160 will just open fully sooner than a 185....if you are hitting 220 temps either stat would be fully open so your cooling system is suffering elsewhere.

Do you have a fan shroud?
how many blades is your fan?
What condition is the radiator in? (read has it ever been flushed and do you know it is not clogged some)

Temps today are within a few degrees of what these cars were 50+ years ago and they didn't overheat in summer with properly functioning cooling systems

 

Yes i have a fan shroud, 6 blades on the fan, condition has ~8,500 miles on it but is roughly 7 years old. Not sure if it's clogged, but I've had this temp issue since originally put it and the engine in about 6 or 7 years ago.

 

Danny, What mods if any have been done to the engine? Running air conditioning?
Driving in stop and go traffic? Does the temp drop when moving allowing more air flow?

 

No mods, stock 350. I do have AC but typically drive with the top down so I rarely have it on. I typically don't have it on at all during the hotter months because I do notice the temp increases quick. Which sort of defeats the purpose of an AC.

and yes mostly stop and go traffic around town, i do not notice it drop when moving. It usually just creeps up to just under 220 and stays there during the duration of my drive.

 

A SBC with stock shroud and fan (about 1/2 in/out of shroud) with a 185 stat should not have a problem overheating. Yeah it will run hotter in hot summer days at 200-210 in stop/go traffic but that is not a problem. Temps should drop back down to 185ish once you get mooving

You verify the temp gauge using a IR temp gun to compare?

What is your timing?

you sure you are also not running lean?

 

I have not tested it with an IR temp gun, it is possible the temp gauge is just reading incorrectly.

Not sure of my timing and if I'm running lean or not.

 

If it is a clutch fan, how old is the clutch? It is possible that it needs to be replaced or rebuilt.

Here is an interesting article: https://www.popularmechanics.com/cars/how-to/a302/1772922/

 

Fan clutch was replaced with engine and radiator about 6 years ago/8,500 miles

 

220 is pretty much the top I would be comfortable with but if you're not puking.
coolant I wouldn't sweat it. Have you ever checked the accuracy of your gauge?
I use a hand held infrared thermometer to check my engine temp after a drive.
I check the upper and lower radiator hoses and the thermostat housing. Kind of
a piece of mind thing. Given the area you're in and the type of traffic you're probably
not going to improve much without throwing a lot of $$ at it. I spent the winter in Mesa
so I'm aware of the traffic.

 

AC car should have a 23" radiator

 

Yep have that, shows just about 25" end to end

 

Danny, The temp of the upper hose will be higher than the lower hose by ~25*
if the system is working correctly. The temp at the thermostat housing will be
the highest of the 3 and should be within ~10* of your cars gauge assuming
your gauge is tapped into the manifold just under the housing or in the housing.
With IR guns different materials can effect the readings. Rubber vs. steel vs. cast.
If your sender is in a cylinder head the gauge will probably read a bit higher yet.
Seems that's what most have found anyway. I basically look for the difference
between the upper and lower hoses and then verify the housing isn't higher than
my target temp of 200* max. This is just my experience.

 

I will add when you get an IR Thermometer take readings at different areas all over the core, be sure the cores are clean and free from dirt/grime. If the temps vary widely that tells you some tubes may very well be clogged. I have seen crap get in there and have also seen solder particles from a poor rebuild job accumulate in tubes.

 

Harbor freight sells cheap useful IR guns.
As suggested, do all the above. Radiators are only going to cool, by design, 20°F between inlet and outlet.
With engine off, you could feel the backside of rad core feeling for cool spots.
The AC condensor and radiator could use a good rinsing with the garden hose removing debris/bugs from the fins.
A working clutch fan will lock up at a cold start-up then release, you should hear the fan noise, then the noise will go away after about ten seconds or so.

 

So this is what I've done. I borrowed a temperature gun from my father (it's made for food by the way) and after driving the car around for about 15 minutes in 90 degree heat both the upper and lower radiator hoses read about 10 degrees apart from each other, lower one being about 168 degrees and the upper being 175. At the time the temp gauge was reading just above 180, maybe 190-200. The thermostat was reading ~208 degrees. The fan was running the entire time.

So I'm not exactly sure what to take from this. It seems like the temp gauge is fairly accurate given the thermostat was around 200, and the temp gauge was in between 180 and 220. Then again I'm not sure if my temp gun was the most accurate since it's made for food, I still might try and buy a IR temp gun from somewhere, doesn't seem like Harbor Freight sells them.

I'm still leaning towards just replacing the radiator, I'm not sure if its really the issue but I feel like a newer aftermarket radiator might make a difference.

 

Danny, Your temps are very close to mine. Only real difference is I get ~20* difference
between upper and lower hoses most of the time. I would flush the radiator and change
the thermostat before replacing the radiator. It's possible your thermostat isn't opening
fully. Replacing it is cheap insurance.

 

Should i go with a 160 or 180? Or does it really matter. I'm researching the differences now.

 

I would go with 180. As I think about this, your thermostat may be fully opening too soon
rather than not fully opening. The thermostats job is to hold coolant in the radiator to give
it time to cool. Original factory spec for a 180 thermostat is start opening at 177*-183* and
fully open at 212*. If you can find a 185 I'd go with that. 5* doesn't sound like much but it
can have an effect.

 

Great thank you, it actually seems like 195 is the more common one I'm finding, haven't seen any 185's yet. I'll go with 180 since i believe i have a 195 in it now. And I'll flush the radiator/put new fluids. Thanks for the help!

 

Question not answered: what is the full timing scenario? Initial, vacuum advance, ported or full manifold vacuum, mechanical curve, starts and limits when?

 

Honestly I'm not sure how to get any of this information.

 

Do you have a two or three core radiator?

If its a two core, I’d go with a three core- it’s more efficient.

Good luck!!

 

How can I check this?

 

Two rows with large tubes >1” should cool better than a three row with smaller tubes.

Don

Edit: corrected with Scott’s input... :grin2:

 

A radiator consists of a core and within it are rows. No such thing a 2, 3 or 4 core radiator.

 

I meant rows. Thanks for the input as always....

Don

 

It doesn't matter what thermostat you put in. Your engine will eventually try to get to its normal operating temperature. No stat will just take longer. In cold weather you want your engine to warm as quick as possible, that is why the factory put a stat in. The factory stat was 195*, so your engine will run approximately plus or minus 190* -200*.

 

How deep into the fan into the shroud? It roughly should be half way in and out. Short water pump needs a different shroud than a 69 with the long water pump. Try fresh coolant flush and fill, new 180* thermo. Make sure the thermostat is inline with the flow from the hose. (Might be an old mechanics tale but I always do it)

Oh and is it a high quality radiator?


Sent from my iPhone using Tapatalk

 

I would wonder if you are too advanced on your timing. Does it run on? Is it running lean?

 

SO I am also having some heat Issues. Trying to do some research. If the Car Runs on after its Turned off dose that indicate the timing is to advanced? Mine dose that sometimes but not every time. I have a BBC

 

I was running a 180 in my 68 454 4spd and stayed around 190-200ish. I switched to a 160 and now stay 175-180ish

 

I was just trying to learn what I could from whats here already - I need to do a little more research and I will start one after that. Thanks for the reply

 

Not trying to discourage you at all from learning. Sometimes these threads can go off on another's problem and then back to the OP again, etc. Makes it tough for anyone to get a good resolution to their problem.

 

Difficulty turning over is another indication of a lot of timing advance.

Also, I recall poor cooling capacity with a flex o lite fan - I chucked Mine in the garbage and replaced with a viscous clutch fan.

 

mine turns over easily and starts easily. I am at 36 degrees TT @ 3500 rpms ( I need to verify this again but that what I remember.) I do have the blades open a tinny bit to keep the idol correct which may be a factor in my case. That's why I need to re-examine the Idle

 

It appears that Harbor Freight has run out of IR Thermometers due to COVID-19. They are so popular, they are hard to find in stock anywhere. Here is one on Amazon; IR Thermometer

A 1"-1-1/4" Tube 2-Row Radiator will most definitely cool better than a 3-4 row radiator.


Arkangel77; It is better for you to start another post with your issues and to stay on point in this post to the OP's issues.

Brett....