AC Condenser Question

[Shep69 149]

My 69 came with factory AC. I’ve replaced all the under hood components as they were long gone when I purchased the car.

As my radiator it mounted behind the support and the condenser  is mounted in front of the rad support it creates a large gap . 

I’ve read that the condensor should be as close as possible to the radiator so it eliminates high pressure issues in the AC compressor and also stop turbulence between the two thus cooling the radiator more effectively. 

What have others done to overcome these issues?

[Vicfreg 771]

My condenser is mounted to the rear of the radiator support and is extremely close to the radiator.  Here are some drawings from my Vintage Air install that may help.

You can see my condenser in the picture mounted from behind.  It is so close to the radiator, that I had to modify the mounting bolts to keep the radiator from hitting (I have a larger radiator)

 

[Vicfreg 771]

The last 2 pictures are ones I had from some car shows, etc.  Show the same thing

[Shep69 149]

6 hours ago, Vicfreg said:

The last 2 pictures are ones I had from some car shows, etc.  Show the same thing

Thanks for the info bud. When I get home on the weekend I’m going to compare to see what the difference is on mine . I will let you know how I go . I’ve got a feeling my condenser is mounted in front and not like the pic . 

[Shep69 149]

On 1/27/2020 at 6:54 AM, Vicfreg said:

The last 2 pictures are ones I had from some car shows, etc.  Show the same thing

Just had a look at mine Vic and it appears to be the same as the pic but I’ve got a 2 1/2 inch gap between the radiator on condenser. I purchased it through classic auto air and it came with all the brackets attached and bolted straight in.

[Vicfreg 771]

I think that is probably ok then.  I will have to go back and look at my gap, but appears to be the same.

[aslanefe 333]

I have stock radiator and condenser and fan shroud at stock locations, using 180 F thermostate. Do not have issues with keeping the engine cool on daily driving.

[Shep69 149]

26 minutes ago, aslanefe said:

I have stock radiator and condenser and fan shroud at stock locations, using 180 F thermostate. Do not have issues with keeping the engine cool on daily driving.

Its not the engine temp aslanefe . Its the condenser  temp im worried about. High temps in the condenser means high pressure causing premature failure of the pump seals. I have just replaced a sanden style  compressor with a genuine unit due to front seal going so just want to make sure I've got things covered. My condenser is a about 2.5 inches away from the radiator so there a gap between them . Just wanted to know if this distance is normal.  Factory AC cars use the BB radiators so it sit further forward maybe.

[unilec 57]

3 hours ago, Shep69 said:

Its not the engine temp aslanefe . Its the condenser  temp im worried about. High temps in the condenser means high pressure causing premature failure of the pump seals. I have just replaced a sanden style  compressor with a genuine unit due to front seal going so just want to make sure I've got things covered. My condenser is a about 2.5 inches away from the radiator so there a gap between them . Just wanted to know if this distance is normal.  Factory AC cars use the BB radiators so it sit further forward maybe.

Do you get a ice build on the pipes near the evaporator? It could be the system is overcharged, may be a good idea to have a set of gauges attached to check the high pressure side.

[Shep69 149]

15 hours ago, unilec said:

Do you get a ice build on the pipes near the evaporator? It could be the system is overcharged, may be a good idea to have a set of gauges attached to check the high pressure side.

Hi Neil . 

No ice build up on the pipes. When I had the system gassed up the guy said that my pressure spiked due to the fact that I hadn’t set up my thermo fans to come on as soon as the AC is on. I fixed the straight away . I’m currently fitting two maradyne fans. These pull shit loads more air than the ones I currently run. You can tell when in traffic the ac isn’t as cold as when cruising down the hwy. 

[aslanefe 333]

On ‎1‎/‎30‎/‎2020 at 10:12 PM, Shep69 said:

Its not the engine temp aslanefe . Its the condenser  temp im worried about. High temps in the condenser means high pressure causing premature failure of the pump seals. I have just replaced a sanden style  compressor with a genuine unit due to front seal going so just want to make sure I've got things covered. My condenser is a about 2.5 inches away from the radiator so there a gap between them . Just wanted to know if this distance is normal.  Factory AC cars use the BB radiators so it sit further forward maybe.

I have used my factory condenser, evaporator and radiator. Changed the compressor to Sanden R-134 (and the hoses to fit Sanden), new filter/drier and R-134 in the system. I added a pressure switch just before the factory expansion valve which will cut the power to Sanden clutch when pressure gets high. You might want to add a pressure switch because as far as I know Sanden doesn't have pressure relief valve like the original York units have and if pressures get real high due to a malfunction/or not enough cooling, you will blow something.

[aslanefe 333]

By the way, my AC is not as cold in stop and go traffic as on highway either. This is due to using stock condenser and not having an electric fan come on with AC. Putting a stock fan shroud reduced the AC output temp in town driving (still not as cold as highway driving).

[Vicfreg 771]

The binary (or trinary) safety switch used in the modern replacement A/C systems protect the system from pressure limits, protect the compressor and prevent freezing up. It will also turn your cooling fans on/off as a first level of protection prior to shutting off your compressor.   On my vintage air system I have a trinary safety switch, it has the following settings:

 -

 - High pressure cutoff - >406psi 

 - High pressure cooling fans on high - >254 psi 

 - Low Pressure cutoff <30 psi (2.1 Bar)

 - 

[Vicfreg 771]

Try this again:

 - High pressure cutoff -                            >406psi  (28 Bar)

 - High pressure cooling fans on high -  >254 psi (17.5 Bar)

 - Low pressure cooling fans off             <175 psi  (12.1 Bar)

 - Low Pressure cutoff                               <30 psi   (2.1 Bar)

 

The difference between a Binary Safety Switch and a Trinary Safety Switch is that the Binary just has the compressor cutoffs, and the Trinary has those plus the cooling fan interfaces.

 

[Shep69 149]

4 hours ago, aslanefe said:

I have used my factory condenser, evaporator and radiator. Changed the compressor to Sanden R-134 (and the hoses to fit Sanden), new filter/drier and R-134 in the system. I added a pressure switch just before the factory expansion valve which will cut the power to Sanden clutch when pressure gets high. You might want to add a pressure switch because as far as I know Sanden doesn't have pressure relief valve like the original York units have and if pressures get real high due to a malfunction/or not enough cooling, you will blow something.

Yes my system has a pressure switch. You can see it in the pic that i posted. Its never cut in though. I have just replaced the two thermo fans with higher cfm units. I think this has made a huge difference. 

[Shep69 149]

2 hours ago, Vicfreg said:

Try this again:

 - High pressure cutoff -                            >406psi  (28 Bar)

 - High pressure cooling fans on high -  >254 psi (17.5 Bar)

 - Low pressure cooling fans off             <175 psi  (12.1 Bar)

 - Low Pressure cutoff                               <30 psi   (2.1 Bar)

 

The difference between a Binary Safety Switch and a Trinary Safety Switch is that the Binary just has the compressor cutoffs, and the Trinary has those plus the cooling fan interfaces.

 

Thanks Vic. My fans are hooked up to my FiTech unit . Unfortunately  my FiTech only has one fan controller and not duel fan setup like some. Ive also made it so when the AC gets turned on both fans come on as well. It seems to work well though. I put the new higher cfm fans in yesterday. They are the 12 inch Maradyne fans. Its hot over here , well over 100 deg and its made a huge difference. 

[Vicfreg 771]

I have FiTech, but I use a separate PWM Fan Controller, also with the 2-12" Maradyne fans.  I live in NASCAR country, and I got these from a shop that provides them to some of the NASCAR race teams.  They are about the best fans you can get, flow wise.

Much of my post on this was lost in the Photobucket fiasco, but these PWM controllers are used by the Military and commercial truck fleets.   Great design.  I use an in-line temperature sensor on the lower radiator hose to control the fans. I was able to move my engine temperature +/- 1 degree F during tests on my engine test stand in the summer.  North Carolina gets into the high 90's and stays there in the late summer months.  I was worried my 393 stroker would run hot.  But, so far, so good.

 

 

[Vicfreg 771]

IMG_3042.MOV

[Shep69 149]

16 minutes ago, Vicfreg said:

I have FiTech, but I use a separate PWM Fan Controller, also with the 2-12" Maradyne fans.  I live in NASCAR country, and I got these from a shop that provides them to some of the NASCAR race teams.  They are about the best fans you can get, flow wise.

Much of my post on this was lost in the Photobucket fiasco, but these PWM controllers are used by the Military and commercial truck fleets.   Great design.  I use an in-line temperature sensor on the lower radiator hose to control the fans. I was able to move my engine temperature +/- 1 degree F during tests on my engine test stand in the summer.  North Carolina gets into the high 90's and stays there in the late summer months.  I was worried my 393 stroker would run hot.  But, so far, so good.

 

 

Thanks for the info Vic. I will look into the fan controller.  Are you running that FiTech command centre. Ive heard nothing but bad things about them. FiTech have since updated this unit. I went in tank pump and love it. 

[Vicfreg 771]

I am running a FiTech fuel command center that has been modified.  I pulled out the float/valve assembly, and installed a full flow return line.   I did this after talking to the FiTech folks at the Hot Rod Power Tour last year.   The new fuel command center has this modification from the factory, and is much sleeker looking.   I had already purchased it, so I am going to give it a try.  Will get it started at Mikes (latoracing) in about 2 weeks, so will let you know.  I may want to get a copy of your tuning settings if you have driven with it for a while.

 

[Shep69 149]

2 hours ago, Vicfreg said:

I am running a FiTech fuel command center that has been modified.  I pulled out the float/valve assembly, and installed a full flow return line.   I did this after talking to the FiTech folks at the Hot Rod Power Tour last year.   The new fuel command center has this modification from the factory, and is much sleeker looking.   I had already purchased it, so I am going to give it a try.  Will get it started at Mikes (latoracing) in about 2 weeks, so will let you know.  I may want to get a copy of your tuning settings if you have driven with it for a while.

 

Just make sure you’re running the latest update Vic . 

I have it so if you need it just let me know and I can email it to you with the instructions. I have the update for the handheld without the white arrows. If your handheld has the white arrows around the joystick you need to contact FiTech. 

If you know how much vacuum your motor makes at idle this will help choose the cam and fuel table. 

 

[aslanefe 333]

On ‎2‎/‎3‎/‎2020 at 8:12 PM, Shep69 said:

Yes my system has a pressure switch. You can see it in the pic that i posted. Its never cut in though. I have just replaced the two thermo fans with higher cfm units. I think this has made a huge difference. 

If you have a pressure switch (that is working properly), you shouldn't worry about high pressure damaging pump seals (even if you do not have enough cooling over the condenser). My pressure switch has never cut either in the last year or so that I have been daily driving the car, I think that means my original clutch fan is doing a decent job in my climate. Looks like you have more than enough cooling and the pressure switch will be your insurance if the electric fans fail for some reason; I wouldn't worry about the gap between the condenser and radiator. Cheers

[bigmal 225]

Hi Shep,

I recently had problems with my compressor (Sandon 134) squealing. As I hadn't used it over winter I assumed it had failed so ordered a new one from CJPP. When it arrived I rang my aircond guy to arrange gassing after install. He asked a bunch of questions and then advised that the compressor is probably OK but the system is over pressurising.

What I had done: I had jus installed a twin thermo fan setup. The fan controller I used failed strait away so I just used the temp switch to turn on/off but did not have it set up to come on with the aircond. Before the fans were on the system was over pressurising and stalling the compressor. When I wired it to come on with the compressor the aircond was back to normal. I have since removed the thermo fans and gone back to my original flex fan setup as the fans were not as efficient and the temp gauge was reading higher than before although not boiling.

I have the same radiator condenser setup as you with a similar gap and had considered making a seal between the condenser and radiator but now I have gone back to the flex fan it is working fine. If I go down the thermo fan path again I will look at a seal. Possibly black foam or similar.

Now I have a new Sandon 134 compressor as a spare. An expensive spare!

[Shep69 149]

6 hours ago, bigmal said:

Hi Shep,

I recently had problems with my compressor (Sandon 134) squealing. As I hadn't used it over winter I assumed it had failed so ordered a new one from CJPP. When it arrived I rang my aircond guy to arrange gassing after install. He asked a bunch of questions and then advised that the compressor is probably OK but the system is over pressurising.

What I had done: I had jus installed a twin thermo fan setup. The fan controller I used failed strait away so I just used the temp switch to turn on/off but did not have it set up to come on with the aircond. Before the fans were on the system was over pressurising and stalling the compressor. When I wired it to come on with the compressor the aircond was back to normal. I have since removed the thermo fans and gone back to my original flex fan setup as the fans were not as efficient and the temp gauge was reading higher than before although not boiling.

I have the same radiator condenser setup as you with a similar gap and had considered making a seal between the condenser and radiator but now I have gone back to the flex fan it is working fine. If I go down the thermo fan path again I will look at a seal. Possibly black foam or similar.

Now I have a new Sandon 134 compressor as a spare. An expensive spare!

Hi Mal,

I have just fitted two 12 inch Maradyne fans just like Vic and man they suck some serious air . Those other fans I was running are rubbish. No more high motor temps and the condenser seems to be pretty good now. They fit perfect side by side on the shroud that I made up . 

I’m running a 190 deg thermostat and it sits just above that now even on the 43 deg C day we had in Perth the other day.  If you thinking about going electric fans again I highly recommend these .  I purchased them for about $180 each from a place in Adelaide. 

Its always good to have a spare compressor . 

[bigmal 225]

Thanks Shep, if I go down the thermo fan path again I will definitely try them.

Currently chasing a miss which is keeping me occupied. Ordered a new dizzy, coil and leads. Sick of fiddling so replacing everything.

I'm not clear, but do you still have an issue with the aircond?