K.C.E.

I have a '94 LT1 with 72,000 miles on it.

I am replacing the water pump, thermostat, all hoses, etc. I was going to take the radiator to a shop and have them clean if for me. It cost $120. A new one costs $185. So it makes sense to just buy a new one and not worry about it.

When I was looking on-line for radiators I notice that some places (i.e. Corvette Central) sell larger radiators for better cooling and they are all aluminum (i.e. no plastic sides). The cost is about $500.00. I use my car as a daily driver which puts me in heavy rush hour traffic in the Washington D.C. area. In my opinion that is that most difficult on a cooling system. I do not do any racing. Any recommendations or experience with using the larger radiator? Is it worth the investment? Is the install difficult? Seems to be plenty of room; however it will make the air space between the a/c radiator and engine radiator much smaller.....will that effect the ability of the a/c to work?

jhammons01

Once you get a clean radiator in there....you'll see that that stock system.....properly maintained....will cool adequately

This BS about C4s being "designed to run hotter for emissions" is just BS....a perpetuated myth

turbodiesel

they run up to 230 bcuz thats when the fan relay kicks in ...

WW7

Until I put a 383 in my car the stock radiator did a fine job, and it would have probably done ok with the 383, but I had the money and wanted to get the Dewitts radiator for an upgrade along with a higher cfm fan ,and a 180 degree stat..Also the guy doing my tune lowered the on and off points for my fan.If you keep the area in front of your radiator clean, and maintain you coolant and system, the stock radiator does a fine job....WW

Aurora40

The GM one should be more than adequate for stop and go traffic if everything is in good working order. All-aluminum ones won't have issues with the end tanks cracking, and that sort of thing. But it sounds like after 16 years, your plastic one is still trucking. The stocker was good enough for LT4's and LT5's making more power and heat.

Why are you replacing it?

You could probably remove it, clean the fins carefully with a pressure washer or something, and save $120-185? I'm also in Leesburg, FYI.

GREGGPENN

Kinda. Engines do run hotter than earliest SBC 350's. They did purposely raise the running temp range in an attempt to get a cleaner burn. (Then, NOx becomes an issue.)

CFI-EFI (and others) have pointed out that a hotter engine is a more efficient one [heat = power]. Consider that fuel is leaned as a motor gets hotter. It doesn't need as much fuel because it's running more efficiently.

I understand your point though. Corvettes are no different with regard to temperature range than other SBC 350's of the same vintage.

GREGGPENN

Check other places too. If it's like my L98, you can find all-aluminum radiators near the price you saw for HD models. There have been a couple of threads on that in the past month/two.

FWIW, my local radiator shop stopped "boiling out" radiators because of the plastic ends. Said it was too risky and better just to buy a new one -- IF NECESSARY.

surfer93

WHAT????

Reverse cooling is designed to let the engine run hotter and keep heads cooler to eliminate knock, also the stat is 190, read any literature you want, the lt1 is meant to run hotter than most, that is why the fans kick on at such a high temp.

To OP, you can take the radiator out yourself, it is easy to do and not hard to get to. You will not believe all the stuff you will find in there. I lived in the DC area and now in FL, mine would get real hot until I cleaned out the radiator and changed the clamps, also did the throttlebody bypass, did not have any more temp problems.

VenkmanP

NOS GM radiator $99. No-brainer.

http://www.corvetterecycling.com/199...p/52473260.htm

runner140*

Boy do I agree with that. After 30 minutes of driving in the hot South Florida sun, I run from 175 (highway) to 205 (traffic) and gets up to 215 in very heavy traffic. Stock radiator and a 160 t-stat. Thats with over 180,000 miles.
The above temps have been consistant for over six years.

K.C.E.

Appreciate the input.

Before starting this adventure, my digital temp reading would hit 230 regularly on the way home from work.....and my analog would get real close to the 260 mark....this always made me nervous....and probably the main reason I am replacing the radiator as long as I am in there replacing water pump, opti, etc. In addition, I assume by removing the radiator and cooling fans, that I will also have a lot more room to work on the opti and water pump.....and I want to inspect the front main seal while I am in there.

So back to the radiator replacement. I just do not like my analog getting close to 255 to260 deg and am not convinced it should get that high on a regular basis. A difference of 25 deg between the two temperature probes seems a little high for my comfort. I also do not know if there was anything wrong with my cooling system components before my water pump began to fail.....so is the analog at 250 or 260 appropriate? My current approach is to replace the radiator with the stock unit at a minimum since it is relatively inexpensive and significantly too costly if the old one does have something clogged in it......maybe 'preventive maintenance' is what I am doing.

What I am hearing from the responses is that everyone seems to agree that the stock radiator is a good decision.

Throttle body bypass? Are you saying that you rerouted hoses to by pass the throttle body? What is the advantage of doing that? I did note that the hose on the driver side going into the throttle body area is going to be a real challenge to remove.....not sure how to get a tool into the small location. Advice welcome on that!

Flame Red

All I can say is that I installed a DeWitts radiator years ago and it never runs anywhere near as hot as it used to with the stocker here in traffic in the Inferno of Florida. No, my stock rad was not plugged with road crap. To me it is worth its weight in gold.

jhammons01

Listen, The ones that come up with crazy solutions for cooling down a system...and continue to rely on their fan kicking on to hold 240° temps......they are just in denial....after questioning most...they admit that they never pulled the radiator out......yet still can't figure out why the temps are so high...so they start adding gadgets and snake oils.....

No...your temps bumping 260° is no where near normal or acceptable.

Your Water pump failing is a blessing in disguise. You need to take the whole system out and clean it.......

Here I am cruising along after I addressed my cooling system, this pic is on the highway on a June summer day



Just to be thorough, I started on City streets with this higher temp reading....



So.....it is nice a warm and then I get on the highway and the temps drop so low that the T-stat has to close......read the whole thing here

http://www.corvette-guru.com/modules...d=8924&forum=1

Not to mention, look at Runner140*, he got the same results....and he is 3000 miles away....how could we both perform the same repairs and see the same results unless what we were saying is true?

~$60 Water pump, new hoses, New T-stat, ~$100 OEM radiator, deionized water with a 50/50 mix of coolant.....

I never see those temps again.......and yes...there was a day where I was sitting in stop and go traffic on the 101 Hwy......oh, the temps were also 101.....and yes....I hit 260°....so I pulled over and let it cool down. Scared the crap out me.....

I also saw these high temps....and once I started addressing the problem "properly" the issue seemed to go away for good.....and I have nothing but stock parts......

The proof is in the pudding.....so folks can chatter all they want about this design or that design.....all I know is....once I fixed my system....I had to go back to stock temps T-stat or else my car would get too cool......and the Overdrive would kick out.

How many folks on this forum start a thread talking about their car running too cool???

WW7

You can't argue with success, I agree with what (jhammons01) is saying....WW

PS; And he even has pictures...

kimmer

But it's not a lt-1. I believe the digital is the head temp and the analog is block, that's why you have 2 of them. The head temp will be cooler because of the reverse flow. It's normal in city driving for a lt-1 to get up to 228-230, fans kick in at 228-229. Highway temps should be around 192-198.

jhammons01

^^you know that?? or is that what you "see" driving your car.....

JrRifleCoach

DeWitts is the best.

YES!

NO!

NO!

One of GM's biggest failing in the C4 was the undersized radiators.

pcolt94

- I can only add to all of this is that a bigger radiator is better.
- I do feel also the radiator in the vette is undersize.
- Performance is poor in traffic in hot climates.
- A radiator of 15+ years will never clean up as well and give the performance of a new radiator. (A portion of the time the cooling fins (veins) develop pin holes after the cleaning and solvents used).

I did install a GM radiator but the new part was almost a ½ inch thicker which made a nice difference. I almost wish I had put a oversize radiator in at that time if I had known to difference it would have made. However I can make it with the new radiator I have now as long as I can control the secondary fan which I do.

RICEKILA

I removed the plastic tanked wanna be radiator when it started leaking like a sieve

I installed a real metal one with a 2" core - cross flow - from Performance Specialities - if I remember correctly

With the 160 deg. stat. and the 180 deg. fan switch --- its never gone over 210 deg's.

1985 Corvette

So what is the best thermostat to use in the stock application? Best radiator? I see Corvette Central's for $200 area for a stock repro. My old rad, like the rest of the car was in terrible shape. Now that it's all going back together, I just needed a good reliable cooling radiator and thermostat.