly to the bottom hose and re-enters the engine without travelling through much of the radiator ! I did not do this to my car, but the radiator can be modified to have the inlet hose moved to the other side of the top of the radiator, forcing all of the hot water to work its way through the radiator.

A coolant recovery system also helps the radiator perform its job - it both by eliminates air pockets, and captures water that would otherwise be lost through the radiator overflow when the engine is running at operating temperature for an extended period. When the engine is switched off and the water starts to cool, the subsequent partial vacuum created by the coolant recovery system pulls the previously overflowed water back into the radiator. My car has a coolant recovery system installed.

Fans and the Shroud
The fan is basically there to suck air when the car is stationary or cruising at speeds of less than 50 to 60 kilometres an hour. The fan I used is off a VJ Val which had air con. It has 7 blades, and is designed so that the ends of the fan blades tapers to a point where, when it spins, it just misses hitting the front of the air con compressor.

It is also a good idea to have a smaller water pump pulley fitted (but not too small). The smaller pulley serves two purposes, the fan blades spin faster (therefore sucking more air through the radiator), and secondly, the water pump is moving the water quicker through the whole system. However, a word of warning, a too small a pulley will result in water pump cavitation. I am no engineer, but cavitation basically means that the water pump punches a hole in the water flow without actually moving the water through the system to any great affect. Cavitation fills the important bits of the motor (such as the cylinder head) with a whole lot of little bubbles, which act as an insulator (or blanket) inhibiting the cooling system in effectively doing its job in cooling the engine. A too small water pump may also result in the water pump pushing the water too quickly through the radiator, meaning that the water is not sufficiently cooled by the radiator before it re-enters the engine. Another warning about a too small water pump pulley is the potential at high revs for your fan blades to detach themselves as a result of the high speed the fan spins at - a potentially messy problem.

My car has a custom made shroud which is a big help, as it ensures that air is sucked through the radiator and from nowhere else. What is important with the shroud is to make sure that about half the fan sits within the back of the shroud. I have also managed to squeeze in 2 small thermo fans in front of the condensor (one is 9 inches in diameter and the other is 8 inches in diameter). From memory, the fitment of thermo fans may be a bit tricky in an “R” or an “S” due to limited space (particularly with the “R” and its bonnet latch mechanism). The thermo fans are wired to kick in when either the air con is on, or via a thermatic switch, which cuts in when the temperature of the cars hits 90 to 95 degrees Celsius.

Compressor
My compressor is one of the early rotary compressor types. Many 60s cars actually used an even early reciprocating piston type of compressor. To run with the new R134a gas, I had to get the compressor lubricant changed, as the R12 lubricant doesn’t mix with the R134a. My compressor sits roughly above the water pump, which meant I had to modify the bend in the first pipe of my extractors to make sure it was a neat fit. There would have been no such problems with the standard exhaust manifold.

Condensor
I binned the condensor that I originally got from the VE Val’s system. With the new R134a gas, heat has to be removed more efficiently than the older R12 type system. The older style condensors are designed where one winding tube runs back and forward between the fins - not very efficient. My condensor is the newer type which has a series of horizontal tubes running into manifolded ends - the theory is that the heat is removed more quickly and effectively (which is assisted even more with the installation of thermo fans in front of the condensor). In the VC I had to modify the front bonnet latch support bracket to fit the condensor and thermo fans. You should leave as much gap as possible between the condensor and radiator core.

Receiver/Drier
Receiver/Driers from an R12 system are incompatible with the new R134a system, so mine is a new one. If the receiver dryer is mounted in the air flow, this also helps get heat out of the system. I did not have the room to do this, so mine is mounted vertically tucked away between the battery and radiator support panel.

Evaporator
You need to carefully think about the size and where you mount the evaporator in the car. The obvious spot is directly under the dash (underneath the radio). The problem with this is that it restricts easy access to fuses and other essential bits and pieces. The other difficulty is that if the evaporator is too wide, your knees will hit the edge of the evaporator. I have seen the evaporator mounted under the glovebox in some cars, which would be fine on a hot day if you were the passenger in the car. I mounted the evaporator in my car about half way down between the bottom of the dash and the top of the transmission tunnel. I have had a custom made centre console fitted around the evaporator to make the whole thing look integrated. Another way around this, would be to move the fuse box to under the glovebox - given that I am colour blind, I did not explore this option any further !

Fuel system
Some of you running the standard single barrel carburettor may find the air conditioning can cause some problems with the fuel system. My car runs a modified 350 Holley so I did not strike any of the following problems. Firstly, the standard fuel line may need to be re-routed to avoid missing the compressor. Secondly, the extra heat that the air conditioning system creates in the system may cause fuel vapourisation or difficulties in hot starting of the car. One way of fixing this may be to install a fuel vapour return circuit as fitted onto some CM models.

Transmission Oil Cooler
For those of you with automatics, if you can find some room, a good idea is to install an aftermarket type transmission cooler. This helps in getting heat out of the engine, and can be installed to work in conjunction with the factory transmission cooler in the bottom of the radiator, or to completely replace the standard factory system .

Air Dam Spoiler/Scoop
On my VC, almost one third of the radiator was obscured by the bumper and other parts of the front end assembly of the car. I fitted a small (almost undetectable) air dam spoiler/scoop underneath the car behind the bumper bar, which serves a number of purposes. Firstly, it pushes more air into the radiator (particularly at speeds above about 40 km/h), which assists with the cooling process. Secondly, depending how the air dam/spoiler is designed, at idle it stops hot air exiting the bottom of the radiator (after passing through the fan), and recirculating itself again to the front of the radiator.

Window Tinting
Tint your windows - it helps the air conditioner do its job. I initially did not have tinted windows when I installed the air con, but I now have - it does make a difference. A rear window venetian also helps.

Heater
I am sure we have all been in traffic jams on a boiling hot day watching the temperature needle rise to an unrespectable level, and then switch on the heater to get rid of some of the heat. Another way the heater can assist with the engine cooling process is to restrict the water flow through the heater. The theory here is that such a restriction will mean more coolant is circulated through the radiator. I did not do this to my car, but apparently fitting a smaller diameter heater hose fitting into the top of the engine block (ie. the heater inlet hose), will provide such a restriction.

These are just some of the ideas to consider when fitting air conditioning to your Valiant. It is largely a matter of applying a bit of patience and thought into the process. All of what I did to my car was trial and error to determine what worked the best. The air con now works fine, however, the system is obviously is not as good as modern day units. For example, as my car is an auto, at traffic lights I put the car in neutral when the air con is on (it helps the car keep cool). If you are stationary and caught in traffic on a hot day for an extended period of time, it is a good idea to also slightly rev the engine to help keep everything cool.

If you manage to fit the evaporator, condensor, fan, radiator shroud, compressor bracket and pulley yourself, this greatly reduces the cost when you send your car down to the local air conditioning shop for the final bits and pieces. It end up costing me less than $500 six months ago to have my local air con shop to change the oil in the compressor, mount the compressor on the bracket, supply and fit the receiver dryer, supply and fit all the new hoses (including drilling the two holes in the firewall and drainage hole in the floor), and to gas and test the system. But remember to shop around and find someone with experience with air conditioning systems on older style cars.

I hope this inspires a few of you to consider air conditioning for your Vals. Special thanks with this article (and for assistance with fitting air con to my car) goes to DG Automotive - 018 114 805 (Darren is a Valiant man), and to Bankstown Auto Radiator Repairs - 9790 5697 (ask to speak to Guy - a fellow Valiant enthusiast).