Ke20 Aircon (Retrofit or otherwise!)

[Bananaman]

Gday lads,

Rex's thread on retro-fitting aircon made me decide to finally see if anyone is in the know about this, thought it best to make a new thread. As some of you may know, i will be fitting a ca18det to my ke20 corolla in the not so distant future. I will be keeping this car for a good few years yet (and would like for it to be gf friendly), so the idea occurred to me to fit aircon as a part of the conversion. The ca18 will obviously have a compressor.

Now, just got a few questions.

-Ke20 did have aircon as a factory option (albeit a rare one) didn't it? But i assume it didn't work so well?

-What exactly does the gear under the dash do (never taken out a complete system before) - and would i seek to use the ke20 item (if it exists), or use the setup from a silvia? Depending on the answer to what it does (and how much of an effect on the quality of the system it has) would also be a factor on which one to use. Does anyone have a pic of the under dash gear?

-What are the implications as far as getting the whole system approved? Once i set it all up, do i need to get it complied / plated much as you would an LPG system?

I'm sure there is more to ask, but thats all that comes to mind for now. Any advice / help would be greatly appreciated.

Thanks
Bardin

[smitty1]

Good luck with the A/C. I didn't think that there was a real problem with the performance of the A/C in a KE20, I just thought it would have been a terribly expensive option back in 71 - 74. Wouldn't have done much good to the performance of the old 3k either.

When you work out the interoir bits of it, I would be very interested as well. I was thinking that I would use the heater box out of a KE30 - KE70 that had A/C and make it fit.

Cheers, Ian

[Bananaman]

Yeah, the interior side of things is the challenge - the engine bay piping etc is probably the easy bit. I do have remnants of an aircon setup from an s2 rx7 as it happens, everything from the firewall forwards - this may prove useful, given i won't be getting a half cut for the ca18. The condenser is rather large though, don't really want to ruin the flow to the radiator/fmic too much..

I think a large part of the problem with ke20 aircon would be finding it - if someone does have an aircon setup that they'd sell me from their ke20 that would be fantastic, or if someone knew where i could get one

I currently have 0 understanding of how the inside part works. You mean to say its purely a different heaterbox unit, with suitable piping and controls? A ke70 item would be ideal, and cheap too surely..

Don't get me wrong, i don't want to be making icicles inside the car, so long as it works reasonably well thats fine.


ed:

http://www.edmunds.com/ownership/tec...9/article.html

This site gives a decent basic summary. The aircon unit in a ke70 would be seperate to the heater unit would it not?

[smitty1]

From what I understand about car A/C, there would be 2 coils in the heater box. One would be your normal heater coil, with hot water running through the coil controlled by valves at whatever thedriver sets it at. The second coil would be for the A/C, with refrigerant doing the same. I think that if the heater box could be physically made to fit, the flexible piping could run off to the outlets, and the hot water and refrigerant lines as well as the wiring could be hooked up with a bit of work. I would think that it may be possible to hook up the original heater controlls to the box and just add an on /off switch for the A/C.

Cheers, Ian

[4DaDrift]

Edited post.

[myne]

Usually there's a plastic box between the fan module and the heater module. If you look under your dash you'll probably have a piece of plastic pipe about 25cm long there instead.
The actual hardest part of it imo will be finding that part - or another that lines up with the firewall cutout.
The actual system of aircon is fairly simple.
All you really need is 1 button to turn on the pump and that's it. All the rest is physical. Though there might be a second pressure switch as part of the condenser that basically wont allow it to turn on if the pressure isnt high enough.
Once you have the radiators, the pump and the condenser all you really need is some piping and that small bit of electrics.

[Bananaman]

I'm sure a shop probably could do it with relative ease - but i'd rather do the best part of it myself, to save on labour costs - i don't intend on it being an excessively expensive luxury I will need to speak to a shop regarding complying it, but its early days at this stage - i just want to start getting my head around what will be required, what parts i should keep an eye out for, etc. Unless someone knows of a shop that doesn't mind a yarn, your average shop probably won't want much to do with me.

[Bananaman]

Usually there's a plastic box between the fan module and the heater module. If you look under your dash you'll probably have a piece of plastic pipe about 25cm long there instead.
The actual hardest part of it imo will be finding that part - or another that lines up with the firewall cutout.

As far as getting it through the firewall goes, given i don't think i even have the remnants of a system, i'll have to put the holes through and fittings on (i'm sure a suitable donor car could be found). I'll have a look at my bay and see if theres an obvious place it would have gone through later.

I'm not sure what you mean about this piece of pipe, or what you mean needs to line up with the firewall cutout, i'll have a geeze under my dash when i get home.

So, to clarify - as far as turning the system on, all that is required is a switch to actuate the clutch on the compressor? And hey presto its turned on, just need to turn on the fan? On modern cars you can't turn the aircon on without the fan (duh) - would i need to wire it in the same fashion to ensure something doesn't freeze up or similar?

[myne]

Well, we are talking a fairly simple system. Turning on the interior fan would be done via the normal means(a lever you move?). The std heater fan blows THROUGH the AC radiator and then through the heater (or not - if the red/blue hot/cool slider thing is set to 'cool')
By lining up with the firewall I mean there is a plate covering a hole in the firewall that the 2 AC pipes go through. Obviously it's neater to use the provided holes. and better still if you can get the stock one that mates perfectly to the fan module etc.
Engine bay AC radiator fans can be done via a relay running from the single switch in the dash.
AC isnt really that complex.

Effectively it's just this :
compressor which compresses the gas, making it hot
a radiator which cools the hot gas to ambient temperatures
condensor that expands the compressed gas, which makes it go really cold
a radiator inside the cabin with a fan behind it
And back to the compressor

Simple, yet so very nice

[takai]

Yeah, as myne was saying the hard bit will be finding the AC box to bolt to the inside of the car. However, a while ago i was thinking about how this could be done and came up with the following:

Since you already have the piece of pipe, rather than the airbox this will give you a pre-existing connection to either end, and S13 (or any other interior condensor of the right size) parts arnt that hard to find. You could simply gut the airbox inside the S13 or other car to get the condensor out, and then form up a simple box out of alloy (0.8mm would do) to contain the condensor. Now, since you already ahve that flexi pipe (the AE86 one is flexi) you have the end pieces to join to the blower and heater box. So simply cut holes in the end of the alloy box, to suit, and attach flexi joins so that air can be blown through the box. Finally form up suitable mounting tabs on the box to go to the firewall mounts and voila, one aircon box, and the rest is easy.

I would anticipate you needing the following to make that box:
0.8mm Alloy
Aircon bypass tube (to butcher)
Appropriate condensor (S13 or something the right size)
A few grommets to seal off the box; and
Foam to pad the outside of the condensor inside the box and force all the air through it.

I may do up a exploded diagram sometime.

[Bananaman]

stuff

Yeah, i understand how it all works now, through a read of that site and this thread, it all makes sense - i will just need to have a look at the piping in my own car. A relay to sort switching it on with the fan would be nice and simple. The whole system is in fact sounding alot simpler than i was expecting, i didn't realise the unit inside was just another condenser unit until now..

more stuff

Thats a pretty good idea, and i would agree that its the way to go - i can't weld myself though, so i'd probably form it up and give it to a mate to weld. Or i guess for something as low pressure (ie none) as an aircon box, using some sort of product like JB weld (or whatever its called, never used it) would do the trick? Or i guess i could bolt it together and seal it i suppose, is another alternative.

I'm probably not visualising it in the same way as yourself - the only way i can think of that the air would be forced through the box would be to have the fan inlet/outlet on opposite ends, but i gather this is not what you mean?

Only problem i can see with this idea though - the outside of the box would form a considerable amount of condensation wouldn't it?



I have all piping from the firewall forwards, but no fittings for the firewall (i assume you have a fitting on the firewall which you screw fittings to on either side?) - where does one get piping suitable for this (aside from wreckers, of course)? With some luck the only piping i'd need to buy for the compressed side of things would be between the interior box unit and the firewall.

+rep for you both, cheers for the help!

[74ROLLA]

G'Day Bananaman,

I actually bought a KE20 with A/C dealer fitted from new. Smitty1 now owns that car minus the A/C bits that were in it, as they are now sitting in my KE20 sorry Ian!lol

The only thing I need to get now as it was missing was the original evaporator. From what I have seen and studied (correct me if I am wrong if anybody knows!) I am going to use a seperate underdash unit from a KE30 which looks to be the same unit as a KE20?? (or very similar)

It is a very bulky unit but will just fit in with the KE25 lower dash panel I have fitted. I am going to fit the seperate unit as the original heater control only covers windscreen demist and floor. No vents to passenger except for external air!

Most of the original dealer fitted A/C is fitted to my KE20. I have seen how the original system was fitted. There is no fittings on the firewall, just the 2 a/c hose running through the firewall at the places ready for them (passenger side about 1/2 way down).

I can e-mail pics of what I do have so far if it helps . . . .

[Bananaman]

Hey mate,

Cheers for that, i thought that someone with factory aircon would be impossible to find! I'm gathering that its a massive unit that vents from the unit on the passenger floor, as opposed to going through the vents?

I've got the holes (well, templates) for the holes on the passenger side. It would be fantastic to see what it looks like though, if you would be able to email the pics to bardin-at-optusnet.com.au , that would be fantastic. Replace -at- with @ of course.

Cheers.

[74ROLLA]

I bought this KE20 from Canberra for the A/C! Smitty1 is now the proud owner of this and he has the cutouts in the firewall of his car. Also PMP020 on this forum has a KE20 with A/C, but not sure how his is done (he is in SA).

When I bought the KE20 with "most" of the air con, as I said the ONLY thing that was missing 'unfortunately' was the evaporator. Yes, it is a unit which has its own blower and vents, seperate completely from the heater controls.

It is rather bulky, and even most of the aftermarket type evaporators are fairly bulky! Still, a 197# car with A/C you have to expect that. I have not completely finished fitting the entire unit ( I wish I had in this heat, but work has been busy over Christmas!)

Also interestingly, the factory condensor etc (sits infront of the radiator) does not have a fan! It is a work in progress fitting it into my car and I cannot wait. . . . . . .

I'll e-mail you what I have, and maybe we'll catch up someday on a toymods cruise (bring your KE20, I like it!)

[rob20v]

Been looking at old posts and if anyone is still interested the KE55 AC/ heater unit looks fairly simular to the ke20 haeter unit and are readily available. I have a ke55 A/C system in my shed so I may have to dig it out and compare it with a KE20 one. I kept it for just such a mod in my KE25.