It was 103 degrees here in Atlanta today. After doing some research here on the forum I install a 160 T-stat. My engine is heavily modified (L2 in a C5 with ported heads, performance cam, kooks long tubes) and on the highway my temps were a steadily 217 degrees. At stop lights the coolant temps it would climb to 225. The radiator has been cleared of debris and the fluid mixture provides heat dissipation to 265 degrees. By my best estimate is that I will need a bigger radiator. Are there any radiator recommendations? Help!

 

I was running my car very, very hard this past sunday in 98-100* heat. C5 402 heavily modified also, 190-192* oil and coolant with a Ron Davis radiator/oil cooler combo from ECS. All of my track buddies use this combo and rarelt get over 230 on the roadcourses runnig hard almost to redline every gear for 20-30 minutes strqight.

 

Thank you much for the information. What is the cost of a Ron Davis radiator? I don't race but would like my temps to be consistant at 198 plus or minus 5 degrees. Is there something around the $350 to $450 range that will provide the type of cooling that I am after in heavy street traffic?

 

I had similar problems with my LS2 402 in my '02Z. Dropped a DeWitts aluminum radiator in the car and immediately saw a 15 degree drop in coolant temp. Now in stop and go traffic on a hot day, the highest temp I have seen is 201F. On the highway cruising at 60mph I see temps in the 194-196F range.

 

Thanks for the info. What is the going price for a Dewitt these days?

 

Here is the list http://www.dewitts.com/pages/categor...s.asp?catID=19

BTW, ECS is selling DeWitt radiators now

 

I've been using the DeWitts radiator for 3 years now with great success - very effective, great quality and reasonably priced. Also, really good customer service! Mike

 

Running LG Motosports aluminum rad. with oil cooler and temps stay around 190 in 90+ outside temps. Car has Vortech SC with cam and headers.

 

Ron Davis 442 LS7 190 to 220 at the track.

 

Ron Davis or DeWitts.

I do recommend separate oil coolers and not the integrated radiator oil cooler combo.

Oil stays hotter then the coolant. Keeping the two separate, yes it is more work to install, but keeps the temps of both the coolant and oil lower.

Lower t-stats dont help that much. at speed there is plenty of air passing though the radiators. Lower t-state opens up coolant sooner when your at idle IIRC.

 

Which one allows the fan/radiator shroud to be re-installed just like stock without modification? I heard one of these you had to modify/trim the shroud and the other was a direct fit.

Thanks!

 

Looks like the DeWitts is a nice unit and direct fit for the most part.

I have a Twin Turbo 2002 auto and live in Florida, so I need better cooling on the 90+ days (we have a lot of these days). I have tried all the little things to help the cooling system like fans on sooner, cleaning, 160 degree thermo and it is fine just driving around, but if you get the boost going the car temp go up fast. It will cool down but it takes a little while. I am looking to get this Radiator for my car now.

Here is a link showing an install from corvette fever.

http://www.dewitts.com/download/TwiceAsIce.pdf

 

DeWitt's with a Pfadt external oil cooler .

The hot or better yet cool setup.

 

I just got my DeWitts Wednesday. $580 shipped for direct fit, american made, forum sponsor. What more could you ask for.

 

^^Unless you plan to road race your car I don't think you need an oil cooler. You just need a bigger radiator. The 2 big names are Dewitts and Ron Davis. They have about twice the cooling capacity as the stock radiator.

I happened to go with the Dewitts because it is a drop in replacement and lots of people have them and say nothing but good things about them.

 

Procharged C5 here and another vote for DeWhitts direct fit.

 

Hey Guys,

After deciding not to sell the Vette, I am in the preventive maintenance mode commonly known as PMCS (Preventive Maintenance Checks and Services). My car was running hot during our Tour For A Cure trek, often reaching temps of 215° (while cursing) and as high as 240° (in traffic). I added a bottle of Wet Water and for the most part, I think it helped. Upon returning home, I checked the radiator fluid and it showed that there was less than 230° of protection. I added more antifreeze and drove it again. I saw some improvement, however; after 20 minutes of driving the temp quickly reached 235° (panic). I drove home as quickly as possible before the car went into reduce power mode and made it.

The next day, I concluded that the thermostat was bad and had frozen shut so; I drained the radiator and replace it with a new 180° thermostat. Oh and yes… I took the radiator/condenser cowling off, looked down between the radiator and A/C condenser and found all kinds of crap on the radiator screen. (What you see looking under the car is the A/C condenser. The radiator is behind it and not easily seen.) I cleaned the radiator and condenser with a vacuum cleaner and water hose. After I was done, it was clean enough to eat off of. Problem solved! I drove the car the next day and the temp was a little better but after a while the temp creped up to 230°. This was a little better but for a long drive it would be risky (BTW… on all of the days I test drove the car, the ambient temperatures were between 93° and 103°). Well… that really sucked so I went to Summit Racing and purchased a 160° thermostat. I installed it and was so happy because I knew that this would make all the difference. Everyone said, "Install the 160° thermostat and adjust the fans". I assumed that my previously adjusted fan settings were still in place since the fans were coming on strong at 192° as opposed to 215°. Well… I installed the 160° thermostat and let the car idle for 20 minutes and the engine temp never got above 192°...success! I took the car for a drive (about 30 minutes) and the car temp was great. Little did I know that the car was getting just as hot as before but at a much slower rate...CRAP! The top temp for that little excursion was 225°…Great... another 5°...oh happy days! I brought the car home and let it idle for a good 15 minutes and the engine cooled down to 188° before I turned it off. Crap, what does that mean??? The radiator is clean, the coolant fluid is good, the fans are working above standard and the car is cooling well at idle... What the hell?

So, off to the Corvette Forum I went. I should have been looking for a job but when I get fixated on a problem, I can't let it go. For two days I researched and asked questions on the forum. I found many other threads on similar subjects. The only relevant facts I had were (1) the engine was running hot with the A/C on as high as 235°, (2) the engine is a heavily modified LS2 (retrofitted) and (3) the ambient road temps were between 93° and 103°. I asked the question on the forum using these facts and while digging around found out that others have been experiencing the same problems. There was one post out there that asked something like "what is your engine temp". I zeroed in on that post and many stated they were running between 200° to 225° and some considered that normal. One thing I did find out was that GM designed the LS engine to run that hot for fuel efficiency and for emissions. Not for me! GM won't be with me when my engine is blown from a cracked head or blown head gasket. I don't care what it is designed for, not my engine! There were folks running 225° temp all day-every day and didn't think twice about it even after reading the post...LOL. One guy had a temp of 255° before he realized something was wrong! Double Dumb with 2 snaps..." Hated it"…Smile!

Okay, I started another post and added my question and relevant facts (modified LS2 with 160° thermostat and clean radiator). Well, what do you know… the stock radiator is too damn small to provide ample cooling for a modified engine. When you see it, you will realize what a piece of crap the radiator is! I started looking at the forum members that posted the specs of their mods and almost all of them (at least the ones with modified engines) added a new radiator package. Okay… double crap… more money!!!!!!!! The stock radiator has 1-core and is about 1.25 inches thick, if that. Not much cooling in terms of liquid heat dissipation. It's the fans where GM derives the synergies for cooling. Electric fans are not parasitic to engine operation. They spin faster and spin when the car is not moving. Because of these properties GM can get away with having a smaller radiator (as compared to the radiators in the old muscle cars) and achieve the desired cooling. Vettes with modified engines (430 RWHP plus) produce more heat than the stock engines with 1-core radiator can handle, especially while driving. Hence the reason my engine was cooling efficiently at idle with the 160° thermostat and running hot while driving.

According to the Corvette Forum, I needed to install an after market radiator. The one that came highly recommended is one made by Dewitt. It is a direct fit and fits in the same space where the stock radiator sits. It smartly fills the one-inch gap between the stock radiator and the A/C condenser plus it uses the stock fans (although they offer after market fans). In fact, the stock fans fit better on the Dewitt radiator than they do with the stock configuration. Hell… the whole damn configuration is better plus it is a 2-core radiator (twice as thick) not a 1-core as with the stock radiator. The guys on the forum that used this radiator were seeing engine temps no higher than 198° ON THE TRACK and 192° in 30 minute "stop-an-go" traffic with ambient temps of 100° plus. Most were using the stock 180° thermostat. With that said, I may have an over cooling problem in the fall and winter.

Okay, I was convinced. I ordered my Dewitt radiator yesterday and it arrived on Friday. I studied the installation instruction 5 times before starting the process. The install seemed very simple.

I've attached pics of the stock radiator, dirt and the radiator drain plug.

Picture 1 - the dirt I vacuumed out of the radiator fins.
Picture 2 - shows the cheap radiator plug (petcock) that can break on the first use (no problem auto zone has plenty). To open turn CCW with a 1/4 wrench (quarter turn) then pull out. Evidently mine has never been used even though the car has been to the dealer for a radiator flush.
Picture 3 - shows the drain where the radiator fluid exits the radiator
Picture 4, 5 - is the dirty as hell radiator fins. Prior to this, I assume the radiator was the A/C condenser.

Well I finally finished. The radiator arrived at 2:00 pm on Friday as I requested. By coincidence the UPS deliveryman was a former Corvette owner (C2) and he knew what was in the package before he saw my car. There are a few things of note before talking about the installation:
(1) Eat your Wheaties before starting because you are going to need the energy.
(2) This is by far a two-man operation. Lifting and aligning the radiator, fan assembly, bench pressing the radiator out of the car and the constant ups and downs. I thought having an auto lift would make things better…well afterwards I did not think so.
(3) The original estimate to do this job was 2 hours. Well try about 6 hours for me. I am slow and methodical (measure 3 times and cut once).

The process started with elevating the car off the ground at least the front higher than the rear. This helps to drain the radiator while allowing the remaining coolant to stay in the engine (this is most desirable to help with the burping process, which is the last step to compete the install process).

Next, drain the radiator, remove the air intake (filter, bridge, etc) and disconnect the upper and lower radiator hoses along with the heater and overflow hoses (4 hoses). This was easy. Okay the next step is removing the fan assembly. This was the hardest part of the entire job. This was where the CURSING started. Being a military retiree my lexicon of curse words are rivaled by very few but during this process I ran out of curse words which forced my to create some new words. Taking out the fan took an hour. The directions call for the use of needle nose pliers; never used them. Two flat head screw drivers; one large and one small were adequate. The fan removal started with disconnecting three hardness plugs and then the harness guides…a long process and hard as hell. This was a tight fit. Now to pull out the fan assembly; there were more curse word. The assembly had to be lifted out of its lots (found on the radiator) and then let fall on the sway bar. Afterwards, I crawled from under the car and grabbed the fan assembly from the above and pull it out at a 90° angle (passenger side fan first). After the fan assembly was removal, I removed the radiator, bench-pressing it from underneath the car, lean it on the sway bar and pulled it out from the top.

Good the radiator was removed. I immediately saw that it was filthy, filthy dirty. The radiator was not only dirty but the dirt was impacted within the fins. I held it up to the light and could not see though it much. I let it drop from a low height to the ground and noticed the amount of dirt that fell out. Nasty!!! Spraying water through the condenser and through the fans never helped.

The process of installing the Dewitt radiator was a simple and straightforward process. With the exception of cutting a small notch into the radiator plastic frame assembly (as stated in the directions) it was a problem free process. I reassembled everything (radiator hoses, intake cowling, fluids, and burping the radiator). Oh, placing the radiator on the clips on the condenser and the fan assembly to the clips on the radiator was not a fun process either; definitely a two man job.

Now for the start and test-drive. It was 95° outside and the car, in stop and go traffic, never got above 199°. That’s super when compared to 235° with the stock radiator. On a cruise my temps were 180° while every else’s were 199° (sometimes 205°). In fact while driving in convoy, I surveyed one car and they reported a temp of 201° and as I started to report my temp as 180° it dropped to 178°. Praises to Dewitt!!! I am now satisfied that my cooling problems have been resolved.

 

Glad to see that you were able to resolve your problem to your satisfaction.

BTW, Nice write-up

 

ABSOLUTELY A GREAT WRITE-UP!!!!!!!!!!!!!

I was and am having overheating problems and you gave me the exact directions I need to follow until it is solved. I'm glad you got yours fixed. I am sure with these pain taken directions you wrote, I will be on the road to recovery also. Thanks again for all your hard work and sharing it with all of us.

 

Hey Guys,
This was my first detailed write-up. I just had to share my experience in hopes that someone would at least read it. Many of us are "hopping-up" our engines with no consideration for engine cooling. I was glad that I was able to help someone for a change. Good Luck!