Well I started having some cooling issues with my 69 RR built 440 with cooling last year. Problem would occour when the ambient temps were about 75 or warmer. A few days ago I drove in 55 degree weather and it started getting hot. I do not currently run a thermostat in the car. The thing that has me confused is that there was so much pressure in the upper and lower hoses I could not even squeeze them a small bit. Tested the cap and the cap actually tests bad but for not holding enough!! Water flows like crazy when I had tested this before. Is it time for a new radiator? possibly aluminum? If so is Smith's a good brand?? Thanks I know multiple questions!!!!

Cooling problems come from more than just radiators, what is the timing set at? Is it rich or lean? Maybe the water is running water too fast thru the radiator try running a thermostat.

BTW Lodi apples are the bomb!

you need to run some type of stat. helps slow the water down and gives it time to cool thru rad. the other thing I learned is you want the motor to run at a constant temp and with a stat it regulates that. You aren't running straight water are you?? that's a no no .

Why no thermostat? I'd put one in there before buying a new radiator. Put a 195 in there and I bet it's better.

Another thing that causes cars to run hot is tuneup, not enough timing or fuel. One or the other or both.

The stiff hoses makes me think possible slight combustion leak into the cooling system (head gasket). I'd highly suggest a stat but that's not what's causing the problem at hand

I didn't want to tell him that.

Ok looks like I need to run a compression test. This car has the timing perfectly set and I run a restrictor in the system (basically hollowed out thermostat) Looks like I will be running a compresstion test. This problem seems to be getting slightly worse as it goes on. Thanks for all the advice.
PS mix is 50/50 perfectly

First thing we have to know is how hot is it??? What kind of gauge do you have on it? Are the hoses hard to squeeze after just a few minutes or when it's at operating temp? How old is the radiator? Is it the old clogged original or is it new?
Sorry if I didn't see any of this information listed but we need ALL the facts to make a correct diagnosis instead of just spit-balling possible causes.Over heating to me is 230 degrees without coming down
Gus

Can you take the car to a local radiator shop? They should have the gizmo that attaches to the radiator cap port, and will test for compression gasses in the coolant.

You may not be able to see the leak with a compression test.

Oops sorry forgot to list a few things. Well the car seems to run great at 180 but then when it hits about 185 it will start to contunue to climb sometimes as high as 205. That enturn gives me fuel problems and then I have to sit and wait after it stalls out. The pressure seems to be fairly soon after it runs I had never noticed it before. It is the old steel radiator that is in it.

OK been working a ton lately. Got out to check the car and NO COMBUSTION GASES!!!! YAY!!!! So I have good headgaskets. I am getting a white looking foam and I do know the coolant needs to be flushed but I had just done this last summer and it is already rusty. Im guessing Im just having major radiator issues. OR am I wrong??

I have to run a 160 stat in mine. A 195 makes it overheat.

hot in traffic or down the road ?

Currently just have a restrictor no stat at all. And it is worse when stopped but will do it while going down the road as well.

Are you having an issue with it hitting 205 or is it that when it gets hot enough to stall it happens to be at ~205? as 205 ain't terrible. Are you running gasahol (10% ethanol alcohol) which can act up at 205. plus alot of temp gauges are not dead on accurate. I would toss the restrictor & use a 180/185 stat & if the real problem is the stalling then we can attack that. More info please. & does it get to 205 & shut down or does it get ever cooler on the highway OR around town?

205 happens to be where it stalls out. it will start getting up to 200 at 55mph on a country road at 75 F outside. I usually run 93 oct. with no ethanol mixed with half tank of 110 oct. This car just seems to run great at about 170 and I have checked calibration on my guage and it seems to be really close.

Alright, I'm assuming the mixture/timing are in the ballpark. Overheating at speed is a water flow issue unless the grill setup is extremely restrictive blocking airflow which is rare & I dont think thats the case here. I would toss the restrictor for 1 day which will tell you if it is restricting water flow too much. I'm assuming the lower hose ain't collapsing. Sounds like it may need more radiator (not enough capacity or partly restricted). Seeing good flow at idle can be misleading. Holler how it goes. PS good to hear no combustion gasses

Ill get rid of the restrictor this weekend and let everyone know! I really appreciate all the help! Both hoses were building pressure. My money is now on a junk radiator and thinking of going with a Smiths.

My original 3 row core OE 65 dart SB rad sprung a leak & a tin of coarse ground pepper from the Quik Shop on the way home fixed it for a year! then it sprung another leak in another location so I bought an eBay Champion 2 row direct fit aluminum radiator & I had to redrill 1 mounting hole on one side & it cools good (nothing to brag about on a DD 318 though) & no leaks & was ~ $189 iirc including shipping. I'd by another Champion rad in a heartbeat

Cab I really apriciate old school tech like that. Its sad how you cant get info like that from many buisneses now days.

I suddenly began running hot. Got worse as I was moving. Bypassed heater core. All good ever since. Never bothered to replace heater core. Don't need heater in Stygia most of the time.

HotRod, you're jumping on the wallet quicker than necessary.

First, if your car can't run at 205 degrees then you have a tuning issue. Old car guys get nervous around 200 degrees for some silly reason. There's no need to worry unless the engine can't keep itself under 220 degrees. Yes, that's hot enough to boil water but not when it's under pressure (radiator cap).
You say your car is perfectly timed. Timed to what? An abstract number that someone gave you after reading your build sheet? Maybe it's timed for best performance over a 1/4 mile? If you're timed to performance it's likely okay. If it's times to a guru's magic number it's very likely you're in the ball park but not really perfect.

Now, before you stomp on your wallet and throw cash around needlessly, try a few things first.

Do you have an IR thermometer?



If not, go get one. They can be had cheap through Northern Tool, Harbor Freight, and a ton of other places. They're great for measuring all kinds of things like cooking oil, HVAC, home insulation, heat sources inside the car, and a billion other applications.

Use it to check temps across the radiator. If you do not see a 30 degree drop in temperature from the inlet to the outlet there is a problem.
Shooting different parts of the radiator will tell you if it's in good shape. If there are cool spots you know that area is plugged and service is required.

It can also be used to compare cylinder head temps as well as exhaust manifold temps to identify any part of the engine that may be faltering. Use it to check the carb temp too. As stated earlier, new fuel formulations don't tolerate heat very well.

Grab the temp gun, check those things, and get back with us. Maybe you can figure out the problem without wasting money.

are u running a clutch fan or electric? if it a clutch fan ck that as well, and do u have a shroud on it? and install a stat.. and im glad its not a head gasket..

Did the IR check and its only about 5 degrees drop. I plan on putting some kind of stat in it when I do get a radiator and I am seriously thinking of replacing the heater core at the same time. I cant remember off the top of my head what it is timed at but I do know I have it spot on. Runs rough when adjusted either way. The fan is a clutch style. With a shroud.

Did you measure the radiator or the hoses close to the engine? I assume the engine was running (as it should be).

If there is only a 5 degree drop across the radiator you have a big problem. Did the radiator have a bunch of colder spots in it? If so, it needs to come out.

Even if you don't have a fan running there should be more than 5 degrees of temperature drop across an open radiator.

My other input is some blocks have a lot of "sand" in the coolant jackets. This sand clogs the radiator but is fluid. It's a far stretch but I did not see what engine you had or the history of that engine.

A thermostat is VERY important and also weak coolant will not carry as much heat away as 50/50 mix of good quality. Yes you can run straight water, but if it is boiling over because the temp is hitting 212, steam is a useless transmission of heat.

The proper water pump (and pulley combination) also plays into the mix. If your hoses are hard, then try it with a loose radiator cap (after it cools of course. Don't burn yourself). If the car will not keep the antifreeze mix in the radiator and violently pukes over sitting still then you have lack of heat loss issues. I.E. cavaitating water pump, blockage in radiator or blown head gasket(s) Is your water pump belt slipping?

I guess with out sounding all over the place, I kinda do that... start with the basics and work from there.

Also a post earlier asked about anything over 200degrees and old timers getting nervous. it was because the factory head gaskets and bad machining would cause leaks over 200 degrees. Honestly we have come so far in the last 40 years that we don't even remember those days. I caught the tail end of carburetors on production engine as a professional mechanic. There was a lot of those type of "rules" that are just fairy tails now. The other was a noisy rear axle... install a few banana peels to quiet it down.

Good luck with your coolant issue.
Happy Memorial day to our Vets!
Thank you for your service.
Joe

I had measured closer to the radiator. and there seems to be a cool spot right in the middle. roughly 10 to 15 lower than the rest. This car use to run at 180 all day now its getting hot. The engine is built and was done atleast 20 years ago. So im thinking the sand sould be long gone. Thanks again for all the help. Not too many 23 year olds even mess with the cool iron anymore.

Good to see a fellow Wisconsinite! I live just down the road in Madison. Here is another thought, make sure you have the proper radiator cap... This cam cause issues too. Good luck

Mike