Qblue92

I think my '60 is running hot. the longer I drive it, the hotter it gets. I drove it to a show tonite, at 4pm in about 92 degree heat. it got hotter as I drove the 25 min trip and gradually got to 215. On the way back, in low 70's temp, it got to about 185 and then heated up to 200 at a light close to my house. it just gets hotter. it doesn't cool off. going 65 on the freeway, it gets gradually warmer in hot air or stays constant in cooler air. it gets hot sitting still.
I have installed a new water pump, 180 thermostat, the radiator was recently redone by the prev owner, tried flushing the system, checked the timing(12degrees), sealed off the gaps around the radiator so all air would be directed thru the rad, installed a bigger flex fan, i did a compression check on the cylinders ..they're ok.
what's next? is my carb off? vacuum issues? try another thermostat? no thermostat? is my engine krap? the car runs really great other than this. it doesn't show signs of overheating, but i'd love to know why the temp gauge only goes up. I don't think the gauge is off. it was compared to a laser temp zapper and seemed fairly accurate.
My birthday is soon, all I want is for this thing to run cooler. pleeezzzz share your wisdom.

ctjackster

I chased an overheat issue myself after I got my 65 last year. And we are not alone. Here are the common questions.

First, is it really running hot? In other words, is it boiling over or jus tthe gauge freakin you out - if just the gauge and no other signes of a constant overheat condition, your gauge may be wrong - mine is, reads about 10 15 degrees hot depending on what the temp is.

Second, your "prev owner redid the rad" comment is sure to get focus - redid it how? Is there a correct "repro as original" rad in there now (read that to mean a Dewitts) or something unknown? Even if it is original, chances are THAT is way past 100% effective any longer.

Third - flex fans? how about putting the stock fan, or a solid but higher # of fins fan on. Also, how IS that fan clutch? You can put a fan clutch eliminator on just to check out the difference.

Fourth, T-stats, unless stuck closed - only help an engine perofrm better beofre hitting operating temp - they - or a different heat range t-stat - will do nothing to avaid an overheat situation.

We'll get you back to driving without eyeing the temp gauge, just have to work through the issue methodically.

John McGraw

Replace the radiator.


Regards, John McGraw

62fuelie

DeWitts has a direct fit aluminum replacement that should go a long way toward solving your problem. Also make sure the rest of the cooling system is clean inside, ie the block water passages.

Dave62

Well many of us have heat problems!
Is the motor stock?
Do you have the pan under the front that direct air at speed to the radiator?
This will help the at speed temp.
If you have the pan and are heating up at speed...then its not the fan....fan is for stop or low speed. You are not transfering enough heat through the radiator...Tom's thats DeWitts will solve this problem...but you will pay $$.
After that if there is still an issue in traffic then its fan time...either electric or better fixed fan.
If the vette is not stock...make that NCRS show...then I would buy Tom's system that has the electric fan already on the radiator.

All of this assumes that the timing is correct...no head gasket problems...hoses do not pull together when hot...temp is really a problem....water pump and thermostat are in good condition.

Boiling over in traffic....and always having to watch temps is a pain in the rear!

Dave 62

Ironcross

Qblue92

I looked at the radiator angle vs. the hood angle. would i have to remove the hood, or just undo the hood prop and lean the hood forward a bit??
Is a dewitt the best thing for it? does BeCool make anything good for it??? does painting an aluminum rad. hurt its ability to cool??

Dave62

DeWitts....aluminum origional is the best...best BTU transfer...but also the most exspensive. It is painted for the 62 I do not know about 60..
If painted from the factory then DeWitts is painted..
You do need to remove the hood....easy job with two people...
Just be sure to pencil mark the location of the attach points to help with alignment when reassembling.
Dave 62

John McGraw

You could probably get the radiator out, but I would pull the hood just to make it easier. I think that Dewitt makes the absolute best radiator for a direct fit application. I bought a Be Cool radiator for the hybrid that I am building now, and I had to work on the mounting a little to make it fit correctly. My current car had to have some custom configuration of the inlet and outlet to work with my LS1 engine, otherwise I would have used one of Tom's radiators.

Regards, John McGraw

mrg

Sounds like the radiator in your car has no margin for any extra heat rejection. I had the same problem you describe. It got to the point where I just about had one eye on the road and the other on the temp gauge . .! .. The problem was solved when a brand new Harrison aluminum radiator took the place of the old original. With the new install it didn't matter how long the car sat idling or how high the outside temp was when driving at speed - engine ran cool at all times.

John

norvalwilhelm

I know this arguement goes back and forth but I did alot of testing trying to come up with the best combination for my blown big block. I have temperature censors in both heads and also monitor difference in heads temp after heat soaking and I found from removing every second time the thermostat and monitory temperature. I could get away with either of my manually controlled electric fans on the expressways with the thermostat and with I need at least one on all the time. I like to run about 190 and had a 165 thermostat and a 185 for testing and really after spending weeks taking it out , in the next day and getting a feel for what happens,
I run without, almost never use the fans on the expressways. I also run the water pump 30 % over engine speed.
Another strange one is the motor runs slightly hotter with the lights up at night even though the air is cooler.
Try without the thermostat to see if it runs a little cooler.

magicv8

Try wraping a long thin strip of aluminum tape (for ductwork) around the wire to the sender. The heat of the intake manifold exhaust cross over can melt the wire or just alter the reading. Use an infra red gun gauge to check whether the gauge/sender is correct.

65nassau

No matter what you do, if you wind up painting anything, you need special paint for heat transfer surfaces. Regular paint builds up too much and you will kill the heat transfer.

Not sure where to get them, but radiator people Dewitts etc, can help you. Stay OUT of the paint aisle at home depot!

SWCDuke

OE engine? OE radiator? Or is everything modified? What is the age of the radiator since new or the last overhaul? What is the entire ignition map? Is the vacuum can properly matched to the engine's manifold vacuum characteristics. Does it have full time vacuum advance?

Your problem could be anything, but without some details on the configuration and history people can only guess, which is not of mluch value.

Duke

Hitch

65 Nassau as for the paint when I got mine Tom said that Krylon or Rustolem is fine for this application as have others in previous posts...

Coves4me

qblue92,

I have a 59 that I purchased a DeWitt's radiator for, and it fit perfectly. You do not have to remove the hood to bring it out the top of the engine compartment. Just go slow so you don't lose your balance from the awkward position of raising the radiator.

You mention a "flex fan". I'm assuming that the original fan for the car is not installed. If that's so, this could be your problem. My 59 has a 4-blade steel fan that is attached directly to the face of the water pump pulley. This is correct for a 59. But, in 1960, the fan had a 2 to 2-1/2 inch deep aluminum spacer between the fan and pulley to put the fan farther into the shroud and improve cooling. I hope it is not one of those old 1960's type "Flex-a-lite" fans as they are totally worthless. Their blades are too small and they don't move enough air.

I would first improve my cooling by putting in an aluminum radiator from DeWitt's and then a factory 4 or 5-blade fan that is about half-way into the fan shroud with the use of a spacer. Make sure that your water anti-freeze ratio is 50/50 and keep the 180-degree thermostat. Although not stock, I would also use a Dayco Poly-Cog fanbelt as they tend to wrap better around the pulleys to avoid any slippage. Good Luck.

GCD1962

Running hot always seems to be a "hot" topic (sorry for the pun). I don't know each individual circumstance, but thought I would add my set up that has my 62 never overheating.

The engine is a 70 LT-1 short block (bought brand new from Chev in 1972). It was installed 32 years ago and now has about 30m miles on it without any problems. The heads are Dart II heads installed about 12 years ago (I used the chev steel gaskets). It has a torker manifold with 750 holley #3310. The distributor is a dead stock 62, 340hp mechanical still using the two sets of points. Total advance is approx 38 degrees. It has headers and the water pump is a stock gm unit for a 62 (never changed since installed 32 years ago). The temp sending unit is the original one that came with the car (I put the original back in after a newer one read wrong). It has a 170 degree stat.

For awhile I ran a brass replacement radiator as the original one got damaged. This created an overheating situation when stopped in traffic. A few years ago I replaced it with a DeWitts. The fan is an aluminum flex-fan with deep blades. On the highway when its 80 degree+ it runs dead on at 170 degrees. In the worst of traffic stopped for a while it might climp to 200, but as soon as the car moves and gets air flowing it goes right back down. In cool weather the car runs consistently below 170 degrees. The car had a 13lb cap.

I've noticed some recent postings saying it can't be a thermostat as once it opens there is full flow no matter whether it is a 170, 180 or 190. This "assumes" however that it is opening and closing at the correct temperature. It's possible, for example, that the 180 stat senses wrong and "thinks" the engine is running too cool so it closes up some eventhough well over 180 degrees or more. Thermostates are cheap and should be one of the first things to check and replace

0Tom@Dewitt

First, I appreciate all the testimonials. You guys are very good too us!

Second, I want to caution the group on crossing over C1 vs C2 when talking about radiators, especially our (DeWitts) radiators. You see, in the past when someone said "A DeWitt Rad" it could only mean one kind. That being a plate type "restoration" radiator used in 1961-72 small blocks. 3150916 or 3155316.

We now have a whole new line of radiators called "Direct Fit" which includes (11) eleven different units, covering 1955-2004. Some of these "Direct Fit" radiators match the same application useage as the "Restoration" radiators. So we have two for the same cars.

Often I see a thread from an early C1 member (as done here) asking for advise and most of the comments and advise do not apply. 1953-60 cars used a whole different style (copper/brass) radiator than did the 61-67 cars. These radiators can be cleaned, re-cored, and repaired where aluminum radiators used during 1961-72 cannot.

When someone says the radiator was "re-done" it could mean anything, from replacement to a new paint job. Who knows? The original core was refered to as "cellular" which is very similar to how they make the heater cores. Most radiator shops today will not put a cellular core in because they are more expensive and don't know where to find them.

I have a typical list of questions I ask anyone that calls me, the most important one of all is "what year"? Then I know exactly what model radiator we are talking about. Here's the one's to follow:

How hot? What temperature? Does it boil over? (If yes, this one eliminates the IR gun) Driving? Idle? Ever confirmed these? Do so! Vacuum functioning? Water/anti ratio? What radiator? Age? Type? After these are answered, 95% of the time we find the answer. You'll never solve anyones problem by telling them what you did for some other car. Even if they are the same year and engine.

Ok, re-cap. DeWitt Models are:

Restoration line 1961-72 plate type originals (Two models)
Direct Fit line 1953-2004 tube type replacements (Eleven models)

Here is the Direct Fit for the 1955-60 (BTW, it's actually cheaper than a be-cool and it fits better.)

Denney

I have to agree with Duke, it could be ANYTHING and just buying a new radiator may not have any effect what-so-ever (except lighten your wallet significantly). For instance, vacuum leaks (if bad enough) can cause all sorts of lean burn issues, and that means running hot, so how about a little more info before we jump the gun here...

GCD1962

Tom - What is the difference between a celluar core and the core most radiator shops use - how do you tell the difference and how much of a difference on the cooling?