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Too Hot


Well-known member
Nov 23, 2001
San Diego, CA
Black Cherry 1969 Stingray
I know this topic has been covered a couple of times but here it goes again. I have a 427 that ran 210 on the highway and about 240 in stop and go traffic without a thermostat. A couple of people suggested that I get a stat so the radiator could do it's job. I ordered a 160 degree stat and put it in this weekend along with a bottle of red line's water wetter. The temperature gauge now raises to about 240 within the first couple of miles then lowers to about 220-230 and stays there. This is all with an electric fan on all the time. Any other suggestions as to what I can do/check. Today when I parked it, there was steam coming out of the overflow tank.:(


I just talked to the previous owner...news wasn't what I wanted to hear. I thought the radiator was brand new because it looked so good...boy was I wrong. It's the factory correct brass radiator, maybe even the original. He had it out and cleaned/painted and put back in. Darn. Is there any way to tell if this is infact the problem before I make the several hundred dollar dive?

You can usually tell if the core is getting plugged up if you see a buildup around the inside edges of the tubes looking in from the filler cap. Just had a recore on mine, they put in a 4 row core and cost only about 230.00. I also believe getting the radiator cooler external to the radiator will help as well, especially if you run a stall speed converter.

Started checking prices

I looked into prices and found 5 different places and a couple different prices.

Be Cool Radiator: $491.97 (summit Racing)
Griffen Radiator: $200.00 (ball park-Summit Racing)
Speedy Radiator: $154.95
Radiator.com: $490.00
Dewitts: $590

If it costs $230 to have it recored, I think I'd rather get an aftermarket that would be much more efficient. Can anyone give me any words of wisdom as who to go with on this deal?

Thanks again, I'm not sure what I'd do w/o this site.

The recore is more efficient because it is 4 rows rather than the original 3 rows. It also has no problems fitting because it is still the same radiator. Aluminum would probably be more efficient still, I remember a thread a little while back about someone using a Griffin radiator

Took the dive

Well, I get to anxious when it comes to buying stuff for the vette. I went with Dewitts, got the Griffen Radiator and the Spal dual 11" fans setup...2700 CFM! Talk to the guy on the phone and he knocked a $100 off and is going to assemble everything together before shipping it out. Can't wait to put it in. I'll let ya'll know how it turns out.

I got a used one from a 96 Z-28 with fans and all for just $150 and it fits with little or no work
Unfortunately I didn't get that great of a deal...but I won't be dissappointed if it works.
Burbing the system

Any tips/tricks to making sure I don't get air in the system. How would I get it out if there was air in the block? I'm learning more everyday.

Best way to refill it and avoid air pockets is to remove the thermostat housing and thermo and fill the system through that hole in the intake manifold until you see the level of coolant rising to the top of the opening; then install the thermostat (180 recommended) and the housing, connect the hose, and top the system off at the radiator or expansion tank filler opening.

While you're at it, it's a good idea to remove the drain plug on each side of the block just above the pan rail to drain the water jackets around the cylinders - those two plugs are the ONLY drain for those jackets, and an amazing amount of corrosion and crud collects at the bottom, as nobody ever drains them. You have to remove both plugs - the cavities are not cross-connected. When you pull the plug, don't be surprised if nothing comes out - stick a piece of coathanger wire or a scratch awl up into the hole to break through the crud, and coolant will POUR out. When you replace the plugs, put some anti-seize on the threads so they come out easy next time - the first time can be an adventure - use a 6-point socket or box-end wrench.
You are going to love the Dewitt stuff. I have his 2700 CFM spal 11" fans on my car. They move a ton of air.

His radiators are not cheap, so I know you just laid down some major jack on that. The bottom line is, you will be riding cool after this.

I had my fan bracket aluminum welded to the radiator instead of using the screws in the Dewitt package.

Good luck, hope you get it cooled down.

Don't sweat the Z28 stuff, because I really have my doubts that radiator would cool your monster big block on a hot day.
Coolant Choice

I've been reading some of the past threads on coolant choice. Currently, I have the Green Stuff in the car. C4C5 posted that Dexcool doesn't do what it's supposed to do if it's not the only coolant in the system...meaning there is still Green Stuff stuck to the metal after a flush. Here's the thread:
c4c5specialist said:
Hi there,
Well, its really not quite that simple. You see, Dex cool is a formula where you do not have any silicates in the coolant, and it bonds to aluminum and internal parts. Now, the conventional green ethylene glycol bonds differently as well. The reason for this is the chemical composition.
So, even if you flush the coolant out completely, the bonded chemical is still in the metal and other parts of the cooling system.
Remember, even people who attempt a retrofit of the Dexcool to other vehicles, do not really suceed, as the interval will still be 2 yrs 24ooo miles, due to the inability to completely clean the system of the old coolant.
Many people attempt this but the ability of Dexcool to completely work as intended, is the purity of NO other coolant in the system.
Even when asked to do this in a dealer, we cannot perform this, as there is no added benefit.
this is the reasons for my reply.
Besttoall, c4c5:hb

Plus 69MyWay was talking about another problem:
69MyWay said:
I am just repeating what I have heard, and seen.

A good friend of mine is a tech at the local G.M. dealership. They are having problems with Dexcool cars. In fact, my Mother in law has a 97 Fireturd with about 70K miles. Her car started running kind of warm, and my friend happened to be over the house that day when she was visiting. Long story short, we popped open her system and it was crusted full of scale and corrosion. He said they hare having a problem with this and have been having to replace radiators, etc. etc. on fairly new cars that are gunked up. My mother in law took the Bird to the local dealer. They had to pressure flush it several times to get the lumps of crud to start coming out and replaced it with the regular old green looking stuff when they were done.

So, I guess this is going to be like a lot of other things out there, everybody will have some sort of opinion or different experience. I swear though, here cooling system was a nightmare, and I just can't imagine that should get so bad that soon.

What I'm getting at is what coolant should I use...especially considering the Aluminum Heads and NEW Aluminum Radiator.

I personaly will not put "red" coolant in any car that did not come with it. I have seen too many problems with it in GM cars and trucks. I am not sure of the cause but it appears to be temperature related with scaling and resulting plugging of heater and so on especially in S-10 blazers! But I do not know the exact reason as yet.
Has anyone ever heard of Evans? The company is supposed to have a different way of developing their coolant, that reduces temperatures more efficiently than conventional fluids. I hear it's expensive though, at $30 a gallon. I'll see if I can find the article I have on it.

Use ordinary brand-name "green stuff" (ethylene glycol-based anti-freeze like Prestone, Zerex, etc.), mixed 50-50 with distilled water, and change it every two years, and your new radiator will be happy :) . Do NOT convert to Dexcool (for the reasons stated above), and do NOT use the propylene glycol-based "environmentally friendly" coolant (like "Sierra" brand) - its heat transfer efficiency is about 10% less than conventional ethylene glycol anti-freeze at the same concentration, and if your cooling system is already marginal (as most BB Corvettes are), you'll have more problems you don't need. The reason to change it every two years is to maintain the effectiveness of the additive package that prevents corrosion - especially important with non-repairable aluminum radiators.
I have a Griffin radiator in my 75 and that car never has a problem with running warm. I have a 180 stat and that is where I stays all the time. I can run it in traffic with the a/c on and it's fine.
Just make sure your fan shroud is also in place correctly.

I haven't seen it but it is at my sponsor's house (where the vette is). Big box 40"x10.5"x30" and it doesn't weight alot!!!! Can't you tell I'm excited....I think my roommate is tired of listening to me talk about it. :J

Thanks for the confirmation to remain with the same coolant. Here's another question...I've looked and can't find it. What's the coolant capacity? I only want to make one trip to the parts house. I'm gonna go with a 50/50 mix for now.

Fan Shroud: Tom Dewitt said that the fan shroud does not stay on the car with the dual 11" Spal Fans...What do ya'll think?

Updates and PICS of the change on their way in a couple days.


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