Why DeWitts?
Burning Brakes
Joined: May 2006
Posts: 1,136
Likes: 8
From: Chichester, UK
but:
What 'Lb' pressure cap do I need? is it 15psi
What size diameter is the upper tube for the upper hose? Is it 1.1/4”
Again 1980, Manual car
Last edited by C3Paul; Jan 1, 2012 at 05:57 PM.
Thread Starter
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
So if your system is working as it should and you run between 180-200 degrees, you don't even need a cap. It's actually pretty silly when people change from a 12# to a 15# or whatever. Why would this matter?
The upper connection on the 77-79 is 1.5" and the 80-82 is 1.25" otherwise the radiators are identical for that group. We use a combination neck that incorporates both sizes.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
As usual Canada seems to be left out. UPS/FedeEx does our routes the same as US.
Burning Brakes
Joined: May 2006
Posts: 1,136
Likes: 8
From: Chichester, UK
The pressure cap rating has very little to do with how your system is going to work. Pressurizing the cooling system only raises the point at which your coolant will boil. A 50/50 mix will boil at about 240f and when you pressurize you gain 3 degrees for every 1 psi. So a 15psi cap will increase the boiling point 45 degrees for a total of 285.
So if your system is working as it should and you run between 180-200 degrees, you don't even need a cap. It's actually pretty silly when people change from a 12# to a 15# or whatever. Why would this matter?
The upper connection on the 77-79 is 1.5" and the 80-82 is 1.25" otherwise the radiators are identical for that group. We use a combination neck that incorporates both sizes.
So if your system is working as it should and you run between 180-200 degrees, you don't even need a cap. It's actually pretty silly when people change from a 12# to a 15# or whatever. Why would this matter?
The upper connection on the 77-79 is 1.5" and the 80-82 is 1.25" otherwise the radiators are identical for that group. We use a combination neck that incorporates both sizes.
Count me in for:
1x 1980 Manual radiator with 1.25" tubes.
Free shipping to friends in UK
Last edited by C3Paul; Jan 2, 2012 at 05:59 AM.
Heel & Toe
Joined: Dec 2011
Posts: 17
Likes: 0
Just bought a 1978 L82 looks to have a new rad but it leaks........do the DeWitts have the name stamped on the radiator or some other marking? Looks to be a 4 core. Droped it off at the shop today. Looks like I know what to go with if they scrap it!
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Racer
Joined: Apr 2010
Posts: 352
Likes: 1
From: Central NJ
Not diameter but tube width, the tubes are flat. Most of the aftermarket aluminum radiators are two rows of 1" wide tubes, often incorrectly called "cores".
First I should say the copper radiators used during the C3 era are huge in size compared to other groups and in most cases a good functioning copper unit will work fine.
When you upgrade to an aluminum radiator it is like adding length to the radiator without changing its size. 30% for the 1" tubes and 35% for the 1.25" tubes. That's a lot when you think of it this way...if your copper core was 30" the aluminum 1" version would cool like 39", while the 1.25" would be like a 41". So, the large tubes do add more but not a lot in comparison to the jump from copper to aluminum. Hope that makes sense?
The cost for the larger tubes is $75 and when the January sale starts that is about the same as the discount. So you could get the fatter tubes for the same regular price.
The sale will start January 16th and run the restof the month. 15% discount and free shipping, which amounts to about $125 savings.
First I should say the copper radiators used during the C3 era are huge in size compared to other groups and in most cases a good functioning copper unit will work fine.
When you upgrade to an aluminum radiator it is like adding length to the radiator without changing its size. 30% for the 1" tubes and 35% for the 1.25" tubes. That's a lot when you think of it this way...if your copper core was 30" the aluminum 1" version would cool like 39", while the 1.25" would be like a 41". So, the large tubes do add more but not a lot in comparison to the jump from copper to aluminum. Hope that makes sense?
The cost for the larger tubes is $75 and when the January sale starts that is about the same as the discount. So you could get the fatter tubes for the same regular price.
The sale will start January 16th and run the restof the month. 15% discount and free shipping, which amounts to about $125 savings.
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Thread Starter
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
Thread Starter
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
Tech Contributor
Joined: Jun 2004
Posts: 20,860
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Don't sweat the paint issue.
Drifting
Joined: May 2011
Posts: 1,536
Likes: 1
From: Boca Raton FL
Instructor
Joined: Mar 2011
Posts: 127
Likes: 2
I've owned a number of racing aluminum radiators. Comparatively speaking, the DeWitts radiator costs less but the workmanship and quality is outstanding. The tanks are tig welded to the core and not epoxied like many racing radiators. Epoxied tanks are not durable and are prone to develop leaks in my experience. I needed a radiator in a pinch for my 70 big block automatic. Called Dewitts and was told they did not have one on the shelf. They had it built and shipped within two days. Absolute dead match. Easily dropped 20 degrees in operating temp. I'll put it to the test this summer here in Phoenix when hit hits 110 plus.
Advanced
Joined: Nov 2011
Posts: 64
Likes: 0
From: Medford OK
Jut a little piece of my dewitts experience and why they truly have the best quality and value product out there.
"Well guys she touched ground and rolled for the first time today and I'll give you a quick rundown...holy s@$! is the only term that seems appropriate ha beautiful loping idle on the bottom end and she just loves to pull!!! Only concerns now are that damn TA bushing that is now very obviously shot to pieces haha. I haven't put a full flogging on her yet but when she hits about 3000 rpm it's time to hold on and say your hail Mary! Incredible power and the center force clutch handles it all very well. A little bity but what clutch wouldn't be concerned the size of the springs in it ha. I cannot say enough about Matt Walsh and all the guys working for the Enginefactory.com crew. This motor looks like a work of art and runs like a bat out of hell! Gotta get that TA fixed tho it's a touch scary to drive with the tail end that loose. Also another shout out to Dewitts radiators. I can't say enough about the quality of their product. On a 90 degree day we idled the car out in the sun with the ac on and the car not moving and the temp never kissed passed 190! Unheard of before the swap and now we are producing a bit more heat with that 10:1 compression ha! Also a great fit when installing and sealing up. The quality of their welds is amazing as is the entire product. Truly a jewel in its own right. Hope to have a video from the passenger seat up soon!"
"Well guys she touched ground and rolled for the first time today and I'll give you a quick rundown...holy s@$! is the only term that seems appropriate ha beautiful loping idle on the bottom end and she just loves to pull!!! Only concerns now are that damn TA bushing that is now very obviously shot to pieces haha. I haven't put a full flogging on her yet but when she hits about 3000 rpm it's time to hold on and say your hail Mary! Incredible power and the center force clutch handles it all very well. A little bity but what clutch wouldn't be concerned the size of the springs in it ha. I cannot say enough about Matt Walsh and all the guys working for the Enginefactory.com crew. This motor looks like a work of art and runs like a bat out of hell! Gotta get that TA fixed tho it's a touch scary to drive with the tail end that loose. Also another shout out to Dewitts radiators. I can't say enough about the quality of their product. On a 90 degree day we idled the car out in the sun with the ac on and the car not moving and the temp never kissed passed 190! Unheard of before the swap and now we are producing a bit more heat with that 10:1 compression ha! Also a great fit when installing and sealing up. The quality of their welds is amazing as is the entire product. Truly a jewel in its own right. Hope to have a video from the passenger seat up soon!"
Thread Starter
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
I guess it depends on exactly where the leak is. If you punch a hole in a tube when installing the radiator you might be able to flame braze the hole with some of the magic rods they sell. However, aluminum flame brazing looks easy when someone else does it but it never works out that way and it is real easy to make it worse. What the article is referring to is tube-to-header leaks after furnace brazing and you can't really get to those with flame brazing. you would have to flow epoxy in there to get to the leak area.