DeWitt radiators: Do you need or just want?
01-12-2011, 09:42 PM
#21
Safety Car
Mine is not in the car yet but I ordered one with the electric fan set up, once it arrived I opened up the box to look it over and man what a beautiful piece it is. Well made and looks like it could keep a funny car cool running in the desert.
If it works half as good as it looks I'll be pleased.
If it works half as good as it looks I'll be pleased.
01-13-2011, 12:22 PM
#22
My original copper/brass radiator was in good condition, but my new (409 SBC) engine was overheating. It was clearly a case of inadequate cooling capacity- I was fine up to 60 MPH, but when the engine was pushed a little harder- temperatures would creep up and run away. A brand new copper/brass, of visually identical construction, behaved in exactly the same way- stable at 60 MPH, became unstable and ran away at anything 62 MPH or over.
I tried a new severe duty fan clutch, it didn't have any effect on the highway- as we would expect, since the fan really is intended to work at slower speeds but not so much on the highway.
I adjusted timing and A/F mixture all over the map, but the results on the highway were virtually unchanged except for MPG and acceleration performance.
I eventually realized that given how the speed was such an overriding factor that my engine was conducting more heat into the coolant because the new engine had aluminum heads rather than iron (aluminum has a far higher thermal conductivity coefficient than iron) so even at cruise when the same power is being generated as the old engine, more heat is conducted into the coolant rather than just expelled through the exhaust port.
Keep in mind that GM resorted to using aluminum radiators in big block and high performance C3's when they were in production. They were eliminated when the high horsepower engines went away.
I ordered a new radiator from Tom, and it completely solved the problem. Tuning was a breeze (both carburetor and timing) and I had the freedom to tune for performance and MPG, without a worry about overheating (or the resulting detonation). I'm a very happy DeWitts customer.
I tried a new severe duty fan clutch, it didn't have any effect on the highway- as we would expect, since the fan really is intended to work at slower speeds but not so much on the highway.
I adjusted timing and A/F mixture all over the map, but the results on the highway were virtually unchanged except for MPG and acceleration performance.
I eventually realized that given how the speed was such an overriding factor that my engine was conducting more heat into the coolant because the new engine had aluminum heads rather than iron (aluminum has a far higher thermal conductivity coefficient than iron) so even at cruise when the same power is being generated as the old engine, more heat is conducted into the coolant rather than just expelled through the exhaust port.
Keep in mind that GM resorted to using aluminum radiators in big block and high performance C3's when they were in production. They were eliminated when the high horsepower engines went away.
I ordered a new radiator from Tom, and it completely solved the problem. Tuning was a breeze (both carburetor and timing) and I had the freedom to tune for performance and MPG, without a worry about overheating (or the resulting detonation). I'm a very happy DeWitts customer.
01-13-2011, 09:33 PM
#24
Race Director
Member Since: Mar 2003
Location: Eustis ( Area 51 Bat Cave ) Fl
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Quote:
Originally Posted by wcsinx
Not saying Dewitts isn't a good piece, but you can get aluminum C3 rads for much less (~1/4th) from other vendors.
I reserched all the Fleabay and net units,
NONE are in par with what Dewitts offers...will they cool as good? I do not know I havent tested them but they are far from made the same,
Things like fin count and rows and row size matter a lot,
PaulDana,
Please send me a link to your unit ( in private ) as not to upset forum cops and suporting venders,
Many thanks!
Cheers,
P.
The13bats@aol.com
Originally Posted by wcsinx
Not saying Dewitts isn't a good piece, but you can get aluminum C3 rads for much less (~1/4th) from other vendors.
NONE are in par with what Dewitts offers...will they cool as good? I do not know I havent tested them but they are far from made the same,
Things like fin count and rows and row size matter a lot,
PaulDana,
Please send me a link to your unit ( in private ) as not to upset forum cops and suporting venders,
Many thanks!
Cheers,
P.
The13bats@aol.com
01-13-2011, 10:06 PM
#27
Drifting
Member Since: Jul 2006
Location: Sault Ste. Marie Ontario
Posts: 1,871
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It sure would be nice to get a cool Dewitt's rad cap! Hint!
Last edited by eastltd; 01-13-2011 at 10:07 PM. Reason: typo
I'll take it!
01-13-2011, 10:45 PM
#30
Race Director
Quote:
Originally Posted by wcsinx
Not saying Dewitts isn't a good piece, but you can get aluminum C3 rads for much less (~1/4th) from other vendors.
I reserched all the Fleabay and net units,
NONE are in par with what Dewitts offers...will they cool as good? I do not know I havent tested them but they are far from made the same,
Things like fin count and rows and row size matter a lot,
PaulDana,
Please send me a link to your unit ( in private ) as not to upset forum cops and suporting venders,
Many thanks!
Cheers,
P.
The13bats@aol.com
Originally Posted by wcsinx
Not saying Dewitts isn't a good piece, but you can get aluminum C3 rads for much less (~1/4th) from other vendors.
I reserched all the Fleabay and net units,
NONE are in par with what Dewitts offers...will they cool as good? I do not know I havent tested them but they are far from made the same,
Things like fin count and rows and row size matter a lot,
PaulDana,
Please send me a link to your unit ( in private ) as not to upset forum cops and suporting venders,
Many thanks!
Cheers,
P.
The13bats@aol.com
either way, im sure you will be happy.... and informed.
08-19-2016, 07:05 AM
#31
Instructor
I am rebuilding my car and saw the sale on radiators. Since I am doing a frame off, I have to watch my money. I've noticed many of you use these and I don't doubt that they are good. I've never had any problems with my 78 over heating even in the Texas summers but it has been about 5-6 years since it ran and then I didn't ever have the a/c charged.
How many of you have changed it just because and how many have had over heating issues with the stock radiator? I'm just trying to decide if I should spend $900 on a new radiator and electric fans when I have so much more to replace at this point. 10% off and free shipping makes it very tempting.
How many of you have changed it just because and how many have had over heating issues with the stock radiator? I'm just trying to decide if I should spend $900 on a new radiator and electric fans when I have so much more to replace at this point. 10% off and free shipping makes it very tempting.
My car runs hot here in Florida, it is an automatic so it is dumping more heat into the radiator than a stick, I am in the process of installing a dual core all aluminim radiator in the car this weekend.
I will let you know how I make out.
It seems more people who post here have Z06's (Non-Automatic)
Good luck :-)
Tony
08-19-2016, 09:56 AM
#32
Le Mans Master
Member Since: Mar 2001
Location: Watkinsville, GA and Glen Cove, NY
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Have a Dewitt/Spal combo on my 69. Best thing I have done. Another benefit with the fans is you can easily fit a spreader bar in there. Best mod for handling I have done.
Bill
Bill
08-19-2016, 12:45 PM
#33
Administrator
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Location: About 1100 miles from where I call home. Blue lives matter.
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My .02 cents,
My car runs hot here in Florida, it is an automatic so it is dumping more heat into the radiator than a stick, I am in the process of installing a dual core all aluminim radiator in the car this weekend.
I will let you know how I make out.
It seems more people who post here have Z06's (Non-Automatic)
Good luck :-)
Tony
My car runs hot here in Florida, it is an automatic so it is dumping more heat into the radiator than a stick, I am in the process of installing a dual core all aluminim radiator in the car this weekend.
I will let you know how I make out.
It seems more people who post here have Z06's (Non-Automatic)
Good luck :-)
Tony
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mrvette (08-20-2016)
