New A/C causing overheating (w/pics)
Thread Starter
2nd Gear Member
Joined: May 2011
Posts: 183
From: NY
New A/C causing overheating (w/pics)
So I had a full Old Air kit added to my 68 and now since the condenser mounts in front of the rad (champion 20inch 3 row aluminum) I am getting insufficient airflow with my ebay special fan. I have already ordered a high powered Spal puller but I dont know if that will be enough? I get in a lot of traffic in the NYC area and we are currently in the 90s and without venting I get to H fairly quickly.
Questions:
1) Should I add a 16in pusher in front of my condenser or move it outward and get a puller between it and the rad?
2) Is it likely I will have to go back to a mechanical fan?
3) Should I upgrade to a 4 row rad (or another brand)?
Pics (recent coolant overflow that needs cleaning)
https://picasaweb.google.com/W.Casag...eat=directlink
Questions:
1) Should I add a 16in pusher in front of my condenser or move it outward and get a puller between it and the rad?
2) Is it likely I will have to go back to a mechanical fan?
3) Should I upgrade to a 4 row rad (or another brand)?
Pics (recent coolant overflow that needs cleaning)
https://picasaweb.google.com/W.Casag...eat=directlink
6th Gear Member
Joined: Jan 2007
Posts: 5,469
From: AR
So I had a full Old Air kit added to my 68 and now since the condenser mounts in front of the rad (champion 20inch 3 row aluminum) I am getting insufficient airflow with my ebay special fan. I have already ordered a high powered Spal puller but I dont know if that will be enough? I get in a lot of traffic in the NYC area and we are currently in the 90s and without venting I get to H fairly quickly.
Questions:
1) Should I add a 16in pusher in front of my condenser or move it outward and get a puller between it and the rad?
2) Is it likely I will have to go back to a mechanical fan?
3) Should I upgrade to a 4 row rad (or another brand)?
Pics (recent coolant overflow that needs cleaning)
https://picasaweb.google.com/W.Casag...eat=directlink
Questions:
1) Should I add a 16in pusher in front of my condenser or move it outward and get a puller between it and the rad?
2) Is it likely I will have to go back to a mechanical fan?
3) Should I upgrade to a 4 row rad (or another brand)?
Pics (recent coolant overflow that needs cleaning)
https://picasaweb.google.com/W.Casag...eat=directlink
Thread Starter
2nd Gear Member
Joined: May 2011
Posts: 183
From: NY
Since most of the overheating occurs at stop I am reluctant to go back to a drive fan since my stock one wasnt effective in traffic.
Thread Starter
2nd Gear Member
Joined: May 2011
Posts: 183
From: NY
It would be a blessing if the gauges were wrong but the garage did check the temp after taking it for a spin and it was running warm. For the original gauges does anyone know what H is suppose to represent. I want to install a oil/volt/temp gauge cluster but I dont have a great spot.
2nd Gear Member
Joined: Aug 2009
Posts: 475
From: Nebraska
What do you have for a fan currently? And does it have a shroud that completly covers the radiator?
You said that your antifreeze was cruddy, how cruddy? A few small chunks of crud or brown antifreeze cruddy?
How old is the radiator?
What do you have for a thermostat?
Your pic link isnt working for me so i cant see what you have currently. A big thing that people skip is having a good shroud. It will force the fan to pull air through the entire radiator rather than around it and only cooling a smaller portion of the radiator.
You said that your antifreeze was cruddy, how cruddy? A few small chunks of crud or brown antifreeze cruddy?
How old is the radiator?
What do you have for a thermostat?
Your pic link isnt working for me so i cant see what you have currently. A big thing that people skip is having a good shroud. It will force the fan to pull air through the entire radiator rather than around it and only cooling a smaller portion of the radiator.
Thread Starter
2nd Gear Member
Joined: May 2011
Posts: 183
From: NY
fan - ebay 16 in - being replaced by spal 16 meduim profile puller (already shrouded)
coolant - fully flushed (chemically and machine flushed) - 50/50mix and adding water wetter next time
radiator - brand new 20in 3 core aluminum champion radiator
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT
try the link for the pics again
coolant - fully flushed (chemically and machine flushed) - 50/50mix and adding water wetter next time
radiator - brand new 20in 3 core aluminum champion radiator
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT
try the link for the pics again
2nd Gear Member
Joined: Jun 2011
Posts: 486
From: Texas
I can't get to your pics and have no desire to sign up at picasa, so I'll go on the vague picture you painted in words.
In all probability, you are suffering most from a lack of airflow through the entire core. You didn't mention a fan shroud, so I take it you ditched the OE shroud, if any was present, when you installed the Ebay fan.
Betting that this fan doesn't cover the entire core from corner to corner, you are only getting air flow through the portion directly in front of the core. It won't matter if you buy a better fan, if you install it the same way.
The best possible install requires that you have a 100% coverage of the core with a good shroud that is sealed to the core and that the core is sealed to the radiator support. By "sealed", I mean very tightly mounted, no gaps over about 3/16". The best shroud touches the radiator. Then the fan must be very close to the shroud at the tips of the fan blades.
The reason for a total cover shroud is that the fan doesn't really pull air through the core. It actually needs to create a low pressure area across the entire core, so that the higher pressure air on the front will come through as a matter of physics. The reason the radiator needs to be close to the core support is to ensure that hot air from the engine bay does not recirculate back to the front side.
If you are lacking for a good shroud, find a restaraunt supply and pick up an aluminum cookie sheet (commercial grade) the same size as your core. It will have nice rolled edges and be heavy enough to attach mounting tabs to. Mark the center of your fan placement and use a compass or a string to mark a circle the same size as your fans outer edges. Cut that out and mount the fan on the back of this and it will be suspended a half inch or so from your core, with a cavity that it can draw air on the entire core, not just the space the fan covers.
Also think about how a late model works. Two fans, one on the t-stat as needed, one on full time with the A/C, on a relay. The A/C condensor doesn't really impede air flow. It raises the temp of the air before it gets to the radiator. Move enough air through the combination and you will overcome that factor.
In all probability, you are suffering most from a lack of airflow through the entire core. You didn't mention a fan shroud, so I take it you ditched the OE shroud, if any was present, when you installed the Ebay fan.
Betting that this fan doesn't cover the entire core from corner to corner, you are only getting air flow through the portion directly in front of the core. It won't matter if you buy a better fan, if you install it the same way.
The best possible install requires that you have a 100% coverage of the core with a good shroud that is sealed to the core and that the core is sealed to the radiator support. By "sealed", I mean very tightly mounted, no gaps over about 3/16". The best shroud touches the radiator. Then the fan must be very close to the shroud at the tips of the fan blades.
The reason for a total cover shroud is that the fan doesn't really pull air through the core. It actually needs to create a low pressure area across the entire core, so that the higher pressure air on the front will come through as a matter of physics. The reason the radiator needs to be close to the core support is to ensure that hot air from the engine bay does not recirculate back to the front side.
If you are lacking for a good shroud, find a restaraunt supply and pick up an aluminum cookie sheet (commercial grade) the same size as your core. It will have nice rolled edges and be heavy enough to attach mounting tabs to. Mark the center of your fan placement and use a compass or a string to mark a circle the same size as your fans outer edges. Cut that out and mount the fan on the back of this and it will be suspended a half inch or so from your core, with a cavity that it can draw air on the entire core, not just the space the fan covers.
Also think about how a late model works. Two fans, one on the t-stat as needed, one on full time with the A/C, on a relay. The A/C condensor doesn't really impede air flow. It raises the temp of the air before it gets to the radiator. Move enough air through the combination and you will overcome that factor.
Last edited by scottybaccus; Jul 18, 2011 at 11:16 AM.
Thread Starter
2nd Gear Member
Joined: May 2011
Posts: 183
From: NY
You dont have to sign up for picasa...I reset to a new link that should be viewable on any browswer
https://picasaweb.google.com/W.Casag...eat=directlink
As you can see I have a shroud so that is not the issue.
To be more specific, how do people deal with reduced airflow since the condenser sits in front of the radiator?
Also, how will I know if my mixture is running to rich?
https://picasaweb.google.com/W.Casag...eat=directlink
As you can see I have a shroud so that is not the issue.
To be more specific, how do people deal with reduced airflow since the condenser sits in front of the radiator?
Also, how will I know if my mixture is running to rich?