Blown 440 Duster - Cooling System Results

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70Duster440

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So I've been sweating how I was going to cool this thing since there's zero room for a fan between the blower drive and the radiator (any radiator). So here's what I did and the results (so far) :thumbrig:

Started with a Summit 2 row, 27"x19" crossflow radiator ( SUM-381428 ) which fits the 22" core support opening perfectly. Had some brackets TIG'd onto the tanks and had to create new mounting points on the core support.

Dayco molded lower rad hose 70592 (one end trimmed). Dayco molded upper hose 71654 (one end trimmed) to clear the blower drive.

Dayco lower 70592.jpg

Dayco upper 71654.jpg


New engine has a Milodon water pump and high flow 180* stat.

Early Dusters have such a snub nose there's very little room between the core support and grille for a fan. Ordered the most powerful 16" Spal Pusher fan I could get. Motor takes up a lot of space. Cut a section out of the grill support and added hoop to go around the motor and add strength back to the support.

mod brace for fan install.jpg

mod brace for fan install 2.jpg

painted modified brace.jpg


Mounted the fan using the old radiator mounting holes.

installed fan and painted brace.jpg


The design of the radiator creates a 1" gap between the bottom of the core support and the radiator core. Since air would follow the path of least resistance it would just flow around the core instead of through it. I added a rubber seal to the bottom of the radiator to fill the gap. It's a heavy rubber seal intended for the bottom of garage doors. It fills the space perfectly, and even provided a seal in two places. Aluminum trim fills the void at the top of the core support.

add rubber to radiator.jpg


The fan is loud but it moves quite a bit of air. I currently have it wired to run continuously with the key on rather than thermostatic control.

final install 01.jpg

final install 02.jpg

final install 03.jpg


:burnout: Took it for it's first road test this evening. Ran between 165-180* on the highway and cruising around town. Sitting for several minutes it would creep a little higher. Overall, I'm surprised and pleased. I was afraid it would run hot. :cheers:
 
intresting radiator,,,,,,car looks great,,,,

the how hot factor on a blower motor depends on a few things besides the fan and radiator,,,,cam center line,,,,blower drive ratio,,,air fuel mixture,,,

believe it or not i have 3 inch blower belt in an early A,, with enough room for a mechanical water pump mounted fan,,,,a stand by elec fan in front,,,and a 4 row factory style radiator,,,160 high flow stat,,,its runs 178 on the high way,,,182 ish around town,,,and in the winter wont hardly get up past 150....
 

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the how hot factor on a blower motor depends on a few things besides the fan and radiator,,,,cam center line,,,,blower drive ratio,,,air fuel mixture,,,

believe it or not i have 3 inch blower belt in an early A,, with enough room for a mechanical water pump mounted fan,,,,a stand by elec fan in front,,,and a 4 row factory style radiator,,,160 high flow stat,,,its runs 178 on the high way,,,182 ish around town,,,and in the winter wont hardly get up past 150....

I would much rather have run a mechanical fan. Had to ditch power steering just to get the clearance I have (about 1"). Wonder what the overall difference in length between a SB and BB is.

I'm running a little wider than typical LSA, about 7% OD, and I'm not exactly sure where my AF mix is right now - though I have it jetted on the rich side for safety.
 
That is great! What were the ambient outside temps? I know mine is fine at or below 90 degrees but when the outside temp goes up so does my gauge!
 
That is great! What were the ambient outside temps? I know mine is fine at or below 90 degrees but when the outside temp goes up so does my gauge!

Been in the 90's around here during the day. Probably 80 something that evening. Don't think I'll be doing any cruising in 90+ weather anyway - too miserable. I expect it will run a little cooler as the breaks in too.
 
I would much rather have run a mechanical fan. Had to ditch power steering just to get the clearance I have (about 1"). Wonder what the overall difference in length between a SB and BB is.

I'm running a little wider than typical LSA, about 7% OD, and I'm not exactly sure where my AF mix is right now - though I have it jetted on the rich side for safety.

hard to believe you had to give up power steering for clearance up front,,as you can see i have a 3 inch blower belt in an early A body,,,if you look close you can see i trimmed off the lip of the radiator support just in front of the rad,,,moved the mounting brackets towards the motor to move the rad forward to clear the 3 inch belt,,then a large elecric fan in front just incase,,,i may look in to that same rad u have,,,

if your running 7% over drive, ill assume you have a 6.71 blower not an 8.71, your tempts are doing fine if your over driving the blower,,,you have to over drive a blower on a big block if its a 6.71 to make any power and over driving makes HEAT,,, im 6% under driven on a 340 and make 13 pounds of boost,, are your carbs converted to blower carbs ???? or ddi you buy blower carbs out of the box ??? my carbs are 650,s and have been re worked by a carb shop that specializes in blower motors,,made a world of difference,,,fires right up and idels ,dont have to wait for the blower to build heat,,,all the passages in the metering blocks have been drilled out and different jet sizes put in for differnt RPM levels,,,chock horns milled off,,venturies have been smoothed out,,thinned throttle blades and 4 corner idel,, this they now flow 862 CFM each,,not 650CFM,,, this was all done before blower carbs were available out of the box,,im looking in to injection now,,,these carbs will be for sale,,,,,
 
hard to believe you had to give up power steering for clearance up front,,as you can see i have a 3 inch blower belt in an early A body,,,if you look close you can see i trimmed off the lip of the radiator support just in front of the rad,,,moved the mounting brackets towards the motor to move the rad forward to clear the 3 inch belt,,then a large elecric fan in front just incase,,,i may look in to that same rad u have,,,

if your running 7% over drive, ill assume you have a 6.71 blower not an 8.71, your tempts are doing fine if your over driving the blower,,,you have to over drive a blower on a big block if its a 6.71 to make any power and over driving makes HEAT,,, im 6% under driven on a 340 and make 13 pounds of boost,, are your carbs converted to blower carbs ???? or ddi you buy blower carbs out of the box ??? my carbs are 650,s and have been re worked by a carb shop that specializes in blower motors,,made a world of difference,,,fires right up and idels ,dont have to wait for the blower to build heat,,,all the passages in the metering blocks have been drilled out and different jet sizes put in for differnt RPM levels,,,chock horns milled off,,venturies have been smoothed out,,thinned throttle blades and 4 corner idel,, this they now flow 862 CFM each,,not 650CFM,,, this was all done before blower carbs were available out of the box,,im looking in to injection now,,,these carbs will be for sale,,,,,


Like I said, drive clearance may be the difference between a small block and big block. If I'd kept the PS I'd have about 1/4" between the drive and radiator core. My core is 2.25" inches thick (tanks are thicker) and if it had been a down flow with those clearances you wouldn't have been able to get it in and out because of the tanks.

An 8-71 would have been more efficient but there's a whole story/saga behind who I purchased it through. And actually, an 8-71 would have created issues elsewhere so I'm happy. For a street car, it'll do fine.

I went with 750 Edelbrocks for a couple reasons: Cost, I wanted a little more retro look, and inline linkage instead of side saddle. I did my own mods on them for blower use and so far I have no complaints. If I were racing I would have gone with Holleys.

The original plan was to do all this on a "budget" - if there is such a thing. And, of course, it ballooned out of control.

It's is building pressure in the blower gear case and forcing lube out so I'm addressing that next.
 
looks like you have it covered,, ilike the carter carb look better my self,,but the holleys are what i had

forcing lube out ?? of the gear case ?? do you have a bleader on the top of the case???
 
I'm adding a pressure relief valve today when it arrives. The blower "expert" that I got the bulk of the setup from didn't think one would be needed.
 
I'm adding a pressure relief valve today when it arrives. The blower "expert" that I got the bulk of the setup from didn't think one would be needed.

i have never ran with out the relief valve so i dont knwo for sure ,,but i never had that problem either,,
 
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