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A few questions here please..Anybody have pics or info of non ac 1970 cars showing how deep the fan goes into the shroud along with how far the fan actually is from the radiator? I ask because everything I have read is the fan should be roughly an inch from the fan tips to the radiator along with the fan should be half in the shroud and half way out for maximum air volume.
On my 1970 car, non ac it has the 3 core radiator and the second owner finagled a shroud on by securing bolts on the bottom side of a non shroud top plate. The fan sits roughly two inches inside the shroud, the fan tips are roughly 1.5 on top from radiator and the bottom is around 3 inches.. The shroud on the bottom and top almost touch the fan tips on the side of the shroud. You got a good 2 1/2 inches so I don’t know if it’s an incorrect shroud or what? However the radiator sits a little bit angled in there it’s a replacement brass radiator, so I’m just trying to get maximum cooling on this thing as in Florida in the summer the car driving down the road still at 205, at idle will slowly climb to 225.. trying to get to a 190 - 195 on cruising and 205-210 at stop light idle..
I am thinking of trying a 7 blade 19” fan to see if that helps..Any suggestions or photos of factory 70 cars?
As you can see in first pic the gap is huge at top of radiator to the core support, the fan is deep into the shroud and the radiator that is a brass replacement actually sits a bit angled..I am thinking all this is causing some flow issues as when thermostat engages the top radiator hose is maybe 5 degrees hotter than the lower hose..
I would think it would cool sufficiently since that is the way the factory designed it. I believe the radiator sitting at a slight angle is correct.
If it were my car I would return everything as stock and go from there. There are many factors that can cause overheating. From your description I would start with the fan clutch. Good luck.
I would think it would cool sufficiently since that is the way the factory designed it. I believe the radiator sitting at a slight angle is correct.
If it were my car I would return everything as stock and go from there. There are many factors that can cause overheating. From your description I would start with the fan clutch. Good luck.
Don W
Thanks, fan clutch new, radiator new. Water pump and thermostat new...I may remove shroud and see how it acts without-since that was factory..maybe the way the fan is sitting so deep into the shroud is debilitating air flow..
...maybe the way the fan is sitting so deep into the shroud is debilitating air flow…
Andy, when the factory engineers designed these systems, they found that for maximum airflow, the fan blades needed to be centered on the edge of the shroud opening (fan would be half-in the shroud and half-out of the shroud).
Interesting the factory didn’t use a shroud on all 455’s and offered so many combinations that make up the cooling system in 70. Have noticed most manufacturers have the fan blades sit half inside and the other half out of the fan like you mentioned. Do you have the correct water pump and pulleys that were used with a clutch fan and shroud?
Interesting the factory didn’t use a shroud on all 455’s and offered so many combinations that make up the cooling system in 70. Have noticed most manufacturers have the fan blades sit half inside and the other half out of the fan like you mentioned. Do you have the correct water pump and pulleys that were used with a clutch fan and shroud?
Dustin
Dustin,
I have the 404847 waterpump, got it from Vader, he said it was correct.. does anyone know if the HD cooling v2 waterpump was different? As for the pulleys That shouldn’t make any difference on a non ac car and a non ac car with HD cooling like the 3.91 geared cars that got HD..
I am looking to see if anyone with a 70 car has a pic of there fan and how deep it goes into the shroud.. I’m starting to think that the top plate with the heavy duty cooling positions that shroud differently than my factory three-core top plate that’s not really supposed to have a shroud..
Last edited by Andy; March 31st, 2023 at 09:47 AM.
I would think it would cool sufficiently since that is the way the factory designed it. I believe the radiator sitting at a slight angle is correct.
If it were my car I would return everything as stock and go from there. There are many factors that can cause overheating. From your description I would start with the fan clutch. Good luck.
Don W
I am starting to think the newer fan clutch may be the problem, i certainly don’t here or feel a sudden rush of air of roar like the fan clutch is kicking on..Did 455 car’s use the heavy duty fan clutch?
Have you determined the actual running temperature? You will find the 68 up bbo engines run @ a higher temperature than the early bbo.
Running temp is around 195-205, idling it goes to 230, may go higher but I shut it off..people talk about hearing the fan clutch kick in I don’t feel or hear that when idling and warming up.. its a new fan clutch..as stated fan sets deep into the shroud as my car was factory no shroud and the second owner made a shroud work with the 3 core top plate. Usually the top hose will be at least 15-20 degrees hotter than bottom hose showing coolant is actually getting cooled off running thru the radiator..mine may have a 7-10 degree difference..radiator new brass 3 core..thinking about trying a 7 blade fan to see if that will help at idle as well as maybe try a heavy duty clutch fan so it spins at lower temps..Thats all I can figure..if that doesn’t work maybe go to a 2 core be cool big aluminum radiator..hate to keep throwing money at this
Also, fan will help your idle. If you can keep it at idle cooler than going down the road, the fan system is working. Going down the highway hot is coolant flow, not airflow, as the wind is more than your fan will give it. In other words, I think you have a large problem (fan) and a small problem (slightly underperforming radiator.). Please determine if that is original radiator. It could be boiled or recored as well as fan work.
I put a NOS BBC 3 row in my 72 Monte Carlo with 350 SBC last summer. Car would run very hot on the road, and I bandaid'ed it with a 160 deg superstat about ten years ago. Now, with awesome radiator and 185 superstat, it sits right there all day, even when I had an intake bolt leak keeping it from pressurizing (which is now also fixed.) Point being, it cooled down well at idle, so my fan and shroud and clutch were ok. 210 on the road in FL is ok, but not great. Heating up at idle is the more critical, as you have noted.
are you saying wrong 6 blade fan or wrong fan clutch?
Maybe both. I think you should check your part numbers. Please forgive the crappy pictures, but this is the closest I have of photos already taken of my H/O with 455, 4 row, shroud, clutch, and fan.
Also, fan will help your idle. If you can keep it at idle cooler than going down the road, the fan system is working. Going down the highway hot is coolant flow, not airflow, as the wind is more than your fan will give it. In other words, I think you have a large problem (fan) and a small problem (slightly underperforming radiator.). Please determine if that is original radiator. It could be boiled or recored as well as fan work.
I put a NOS BBC 3 row in my 72 Monte Carlo with 350 SBC last summer. Car would run very hot on the road, and I bandaid'ed it with a 160 deg superstat about ten years ago. Now, with awesome radiator and 185 superstat, it sits right there all day, even when I had an intake bolt leak keeping it from pressurizing (which is now also fixed.) Point being, it cooled down well at idle, so my fan and shroud and clutch were ok. 210 on the road in FL is ok, but not great. Heating up at idle is the more critical, as you have noted.
Its a new brass 3 core radiator..everything I know about fans and shrouds says this fan is setting way to deep into the shroud not maximizing air flow, as stated the top plate is a non shroud plate thats been modified to attach a shroud..Thinking on trying a 4 core top plate that came factory with heavy duty cooling and shroud..before I had the original block put back in the car I was using the factory temp guage and it always showed in the middle of high low on guage..I just put the original block with a rebuild back in and hooked up a new aftermarket guage to verify temps..Hell it may have ran that warm the whole time and I didn’t know it..just want to get it right..
Maybe both. I think you should check your part numbers. Please forgive the crappy pictures, but this is the closest I have of photos already taken of my H/O with 455, 4 row, shroud, clutch, and fan.
Thank you for the pics..i will post once I figure it out..I am going to start at the beginning, remove the shroud, check the part number on the fan, check and see if the clutch fan is a heavy duty or what and then see what happens with no shroud and troubleshoot from there. Start at the beginning and take one fix at a time. Much appreciated
Thanks..I think its the top plate positions the shroud correctly, mine is a 3 core top plate with a shroud made to work..i got a 4 core top plate coming, hopefully that will line it up correctly and give me better at idle cooling..much appreciated
March 30th, 2023, 02:25 PM
