Glenwood
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I thought I'd post about the struggle I've had with cooling this 426ci 64 Dodge. Since the motor was rebuilt from a 413 block, it tended to heat up on really hot days. An unusual story here I know! This is an account of improvements I made that seemed to have fixed the problem.
The motor went through a number of upgrades over the last couple of years with things like aluminum heads, roller rockers, pertronix ignition, FBO adv plate, carb swap from 750 eddy to a holley 670, dougs cermaic headers and so on. The underhood heat was incredible during the hotter days and the temperature really rises faster with the hood closed.
The cooling system consisted of a summit cast hv pump, 22" OER rad which has 2x1" tubes, eventually adding a custom shroud with a 7-blade 18" mopar fan that is 2" deep. Regardless of where the fan was position, it seemed like it wasn't drawing enough air. So on went a derale 16" elec 2-speed pusher fan, which of course required a new power master alternator, regulator and properly sized wiring , which made a huge difference with idle voltage.
Still, I don't like having to worry about temperatures and possible over heating. This past July was unbearably hot, so I could not even be bothered to drive it much. The car is running well but the temps climb while idling, even out of the sun in the shop. The electric fan has to be on full to make a difference but does work.
Looking at flow in the rad when the 180 stat opened, there was hardly a ripple with the summit high volume pump. I've had it out to inspect and I don't believe there is anything wrong with it. Ordered and installed a new alum milodon hv pump after reading some reviews about flow at low rpm. The flow improvement was dramatic and slowed the rate of heat rise, but still climbed to over 220. A smaller pulley might have helped with the other pump and fan, but can't find one.
I then ordered a new derale 17" mechanical fan, hoping it would pull more air. Unfortunately it didn't and its depth is also 2", the same as the 7-blade I have.
I had suspected from the beginning that the 22" rad was a tad too small for this motor's cooling requirements and although more airflow would have helped, There is not enough room for electric puller fans or a clutch fan, even the shallow clutch type. Enough is enough, so I ordered a new cold case 26" rad with 2x1.25" tubes and a new shroud meant for B & E bodies.
The installation into the 64 is snug since it was never designed for anything beyond a 22". A little trimming of the mounting ears and I was able to get it in place. I decided not to trim the opening yet, so I could see how it cools with the extra capacity. Thankfully the rad hoses still lined up as do the transmission lines with a little tweaking. The 20" dia. shroud centered with the fan horizontally, but it a tad high vertically. Still lots of room for an 18" fan. The cold case mounting ears for the shroud are flush with the core and does not permit the shroud to fit tightly around the core unfortunately, leaving a 1/4" gap along the top and bottom. I'll seal it with something if necessary.
With a mix of more water and less antifreeze, the car was started using the 7-blade fan. Heat rise was much slower and seemed to top off around 210 or so. Still too hot for my liking. I tried to move the fan back, changing the spacer from 1" to 1/2". It made it worse. I richened up the idle screw 1/2 turn in case I have it too lean, but did not see an improvement although the #5 & 8 header tubes started to cool down a bit more from about 570 degrees to just over 500. Still 100 degrees hotter than the other cylinders. I suspect that intake runner that feeds both is running lean, but I don't know why yet.
I opted to try a factory flex fan I have which has quite a pitch being 3" deep. I'm aware of the risk with these things, but I wanted to see if airflow would improve and if it made a difference. Pics to follow...
The motor went through a number of upgrades over the last couple of years with things like aluminum heads, roller rockers, pertronix ignition, FBO adv plate, carb swap from 750 eddy to a holley 670, dougs cermaic headers and so on. The underhood heat was incredible during the hotter days and the temperature really rises faster with the hood closed.
The cooling system consisted of a summit cast hv pump, 22" OER rad which has 2x1" tubes, eventually adding a custom shroud with a 7-blade 18" mopar fan that is 2" deep. Regardless of where the fan was position, it seemed like it wasn't drawing enough air. So on went a derale 16" elec 2-speed pusher fan, which of course required a new power master alternator, regulator and properly sized wiring , which made a huge difference with idle voltage.
Still, I don't like having to worry about temperatures and possible over heating. This past July was unbearably hot, so I could not even be bothered to drive it much. The car is running well but the temps climb while idling, even out of the sun in the shop. The electric fan has to be on full to make a difference but does work.
Looking at flow in the rad when the 180 stat opened, there was hardly a ripple with the summit high volume pump. I've had it out to inspect and I don't believe there is anything wrong with it. Ordered and installed a new alum milodon hv pump after reading some reviews about flow at low rpm. The flow improvement was dramatic and slowed the rate of heat rise, but still climbed to over 220. A smaller pulley might have helped with the other pump and fan, but can't find one.
I then ordered a new derale 17" mechanical fan, hoping it would pull more air. Unfortunately it didn't and its depth is also 2", the same as the 7-blade I have.
I had suspected from the beginning that the 22" rad was a tad too small for this motor's cooling requirements and although more airflow would have helped, There is not enough room for electric puller fans or a clutch fan, even the shallow clutch type. Enough is enough, so I ordered a new cold case 26" rad with 2x1.25" tubes and a new shroud meant for B & E bodies.
The installation into the 64 is snug since it was never designed for anything beyond a 22". A little trimming of the mounting ears and I was able to get it in place. I decided not to trim the opening yet, so I could see how it cools with the extra capacity. Thankfully the rad hoses still lined up as do the transmission lines with a little tweaking. The 20" dia. shroud centered with the fan horizontally, but it a tad high vertically. Still lots of room for an 18" fan. The cold case mounting ears for the shroud are flush with the core and does not permit the shroud to fit tightly around the core unfortunately, leaving a 1/4" gap along the top and bottom. I'll seal it with something if necessary.
With a mix of more water and less antifreeze, the car was started using the 7-blade fan. Heat rise was much slower and seemed to top off around 210 or so. Still too hot for my liking. I tried to move the fan back, changing the spacer from 1" to 1/2". It made it worse. I richened up the idle screw 1/2 turn in case I have it too lean, but did not see an improvement although the #5 & 8 header tubes started to cool down a bit more from about 570 degrees to just over 500. Still 100 degrees hotter than the other cylinders. I suspect that intake runner that feeds both is running lean, but I don't know why yet.
I opted to try a factory flex fan I have which has quite a pitch being 3" deep. I'm aware of the risk with these things, but I wanted to see if airflow would improve and if it made a difference. Pics to follow...
