Advice on adding electric fans to existing radiator
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Registered User
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From: Dallas, Tx
Advice on adding electric fans to existing radiator
I have a O' Reillys 3 row copper/brass radiator on a 350 and wanting to get rid of the fan clutch and add electric fans. Does anyone know if another model fan would fit on the cutlass
'87 Delta 88 Royale
Joined: Dec 2010
Posts: 2,514
From: Margate, England
I recommend keeping the original fan complete with shroud, it was designed to work that way from the factory, and if everything is working properly you won't have any cooling issues.
A clutch fan won't be a parasitic drag on power, an electric fan might impede airflow at highway speeds.
Just my $02, it's your car and your decision.
Roger.
A clutch fan won't be a parasitic drag on power, an electric fan might impede airflow at highway speeds.
Just my $02, it's your car and your decision.
Roger.
Thread Starter
Registered User
Joined: Jan 2012
Posts: 585
From: Dallas, Tx
Besides the alternator upgrade are you overall happy with the set up. I already plan on doing a upgrade alt. I currently have a one wire 60amp. (I think)
Connoisseur d'Junque
Joined: Sep 2010
Posts: 21,183
From: The Hudson Valley
You may just have a bad fan clutch or a cruddy radiator.
Certainly we here can't hope to change what you know already.
When well maintained, these cars, which were on the roads by the millions back in the sixties and seventies, did not overheat and their A/C blew ice cold. If something is not working right, it is probably because one or more parts need attention, and not because the entire thing needs to be replaced.
Some people just like to change things because they can, and you certainly have the right to do that, but I think it's important to understand why you are making changes and the effects they will have before you actually do it.
- Eric
Beer Connoisseur
Joined: Aug 2008
Posts: 2,092
From: Daly City, California
This is my setup that's going in with my new engine. It comes together with Northern aluminum radiator and twin Spal fans. The fans pull 1630 cfm each. You can contact Universal parts and see if they will sell just the shroud and fans.
[IMG]
CR5026_RS1002HP by 70cutty, on Flickr[/IMG]
[IMG]
CR5026_RS1002HP by 70cutty, on Flickr[/IMG]
Registered User
Joined: Feb 2013
Posts: 15,310
From: Phoenix, AZ
What sort of problems? Car overheating? A/C not working?
You may just have a bad fan clutch or a cruddy radiator.
Certainly we here can't hope to change what you know already.
When well maintained, these cars, which were on the roads by the millions back in the sixties and seventies, did not overheat and their A/C blew ice cold. If something is not working right, it is probably because one or more parts need attention, and not because the entire thing needs to be replaced.
Some people just like to change things because they can, and you certainly have the right to do that, but I think it's important to understand why you are making changes and the effects they will have before you actually do it.
- Eric
You may just have a bad fan clutch or a cruddy radiator.
Certainly we here can't hope to change what you know already.
When well maintained, these cars, which were on the roads by the millions back in the sixties and seventies, did not overheat and their A/C blew ice cold. If something is not working right, it is probably because one or more parts need attention, and not because the entire thing needs to be replaced.
Some people just like to change things because they can, and you certainly have the right to do that, but I think it's important to understand why you are making changes and the effects they will have before you actually do it.
- Eric
This could be an issue:
Not all radiators are created equal. Some aftermarket radiators have fewer tubes per row and fewer cooling fins per inch than the originals, so even though you get a new radiator it may not have the cooling capacity necessary for the application.
Registered User
Joined: Oct 2010
Posts: 1,275
From: Boise ID
Agree with all the above.
This could be an issue:
Not all radiators are created equal. Some aftermarket radiators have fewer tubes per row and fewer cooling fins per inch than the originals, so even though you get a new radiator it may not have the cooling capacity necessary for the application.
This could be an issue:
Not all radiators are created equal. Some aftermarket radiators have fewer tubes per row and fewer cooling fins per inch than the originals, so even though you get a new radiator it may not have the cooling capacity necessary for the application.
Administrator
Joined: Oct 2009
Posts: 42,385
From: Poteau, Ok
The fans are not going to help your A/C issue. You need to see why it's not working at idle. If your not running hot in traffic with the A/C on, I'd leave well enough alone. Spend the money on fixing the A/C.
'87 Delta 88 Royale
Joined: Dec 2010
Posts: 2,514
From: Margate, England
Maybe you cold take a look at the A/C condenser, if the fins are in folded over they will impede airflow, both through the condenser and restricting the airflow through the coolant radiator.
As the Erics have said, (and in my opinion they both are well worth listening to), if the whole package is in good shape you don't need to fix anything
Roger.
As the Erics have said, (and in my opinion they both are well worth listening to), if the whole package is in good shape you don't need to fix anything
Roger.
Registered User
Joined: Jan 2014
Posts: 350
From: Camdenton, MO
The problem with AC weak and engine temps going up at idle is pretty common.. Not enough air flow to cool the rad and condenser. Electric fans will take care of this. The windstar fans will overwhelm that alternator, I think they're near 30 amps each.
In your situation, I would recommend what I did on my vette with a mechanical fan. Keep your fan, make sure the clutch is good. Add a generic puller that's actuated by an adjustable temp switch (Haywire) and/or the AC trinary switch (Vintage Air). On the fan, look at the amp draw, it's a pretty good indication of air flow. You can find them about $40 on ebay. Get one that pulls around 15 amps and you could probably keep your existing alternator if you don't add a lot of other stuff.
http://www.vintageair.com/2013catalo...ebpgs%2091.pdf
In your situation, I would recommend what I did on my vette with a mechanical fan. Keep your fan, make sure the clutch is good. Add a generic puller that's actuated by an adjustable temp switch (Haywire) and/or the AC trinary switch (Vintage Air). On the fan, look at the amp draw, it's a pretty good indication of air flow. You can find them about $40 on ebay. Get one that pulls around 15 amps and you could probably keep your existing alternator if you don't add a lot of other stuff.
http://www.vintageair.com/2013catalo...ebpgs%2091.pdf
Last edited by garys 68&72; May 23, 2014 at 06:51 AM.
'87 Delta 88 Royale
Joined: Dec 2010
Posts: 2,514
From: Margate, England
The problem with AC weak and engine temps going up at idle is pretty common.. Not enough air flow to cool the rad and condenser. Electric fans will take care of this. The windstar fans will overwhelm that alternator, I think they're near 30 amps each.
In your situation, I would recommend what I did on my vette with a mechanical fan. Keep your fan, make sure the clutch is good. Add a generic puller that's actuated by an adjustable temp switch (Haywire) and/or the AC trinary switch (Vintage Air). On the fan, look at the amp draw, it's a pretty good indication of air flow. You can find them about $40 on ebay. Get one that pulls around 15 amps and you could probably keep your existing alternator if you don't add a lot of other stuff.
http://www.vintageair.com/2013catalo...ebpgs%2091.pdf
In your situation, I would recommend what I did on my vette with a mechanical fan. Keep your fan, make sure the clutch is good. Add a generic puller that's actuated by an adjustable temp switch (Haywire) and/or the AC trinary switch (Vintage Air). On the fan, look at the amp draw, it's a pretty good indication of air flow. You can find them about $40 on ebay. Get one that pulls around 15 amps and you could probably keep your existing alternator if you don't add a lot of other stuff.
http://www.vintageair.com/2013catalo...ebpgs%2091.pdf
So why isn't there enough airflow at idle, why is the A/C weak?. Address these issues by finding out what is at fault, not treating the symptoms. You wouldn't fix gas mileage going down by installing a bigger fuel tank, so why go to the trouble and expense of increasing airflow when the proper fix is to find out why you need to increase it in the first place.
Roger.
Registered User
Joined: Jan 2014
Posts: 350
From: Camdenton, MO
Well the problem with my C3 vette is inadequate cooling in C3s. Very common in C3s.
Adding AC to a non AC car (not sure if that's the case of the OP) could be an issue if AC cars got improved cooling. Not uncommon in that era to have different cooling systems/radiator/fan clutches for AC/non-AC cars.
Old cooling systems get gunked up. A working electric fan solution might be cheaper/easier.
Adding AC to a non AC car (not sure if that's the case of the OP) could be an issue if AC cars got improved cooling. Not uncommon in that era to have different cooling systems/radiator/fan clutches for AC/non-AC cars.
Old cooling systems get gunked up. A working electric fan solution might be cheaper/easier.
So why isn't there enough airflow at idle, why is the A/C weak?. Address these issues by finding out what is at fault, not treating the symptoms. You wouldn't fix gas mileage going down by installing a bigger fuel tank, so why go to the trouble and expense of increasing airflow when the proper fix is to find out why you need to increase it in the first place.
Roger.
Roger.
'87 Delta 88 Royale
Joined: Dec 2010
Posts: 2,514
From: Margate, England
Well the problem with my C3 vette is inadequate cooling in C3s. Very common in C3s.
Adding AC to a non AC car (not sure if that's the case of the OP) could be an issue if AC cars got improved cooling. Not uncommon in that era to have different cooling systems/radiator/fan clutches for AC/non-AC cars.
Old cooling systems get gunked up. A working electric fan solution might be cheaper/easier.
Adding AC to a non AC car (not sure if that's the case of the OP) could be an issue if AC cars got improved cooling. Not uncommon in that era to have different cooling systems/radiator/fan clutches for AC/non-AC cars.
Old cooling systems get gunked up. A working electric fan solution might be cheaper/easier.
If the car has a cooling problem due to poor design, or the car has had extra demands added to its cooling system with aftermarket parts (or engine modifications) I agree with you. But a gunked up cooling system means some part of the engine isn't getting cooled properly, much better to clear it out thoroughly IMO.
Roger.
Registered User
Joined: Aug 2010
Posts: 3
There are a couple of consideration areas:
1. The stock fan with clutch on A/C cars was marginal, at best, in hot weather. (pre- 1966 cars)
2. The R134a refrigerant conversion will drive higher pressures in your A/C system, and reduce compressor life. (New condenser for R134a will help, but the A6 compressor was designed for R12, lower pressures.)
3. The A body cars, mine is 1965 442, were transitioning to the cross flow radiator (1966) for more radiator surface area.
4. The 1964 A Body had an even smaller (shorter) radiator.
5. The thermostatic fan clutch would leak the silicone fluid and just quit working or degrade performance without notice. Generally, the first indication was the antifreeze venting after driving in hot weather.
All of these issues can be helped with:
1. Coolant temp over 190 deg F, fan ON.
2. A/C compressor ON
While you are in there, install an internally regulated alternator, say 105 Amp. as those external regulators are a fire trap. And add a new AWG 6 gauge alternator conductor and in-line fuse.
One refinement I am considering is having the two electric fans have a slow speed for say 190, and high speed at 210, or separate fan operation temps.
The slippery slope here is to make these cars more reliable. looking at current engineering approaches to the vehicle.
1. The stock fan with clutch on A/C cars was marginal, at best, in hot weather. (pre- 1966 cars)
2. The R134a refrigerant conversion will drive higher pressures in your A/C system, and reduce compressor life. (New condenser for R134a will help, but the A6 compressor was designed for R12, lower pressures.)
3. The A body cars, mine is 1965 442, were transitioning to the cross flow radiator (1966) for more radiator surface area.
4. The 1964 A Body had an even smaller (shorter) radiator.
5. The thermostatic fan clutch would leak the silicone fluid and just quit working or degrade performance without notice. Generally, the first indication was the antifreeze venting after driving in hot weather.
All of these issues can be helped with:
1. Coolant temp over 190 deg F, fan ON.
2. A/C compressor ON
While you are in there, install an internally regulated alternator, say 105 Amp. as those external regulators are a fire trap. And add a new AWG 6 gauge alternator conductor and in-line fuse.
One refinement I am considering is having the two electric fans have a slow speed for say 190, and high speed at 210, or separate fan operation temps.
The slippery slope here is to make these cars more reliable. looking at current engineering approaches to the vehicle.
Registered User
Joined: Jan 2014
Posts: 350
From: Camdenton, MO
Alan,
The trinary switch is a better solution since it only turns the fan on when the AC refrigerant pressure gets high enough to require extra flow. That's especially true with a mechanical and electric fan. No point in running the electric if the mechanical is keeping up with the cooling requirements.
As for the dual speed with 2 electrical fans, that is how GM runs newer efi motors. Wiring diagram below.
The trinary switch is a better solution since it only turns the fan on when the AC refrigerant pressure gets high enough to require extra flow. That's especially true with a mechanical and electric fan. No point in running the electric if the mechanical is keeping up with the cooling requirements.
As for the dual speed with 2 electrical fans, that is how GM runs newer efi motors. Wiring diagram below.
Registered User
Joined: Aug 2010
Posts: 3
Excellent point Gary.
The switch would be added to bring newer technology to our older systems. And you will want to use a relay, as the pressure switch may not work long term with full fan amperage.
The other use of the Trinary pressure switch is to inhibit the compressor operation when low on refrigerant, protecting the compressor from burn out.
The switch would be added to bring newer technology to our older systems. And you will want to use a relay, as the pressure switch may not work long term with full fan amperage.
The other use of the Trinary pressure switch is to inhibit the compressor operation when low on refrigerant, protecting the compressor from burn out.
Last edited by Alan; May 27, 2014 at 11:23 AM.
Thread Starter
Registered User
Joined: Jan 2012
Posts: 585
From: Dallas, Tx
There are a couple of consideration areas:
1. The stock fan with clutch on A/C cars was marginal, at best, in hot weather. (pre- 1966 cars)
2. The R134a refrigerant conversion will drive higher pressures in your A/C system, and reduce compressor life. (New condenser for R134a will help, but the A6 compressor was designed for R12, lower pressures.)
3. The A body cars, mine is 1965 442, were transitioning to the cross flow radiator (1966) for more radiator surface area.
4. The 1964 A Body had an even smaller (shorter) radiator.
5. The thermostatic fan clutch would leak the silicone fluid and just quit working or degrade performance without notice. Generally, the first indication was the antifreeze venting after driving in hot weather.
All of these issues can be helped with:
1. Coolant temp over 190 deg F, fan ON.
2. A/C compressor ON
While you are in there, install an internally regulated alternator, say 105 Amp. as those external regulators are a fire trap. And add a new AWG 6 gauge alternator conductor and in-line fuse.
One refinement I am considering is having the two electric fans have a slow speed for say 190, and high speed at 210, or separate fan operation temps.
The slippery slope here is to make these cars more reliable. looking at current engineering approaches to the vehicle.
1. The stock fan with clutch on A/C cars was marginal, at best, in hot weather. (pre- 1966 cars)
2. The R134a refrigerant conversion will drive higher pressures in your A/C system, and reduce compressor life. (New condenser for R134a will help, but the A6 compressor was designed for R12, lower pressures.)
3. The A body cars, mine is 1965 442, were transitioning to the cross flow radiator (1966) for more radiator surface area.
4. The 1964 A Body had an even smaller (shorter) radiator.
5. The thermostatic fan clutch would leak the silicone fluid and just quit working or degrade performance without notice. Generally, the first indication was the antifreeze venting after driving in hot weather.
All of these issues can be helped with:
1. Coolant temp over 190 deg F, fan ON.
2. A/C compressor ON
While you are in there, install an internally regulated alternator, say 105 Amp. as those external regulators are a fire trap. And add a new AWG 6 gauge alternator conductor and in-line fuse.
One refinement I am considering is having the two electric fans have a slow speed for say 190, and high speed at 210, or separate fan operation temps.
The slippery slope here is to make these cars more reliable. looking at current engineering approaches to the vehicle.
Can you run a smaller compressor instead of the A6?
Registered User
Joined: Aug 2010
Posts: 3
Can you run a smaller compressor instead of the A6?
Alex - Keep in mind an air conditioning installation is a system. With all parts designed to work together.
The reason a car system is so complicated, is that the compressor speed (and refrigerant mass flow) is a function of engine RPM (also condenser airflow). At idle speed the BTU rating of the system is maybe 25-40%, because there is just not enough refrigerant circulating through the evalorator.
So back to your poor cooling at low speed, idle. The compressor is not turning fast enough to move enough refrigerant through the system. The question of different compressor is a side plot for this story.
Modern cars automatically go to recirculated air when the cooling system cannot meet load. Older cars it is a manual selection.
So what do you do? I can tell you what I do, in city traffic. I try to keep the engine in the 2,000 RPM range, by selecting a lower gear. And if stopped, I increase the RPM to around 1,500. And go to RECIRC on the selection.
As Gary correctly said, there are lot's of upgrades borrowing from current technology. For me the KISS principle applies. When the compressor is ON, so is my electric fan(s). I want all the refrigerant mass flow I can get. And my radiator temp sensor can turn the fan on after I have stopped the car engine to cool the engine compartment, helps stop carb flooding from perculation.
The old cars are fun, as long as you keep in mind, they were of simple design. When houses were not air conditioned. So any cooling was better than a hot home (or wife). And there were operating responsibilies for the operator. If the car ran hot, you shut off the A/C.
And we had names for cars. Why? Because they had personality querks. Would not start on first try, carb flooding when hot, balky when cold, points need adjusting, on and on. With fuel injection, the cars run until out of gas. No DRAMA.
Alex - Keep in mind an air conditioning installation is a system. With all parts designed to work together.
The reason a car system is so complicated, is that the compressor speed (and refrigerant mass flow) is a function of engine RPM (also condenser airflow). At idle speed the BTU rating of the system is maybe 25-40%, because there is just not enough refrigerant circulating through the evalorator.
So back to your poor cooling at low speed, idle. The compressor is not turning fast enough to move enough refrigerant through the system. The question of different compressor is a side plot for this story.
Modern cars automatically go to recirculated air when the cooling system cannot meet load. Older cars it is a manual selection.
So what do you do? I can tell you what I do, in city traffic. I try to keep the engine in the 2,000 RPM range, by selecting a lower gear. And if stopped, I increase the RPM to around 1,500. And go to RECIRC on the selection.
As Gary correctly said, there are lot's of upgrades borrowing from current technology. For me the KISS principle applies. When the compressor is ON, so is my electric fan(s). I want all the refrigerant mass flow I can get. And my radiator temp sensor can turn the fan on after I have stopped the car engine to cool the engine compartment, helps stop carb flooding from perculation.
The old cars are fun, as long as you keep in mind, they were of simple design. When houses were not air conditioned. So any cooling was better than a hot home (or wife). And there were operating responsibilies for the operator. If the car ran hot, you shut off the A/C.
And we had names for cars. Why? Because they had personality querks. Would not start on first try, carb flooding when hot, balky when cold, points need adjusting, on and on. With fuel injection, the cars run until out of gas. No DRAMA.
Last edited by Alan; May 30, 2014 at 04:06 AM.
Registered User
Joined: Aug 2006
Posts: 3,145
From: Far Northeast Philadelphia, PA
AC blowing cold on the highway, then hot in traffic is another issue altogether. An electric fan is not going to help that issue.
A/C could be overcharged.
Valve could be froze up
Condensor could be shot or all crudded up
Could be a sensor or relay.
I'm having the same issues with my Volvo's A/C right now. A/C problems are pretty much the same no matter what kind of car it is
A/C could be overcharged.
Valve could be froze up
Condensor could be shot or all crudded up
Could be a sensor or relay.
I'm having the same issues with my Volvo's A/C right now. A/C problems are pretty much the same no matter what kind of car it is
Registered User
Joined: Jan 2014
Posts: 350
From: Camdenton, MO
Ok, a little refresher on the OP.
He's had issues with stock system, he's installing vintage air. I'm assuming Sanden, new condenser, evaporator, etc.
The VA system run recirculate 100% of the time, so that's out.
VA specifies not to run anything off the AC request signal, so full time AC with compressor is a no go.
The addition of an electric fan is pretty common with AC since they generate more heat and at idle neither compressors nor mechanical fans are optimal.
I'm just relaying what worked very well with my Vintage AC with mechanical fan, aux electric on trinary switch.
He's had issues with stock system, he's installing vintage air. I'm assuming Sanden, new condenser, evaporator, etc.
The VA system run recirculate 100% of the time, so that's out.
VA specifies not to run anything off the AC request signal, so full time AC with compressor is a no go.
The addition of an electric fan is pretty common with AC since they generate more heat and at idle neither compressors nor mechanical fans are optimal.
I'm just relaying what worked very well with my Vintage AC with mechanical fan, aux electric on trinary switch.
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