I looked over a DeWitts radiator at the Bloomington Gold show last week. They had a nice display set up and were very helpful. Their product for my 91 had 2 rows of tubes instead of 1 and had aluminum side tanks instead of plastic. It looked to be well constructed.
I just cleaned my original radiator and got rid of any crap that was between it and the AC condensor. Not ready to replace it yet but when I do I will consider a DeWitt.

 

I drive my vette A LOT and more than half of it is in slow moving cloged freeway traffic. I used to see digital temps of 230 all the time. About 15K ago the plastic sides of the original rad developed a few hairline cracks and I replaced it with a new stock rad and it's never gone above 190.

I looked at the Dewitts at the time and it is a high quality unit. If you can afford it I bet you'll be very happy with it but my personal view is that unless you're racing (or live in Fla) you don't need it. A new stock rad will make a world of difference.

 

^^Anther un-Solicited testimonial speaking out for basically having a clean radiator in the car vs a half clogged sediment filled POS.....

So, Peabody puts a new radiator in his car and even though it is stock.......it seems to cool the cars engine quite adequately

 

Okay......so, the next issue after the radiator is the thermostat......I am also replacing thermostat and assume GM replacement. If I decide to go with an oversize radiator......then does that impact the replacement thermostat? Probably not but I see comments about a 160 deg tstat......

 

I would split the difference and get a 180 instead of the 160. The stock radiator would never let your temperture get below 180 anyway in the warm weather and a 180 will still allow your heater to put out heat in the winter..WW

 

1) In my opinion 180 degrees. Opinions will vary.
2) Best is subjective. You ask 10 people, you will get 10 different answers.
3) An oem quality replacement radiator, waterpump, thermostat etc has served me well for 19 years that I have owned my 87.

Although I live in the north, we get days that the temp is 100 plus derees, with 99% humidity.
In spite of that, my oem stuff kept the car perfectly cool, in spite of the fact it has more miles on it than I care to disclose on a public forum.

Keep the stock stuff maintained, and it is plenty good.

I did recently upgrade to a Dewitt's because I will throw big cubes and big power under the hood in the future. Becuse my oem plastic tanks were developing small surface cracks, I made the decision to upgrade. If the 383 was the engine that would stay in the car for life, I would have used an oem replacement.

 

Don't start!!!

Ok....do me a favor...tell me now that all that I've posted (in your mind) is bunk.....I'll leave your thread if you think I am full of BS....

I mean, I post all sorts of info about the stock system being perfectly adequate and you returned with more "hoopty" solutions.....I don't always know when I've worn out my welcome...

 

Not 100% correct.......Mine will get too cool on the highway even on warm days....I had to put a stock T-stat back in (previous owner had a lower temp one) due to mine getting too cold and the Overdrive kicking out at highway speeds.

Refer back to my pics......on the highway...mine drops to 179° every time.....I assume that is where the T-Stat gets somewhat closed, and 179° on the low side is perfectly fine with me.....but with the old T-stat (maybe defective after years) would allow that coolant to get below 160° three minutes after getting on the freeway. The OD would kick out..and the temps would rise due to the RPMS increasing and then the OD would kick back in and the cycle would start all over again.....

 

Since you phased the question as "Good Investment", I'd say YES they are. That's because you will NEVER blow out a end gasket or crack the plastic end tank because that cause has been eliminated. If you maintain the system coolant and change it on regular scheduled times, you may never need another radiator ever. So, yeah I think they are a good investment.

Is a bigger radiator necessary? NO, and thats why you will get multiple opinions on this subject. The stock radiator is "adequate" but marginal. If the radiator is clean, you haven't modified anything, and you don't drive in the desert you will be fine with the stock single row. When you start to build up crap either inside our outside the core it reduces the cooling efficiency and temps start to rise because the single row core does not have any "spare" capacity.

The double row core is a 100% increase in capacity. Many people will install one and say they threw away $450 because it made no difference at all and that's because they are not taxing the cooling system for the extra to show up. You only benefit from the robust design when you tax the system, such as racing hard and/or driving above 100 f temperatures, the radiator isn't perfectly clean, or you get stuck on the xway in the hot summer. For some it just piece of mind to have the extra capacity should you ever need it.

Then you have people that cannot accept the fact GM designed these cars to run hotter than their predecessors. Fans are not designed to kick on until 228 and 190 stats are normal. You can install a 160 stat but unless you live in a 70 degree climate all summer you probably won't get there. There is nothing wrong with running 220-230 with C4's but if you are in this group that don't feel comfortable with that, you will probably need a bigger radiator to get it lower. Some with say they did it with a 160 stat and kicking the fans on earlier but leave out the fact the are living in the north. The ambient air is basically your cooling power, kind of like freon is for an AC unit and the wide range of air temperatures explains the wide range of results you see posted.

First design C4 (84-89)



Second design C4 (90-96)

 

There's really no point in replacing the thermostat with a cooler one unless you also change the set points for the fans. The thermostat will only affect the minimum temperature. Oversized radiators will increase cooling capacity and allow the engine to operate within a tighter range of temperatures. With a Dewitts radiator, 180 stat and fan set points that correspond to a 180 stat, you can easily keep operating temperatures between 180 and 200 even in stop and go traffic. That's the setup I run and those are the temperatures I run in the CA desert with the A/C on.

One drawback of low temperature stats is that oil temperature will also drop if you have an oil cooler. You need to get oil temp over 212 occasionally to remove moisture in the oil caused by condensation.

 

Well said Tom. I'm one of those that appreciates the peace of mind knowing I can drive in any condition and cooling will not be a problem. Your products are outstanding!

 

IMHO
The factory radiator is just fine when ambient temps stay in the 80's and below.
But let the thermometer go above 90 and run with the A?C on, we're talking apples and oranges.
My 86 had a new OEM style rad and summer running was always a high temp adventure.
Once the cam and good tune was included I would see avg's of 210-235.
My larger rad was the magic that allows the engine to run at "normal" temps.

When some one is having temp probs, I recommend they check for debris, fan operation and replace the cap and factory spec t-stat first.
If they still can't control temps then consider a larger radiator.

 

What is the Rated Horsepower Cooling Capacity of Your First design C4 (84-89) Aluminum 2-Row Radiator ?

I Checked out your website for more details.

Then I looked at Be-Cools radiators website.

I am more interested in Your Dewitt C4 Aluminum Radiator Now for my 87 Vette.

I have used a Be Cool Radiator in the past for another car of mine, not a Corvette, and there was some modifications that had to be made for installation. Did a good job of cooling when done.

Be Cool lists 2 radiators fore a C4 (1984-1989) in 350HP and 400HP ratings.

How are they Coming up with these ratings ? What is the maximum BTU Rating of Your C4 Radiator ?

Thanks, BR

 

I'm glad you asked your question in BTU format, as we are the only ones that actually do it that way. You can't really use HP as a rating method because it really depends on how that HP is used and other factors such as tuning and ambient air temperatures.

Rating a radiator based on the heat rejection rate is the only REAL way to talk about capability. We know what the radiator will do but we do not know what your engine does. It's exactly the same way they sell barbeque grills, they list the BTU power rating. Asking how many HP you can cool is like asking how many hot dogs you can cook.

What we do is list the original factory btu and the rating of our radiator to indicate the amount of cooling capacity you will have when upgrading. All these numbers are in our catalog, which you can download from the website. But for your model A84A, the stock single row is 3545/btu/min and the new double row is 5051/btu/min or a 30% increase.

 

That is Quite an Increase over the Factory BTU rating of a C4 Radiator. Using Your A84A 2-row Aluminum Radiator.
I will Buy Your DeWitt Radiator when I am Ready to do so.

Any Idea what the Callaway TT 1987-1991 Corvettes used for a BTU radiator rating or what application that radiator was originally used from ?
Callaway removed the stock L-98 radiator and installed a Brass and copper radiator.

 

Also If Im not mistaken the Dewitts is the only true (Drop In) C4 Corvette radiator..All the others do need to be modified in some way..Took me about an hour to install mine, and about 35 minites to install the high speed Dewitts fan, which is another great product......WW

 

Where to begin.....your statements do not support my facts or results....

The only one that agrees with my test data is the first statement....yes....if debris inside or out builds up....then the radiator does not work.....you made my original point.

As far as driving in the Desert, I live in SoCal and drive through death valley numerous times per year to work in Phoenix or Las Vegas......I'm not seeing what you describe.

I can't accept the fact that the cars are supposed to run hotter when I have to take steps to keep it from dropping below 160°F and never see over 220°F

Lastly, SoCal, Las Vegas nor Phoenix are located "in the North"

 

Might be an interesting place to add this about cooling fans.

When I’m evaluating how well a cooling systems works at idle & low speeds, I hold a simple hand held “Wind Meter” in the grill opening of the car (not to close to the radiator), like this one



In most late model cars & trucks (1995+) I’ve tested, the fans are capable of generating the equivalent of about a 10 MPH wind in the grill opening.

My C4 (a low mileage 1988) would only pull about 6 MPH with and without the auxiliary fan running (made no difference?)
This is with all the leaves and debris cleaned out and the radiator fins blown out with compressed air (stock radiator)

I removed both stock fans and installed the DeWitt’s replacement fan (below), and the wind speed picked up to a little over 9 MPH.
It doesn’t sound like much, but it stopped that slow 200 – 210 – 220 – 230 degree creep I was getting in stop and go traffic.
The only downside is that it’s a little on the loud side, compared to the stock fans.



If your cooling problems are mostly low speed, it might be a cheaper option to try, before a full radiator upgrade.

 

I don't doubt everthing you said is happening to your car, or another one 3000 miles away. What I am basing my input on is thousands of cars we have helped, even when cleaning or a new radiator didn't do the job. I'm glad your system is working so well but believe me, that is not the norm.

I have to be very careful with the words I use, as was the case when I said NORTH, SOUTH, AND DESERT. To be more specific on hot climates I should say 110-120 degree ambient air.

 

I live in CA as well. Your facts don't support my facts. So who is right? It doesn't matter. The facts are that Tom manufactures a great product that delivers results. He has been pretty neutral in his input. It sounds like you have an axe to grind. I have no idea why.