Overheating Issue

[JayBee]

A friend of mine had some luck once fixing a console with that plumbers goop they use on PVC pipe 

[bb71challenger]

You can rivet it or even try JB weld with the thin metal like you were thinking anyway. It is almost complete and not broken in multiple places so you got really lucky. And for a bonus the break is on the bottom where it will not be seen easily. You will be amazed at how much difference a shroud will make. Unless you have silicone floating around in your system I would put money on the shroud fixing your problem totally.

[miketyler]

I too have overheat problems still to this day with my 340. It was apparent right after the restoration was completed. I hit it from all angles. Hoses, tuning, water wetter, etc. One of the last things I did was remove the underdrive billet pulleys. This improved things a little but its not rock solid as it should be. Am running a FlowKooler pump, 26" radiator (recored to 4core) belt driven OEM fan with shroud.

I dont want to distract from your issue but am very interested in what you find relative to flow. Like yours, mine doesn't show any marked flow at the radiator cap when its running.

[bb71challenger]

I know one thing I always heard about hot running 440's were the tightness of the bore in relation to the piston. In other words if the machinist keeps the clearances too tight then the friction causes overheating problems that dont go away. I am sure it is the same for most engines too. This same guy always told me to build a 440 just a tad on the loose side to keep the overheating problems from appearing.

[RDF]

I'll definately keep everyone posted as to what is happening as I try/add things.

One thing about today is, I took it to work and the whole way in it was 180, steady....now it was also 55 degrees out this morning, so I'm sure that helped, but tonight when I drove it home from work, same thing until I hit a red light about 15 minutes into my ride.  It was a long light and the temp rose to about 200-210, then once I was moving again, it shot back down to 180-190ish...strange behavior, especially since it's never done this before.  

I think the new, non-flex upper radiator hose helped some, but it's probably more of the placebo effect rather than anything....

[farmertan]

remember fan to shroud placement is important too for the most air flow i think you want the fan blades just inside the back edge of shroud.

[bb71challenger]

You are not getting good solid flow through the radiator at the stop light and that is why you are overheating when stopped in traffic. The symptoms are identical to mine when I did not have one installed.

[MoparManiac2008]

We had temperature problems in our 70 cuda, we tried everything...but what fixed it was a new radiator cap. if you havent tried that yet i definitely would. Just my 

[Supercuda]

The problem sounds like one of airflow. The temperature creeping up at the light is a good sign of this. The flex hose disturbs the flow of coolant, and slows it down, also causing unwanted turbulence and flow restriction, due to its ribbed inner surface. The shroud will make a huge difference, as it stops the airflow at the outer ends of the fan blades from being "recycled". It is one of the first things I was taught about airflow around a fan blade. At the tips (and for as much as the first 10% of the length of the blade!), airflow is circular, simply being spun from in front of the fan to behind it, and back again. The shroud, if properly placed, prevents this. The fan must be at least halfway into the shroud, and no more than all the way inserted into it. Install the fan too deep into the shroud, and you do not fix your problem; install it too shallow, and it does not fix the problem. Install the shroud before you do any other big changes to the system- I think it will fix the problem for you.

[Aracer]

Overheating is hit and miss, and is different for every car, due to compression and cylinder pressure variances.
     I like a light thin 18" aluminum flex fan Perma-cool #83181, set at 1.5" from the surface of the Rad. I used the 2.5" spacer #51197/ Jeg's for the adjustment, without a shroud. For me the shroud "sez, smog device" because it shrouds the Rad. in order to warm up quickly. They are ugly and noisy too.  The fan shroud doesn't really make much of a difference if the set up runs cool anyway. Shroud's funnel the air from the Rad. center at high speeds because the opening is smaller, the air coverage is incomplete. 

[71chally416]

Wassup with that giant bolt sticking out over the water pump pulley? 

[miketyler]

I am guessing its a belt guard. 

So it sounds like an air flow issue and you really should try the shroud. The one offered up here is a VERY easy fix. I fixed mine with a thin aluminum doubler, bonded and shot aircaft AN rivets thru it.

So what about flow as seen at the top of the radiator? Is this a key? These radiators are down-flow, not side-flow like newer radiators so maybe no visible flow at the cap is not an issue? 

[Bullitt-]

So what about flow as seen at the top of the radiator? Is this a key? These radiators are down-flow, not side-flow like newer radiators so maybe no visible flow at the cap is not an issue? 

When the heat is up & the thermostat opens you know it... you can see the coolant moving rapidly across the filler neck...  My car takes much longer than the 15 minutes, I see referenced, to come to full temp. 

[RDF]

Still waiting on the shroud.....he sent me an email and said he's been busy lately, which I think everyone can relate to, so I'll wait patiently....    

[Aracer]

Wassup with that giant bolt sticking out over the water pump pulley? 

It's an invention. So the belt can't fly off the pulley, it doesn't touch unless the belt tries a wheelie. I'll have to chrome it so it fits the decor (damn critics) .