scotth48

I have been waiting to purchase the new single core radiator from DeWitt. Wondering if anyone had this yet and what improvement they have seen over original and also the improvement of using the two core over the original. Did you use a different thermostat or stayed with the stock setting. They also have different fans that flows 30% more airflow than stock, did that seem to help, especially when vehicle is standing in traffic? How easy was the radiator installation and the install for the fans? Do the fans operate like the originals for coming on and off or will the computer need to be reset to come on at a lower temperature. Mine would be going on a 1993 LT1 Ruby.

GREGGPENN

Without having a DeWitt (though having an aftermarket radiator), I can answer most of your questions.

There is no need to reprogram fans, change thermostat, or alter your cooling system from stock -- unless you've modified the engine. People who have frustration with the cooling system don't keep after debris in their radiator "cabinet", understand correct operating temps, consider failing cooling efficiency -- with age, and/or have a faulty thermostat.

Stock fans will keep the engine cool. The stock radiator will too. The stock thermostat is designed to acheive optimal mpg and emissions. Really, even the best motor longevity.

That said, aftermarket radiators can increase the ability to cool an engine in extreme conditions. While those conditions theorectically include temperature/load, it's more likely they'll help by getting you to clean the radiator/condensor...and install a properly working thermostat. Fans pretty much work or don't -- but needs to be verified.

People who install aftermarket radiators, fans, and water pumps typically have also installed modified engines that create more heat. And, yes, DeWitt's products will improve the ability to cool (radiator capacity and cross-section) while also improving the ability to cool at idle -- especially with an aftermarket fan.

People who buy DeWitt's radiators are never disappointed by the ease of installation and performance. However, I have read some complaints about additional/excessive fan noise when converting to one of their hi-speed fans. Whether it's "justified" from a straight-blade versus curved/SPAL type fan is a matter of personal debate.

WW7

I have the Dewitt's 2 row radiator cooling a 383 Stroker motor and I run 180 degrees on the highway with 80 degree air temperture..So yeah, it definitely cools better then stock..I also have the Dewitts high speed fan and it drops the temps down almost twice as fast as the stock fan...I have my fan set to come on at 200 degrees and off at 180 degrees which works out great for my setup....But,,,,I agree with GREGGPENN above.. If your running a stock motor, and keep your radiator and surounding area clean of trash , plus keep your cooling system in tip top shape, you don't need to have a different radiator....Saying that , Im sure the new 1 row Dewitts is an excellent piece, but I don't know if it will cool the engine better then the stock unit....WW

PS,, Yes , the high speed fan is louder then stock...In fact, some people thought I had a supercharger under the hood, but my exhaust is so loud I can hardly hear it....

scotth48

I agree with both of you. My engine is stock and I had cleaned it out in the past, it just scared me some when it would go past 235 and near 240. I like the dewiits because of the all metal endcaps. I may just go with the single row unit and keep my stock fans and thermostats. I am only about 50 miles from the company and will probably just pick it up. I had a overheating problem last year due to a blown hose that resulted in blown head gasket. It got so hot that the plastic tank up on the firewall had expanded and the sensor melted. I realize a larger radiator would not have made any difference for my failure to recheck clamps on hoses, I would just feel more at ease with coolant running a little cooler when stuck in a traffic jam when it gets hot outside.
Thanks for your input and any others that may comment.

cv67

fans are a plus easier to pull the air through a thicker core

I dont care about fan noise I want to see that needle drop when they come on not sit there and fight temps. Put one in my old Z absolute night/day difference. I had the stock rad. witha 160 stat and fans set to come on early it was "just" enough. With the DeWitts sitting in 100 deg traffic is never a worry. Nor a high speed trip across the desert to AZ recently.

Had one made for my 67 should be showing up today

Noone likes paying more for stuff than the 'cheaper" versions but it sure sucks buying the part twice because it didnt work/last/fit as good as the pricier stuff (most the time anyway lol).

PLRX

Last Saturday it was way over 110°F, and Betty Boop's temp was at 190°F on the highway. I drove around the city, and it went up to 205°F.

That's all I got to say.

1993C4LT1

I know these LTx engines are "ok" with running at higher temps. But, you can't go wrong with running cooler. Have to get me a Dewitt when the wallet permits.

desertmike1

I'm liking mine,,

JrRifleCoach

Used to be when running on the hi-way at posted speed then making a pit stop, the temps would sky rocket. And stay high above 210 until back on the road and pushing air through the rad. Now the DeWitts holds temp stable after slowing down and before returning to the open road. Around town with the A/C on at 100 OAT, she holds temps down at 195-198.

The engine is lightly modified and of all the money I've spent, this radiator improvement is the best money spent so far..

miamitaz13

last summer my condenser went.so i replaced that put in a champion 3 row aluminum radiator no plastic parts on it water temp rarely over 200

JoeUser

I installed the Dewitt's single row about a month ago. Fairly straightforward install, but the shroud was a little tight to re-install (due to the foam on top of the radiator and getting the rubber boots aligned for the condensor). I recommend notching the right side mounting tab where you have to clear the A/C condensor line (I actually detached the line's mounting bracket to assist in getting that side of the shroud out from under that &*@?!## hose). Those six little 7mm upper-to-lower shroud screws were fun, too, but not impossible using a small box-end wrench. Needless to say, only one per side were re-installed in reverse fashion (with the self-tapped zip nuts reversed). Now that I think about it, I retract the first part of my second sentence in this paragraph, LOL... it was an afternoon's work, taking my time.

Cooling temps are comparable to the stock radiator, if not a few degrees cooler. Temperature consistency is better, fewer jumps up and down. My temps run on average 100 degrees above ambient (both stopped and rolling, surprisingly). When stopped and idling the temp doesn't skyrocket like it used to with the stock radiator, but that may have been due to air in the system or the smaller cores of the stock unit.

I'm running a 160 t-stat, and haven't reprogrammed the fans (yet). With a 180 t-stat temps would run around 20 degrees higher, all other factors unchanged.

Once I reprogram the fans to come on at a lower temperature with the Hypertech programmer, the 100+ summers we have here in Tejas will be much more enjoyable, knowing that the fans will kick on sooner if necessary. But, it's almost a wash doing the programming, as when the temperatures get that hot the A/C is on anyway, the fans are activated already...

scotth48

[QUOTE=JoeUser;1584329316]I installed the Dewitt's single row about a month ago. Fairly straightforward install, but the shroud was a little tight to re-install (due to the foam on top of the radiator and getting the rubber boots aligned for the condensor). I recommend notching the right side mounting tab where you have to clear the A/C condensor line (I actually detached the line's mounting bracket to assist in getting that side of the shroud out from under that &*@?!## hose). Those six little 7mm upper-to-lower shroud screws were fun, too, but not impossible using a small box-end wrench. Needless to say, only one per side were re-installed in reverse fashion (with the self-tapped zip nuts reversed). Now that I think about it, I retract the first part of my second sentence in this paragraph, LOL... it was an afternoon's work, taking my time.

When I go down to pick mine up, I'll as the guys there about what you were saying on mounting the radiator.

AzMotorhead

Scott48 If youre going down there in person, when the hand you the upper shroud/fan mount bracket, Make sure its bent& drilled properly.
Mine was all wrong. Holes were missing. and the holes that were in there would make the bracket mount opposite of what it needed to be.

GKK

A lot of people don't like the OEM plastic tanks but, my 91 Vette's lasted 21 years and when it finally failed, the Core leaked not the plastic tanks!...

scotth48

I had to reorder today because I wanted it in black which was an option that isn't listed on the web site. I mentioned AZMotorhead's problem and will show them what you said above, maybe a little feedback to them will help make there product better.

Anyone else have any installation problems?

JoeUser

There's not much they can do to help with removing the shroud, that's an issue no matter what radiator you install.

The only suggestion I can make is to perhaps make the foam inserts a little thinner, maybe.

1991Z07

I went with a Ron Davis in mine...bought one with the oil cooler for automatic equipped cars. The OEM water/oil cooler wasn't up to snuff, so I plumbed the radiator in instead.

Track days the oil temps never get above 200, and the water temps never go above 215.

On the street...it runs cool as a cucumber.

For those recommending you stick with the OEM radiator...you realize GM spec'ed those out to BARELY get the job done. Just because it works doesn't mean it can't work better.

An aftermarket multi-core has MUCH more capacity as a thermal heat sink. Add to that an ALL-aluminum construction welded together (instead of bonded) and it is money well spent, especially when you live someplace it gets hotter than the surface of the sun!

I've seen my fair share of C4's on the side of the road with steam boiling from the hood...

AzMotorhead

I suck with paint but here I try to explain my problem
[IMG][/IMG]


I should note that this was on 91 ZR1 and extra holes on the upper shroud spacer are for the AC accumulator

AzMotorhead

This how the lower standoff bracket attaches. Upper standoff should orient the same direction. Unfortunately the way it came it did not.
SO I had to flip the standoff over. Drill all new holes, then trim about 3/8" off the flange at the top.
[IMG][/IMG]

JoeUser

Ah, you're installing the new fan kit, as well. I didn't go that route, and re-used the existing fans.

Can't help you there, but you're right, that's something that could/should be resolved with DeWitts. If there's an issue with fitment I'd definitely contact them (it's possible that you might have been sent an incorrect kit, maybe?). I'm sure they'll make it right, whatever issues you're having...