69 roadrunner overheating questions

[Butch Harley]

THANKS for everyone's help

 

[toolmanmike]

My RR is a pretty stock 383 with a 7 blade fan (from a 72 cuda?) stock water pump champion radiator I think 4 core and a 16"pusher fan I also vented the hood(pics). Motor has a classic air system AC. 1- at +80-90 degrees when moving - temp is 185-200 depending on speed in traffic dead stop it will hit 230 in about 15 minutes. So I think the fan is not adequate would a Be Cool system solve my problem? 2- I am running a 60amp alternator is that big enough when AC & fan is on dash gauges are peg to C. Also when running idle just engine fan a Anemometer wind speed recorder the best is 3mph with pusher fan on also 6-10mph depends on were you put it. THANKS in advance for your comments. View attachment 1493264View attachment 1493265

I don't see an issue with the temps. A 180° T stat will run 190+ in traffic. Idling at a stop for 15 min with the temp rising to around 230° is fairly normal for a system like this. Heating and overheating (puking coolant out) is 2 different things. A factory temp gauge with no markings and a overflow tank system, you may never know the temp is getting that high. Remember, water boils at 212° at sea level. Every pound of cooling system pressure raises that boiling point 3°. a 15# system gives you an extra 45° before boiling. That's why it doesn't puke coolant out at 230°. You already have a good sized aluminum radiator with a shroud, a good sized fan, and a electric pusher. Like suggested, double check your tune and may be try removing the shroud to test. Trim it as necessary to make it right.

 

[Hemirunner]

turbine it is a MSD ready run 3 wire I will try it THANKS

I’m assuming the Vacuum advance is hooked up and functioning? Is it manifold or ported? How much timing at idle with the vacuum advance?

 

[Butch Harley]

Toolman I preform test in the driveway on days like today 90 degrees when it hits 230 I run it down the road for about 3-4 mins cools it down. If I shut it off we have puking! the problem in NJ you can sit in traffic a long time do not want to cook it! Also I have mechanical gauges.

 

[Butch Harley]

Hemirunner (I wish) but vacuum hooked to center carb 10 degrees adv @ 900rpm

 

[WileERobby]

WileE I had a stock 26 in before the champion

And what was the issue then ?

 

[toolmanmike]

Toolman I preform test in the driveway on days like today 90 degrees when it hits 230 I run it down the road for about 3-4 mins cools it down. If I shut it off we have puking! the problem in NJ you can sit in traffic a long time do not want to cook it! Also I have mechanical gauges.

If you shut it off and it pukes you have a pressure loss problem. Probably a bad cap. My Swinger would do that on hot days running the A/C.

 

[Hemirunner]

Hemirunner (I wish) but vacuum hooked to center carb 10 degrees adv @ 900rpm

There’s a good chunk of your heating problem. You need more timing at idle.

 

[Demonic]

Maybe the pusher is blocking the airflow too much? I’ve posted a bunch about the virtues of the EMP Stewart thermostat, with it’s larger opening and corresponding flow.

 

[mrmolding]

I had a Classic Air system on a formerly owned 68 Road Runner. Took me a while, but I went back to all pretty much stock. I flushed everything out, got a clutch fan from Tony's parts, NOS thermostat, got a max cool radiator from Glen Ray, etc. But when you look at original motors from the factory with and without AC, there are cam differences etc. to handle the load of the AC system. It had a 70 440 with a very lumpy cam (done by a previous owner), and I could not get the motor to love the AC load on hotter days. Then I'd suffer vapor lock and finally fixed that. In time, I got everything fairly sorted, but did resort to the old trick of turning on the heater to cool down the motor like in the old days.

Wanted to mention, that the car was on the east coast and west coast of the US. It got very hot on 90+ degree days on both coasts before my fixes. Over 100 was when I needed to turn on the heater.

 

[dadsbee]

I have 5 cars from 340's to Hemis. Some have timing locked. Some have stock vacuum advance. Every one of them runs a stock radiator and a 190 stat. My 383 car is stock fixed 7 blade fan and no shroud. All 5 cars pop the stat and run there. Creep to 200 210 if sitting. First get rid of that pusher fan. If that doesn't do it put a real radiator in it.

 

[RJRENTON]

I don't see an issue with the temps. A 180° T stat will run 190+ in traffic. Idling at a stop for 15 min with the temp rising to around 230° is fairly normal for a system like this. Heating and overheating (puking coolant out) is 2 different things. A factory temp gauge with no markings and a overflow tank system, you may never know the temp is getting that high. Remember, water boils at 212° at sea level. Every pound of cooling system pressure raises that boiling point 3°. a 15# system gives you an extra 45° before boiling. That's why it doesn't puke coolant out at 230°. You already have a good sized aluminum radiator with a shroud, a good sized fan, and a electric pusher. Like suggested, double check your tune and may be try removing the shroud to test. Trim it as necessary to make it right.

If you have a 50/50 mix of glycol and water as the coolant, it contributes to increasing the boiling point when under 15# pressure. As for the coolant temperature increase when operating at low speed or idle conditions (low water pump RPMs and subsequently low volumes/ velocity) with high ambient temperatures.....this is attributable to the slow velocity of the coolant, in the engine and heads combined with slow coolant velocity in the radiator....regardless of construction....as I've preached b4, largely to deaf ears or lack of understanding, velocity of the coolant is the secret to efficient heat transfer, the faster the better, as you are moving BTU's from the heat source (engine) to the heat exchanger (radiator)...this is in spite of anything your "buddy" says.....it's a fundamental aspect of thermodynamics. Sounding like a broken record.......
BOB RENTON

 

[Demonic]

One thing about radiators - they're more dirtier on the inside than you think.

 

[cosgig]

View attachment 1493288
what you are looking at is a coolant filter in a heater hose that was blocking coolant flow to a heater core. when i installed my champion rad it ran 180 to 190 in Florida heat then it started to run in the 220 to 240 range so i drained the coolant to fine all kinds of rust chunks in the tube of the rad witch hurt coolant flow so i bought a coolant filter for the upper rad hose and a Griffin rad then drove 120 miles when i checked the filter it was jamed with rust chunks i removed it and cleaned and it has gotten less as time has gone buy . take it for w i w and install a coolant filter to keep rust from plugin the rad tubs. this picture is from one of my fleet trucks but it shows' what i had with my coolant filter.

I want one of those….or maybe 3-4. One for each car.

 

[vance.dykes]

I want one of those….or maybe 3-4. One for each car.

hear it is

Amazon product ASIN B07C42VP5G

 

[Butch Harley]

THANKS for all your reply's have not a chance to work on it when I do I will post my findings thanks

 

[jag_mopar]

I found that some aluminum radiators have narrow tubes (champion) that transfer the heat. Some manufacturers offer larger tubes that will provide faster greater flow through. A combination of problems may be occurring. Get a Hiperformance water pump with more blades. Get a high flow thermostat. Fan clutch that is functioning and spaced properly in the shroud. Remove any pusher fan may be restricting flow. Also look at if missing the gaskets at the front and rear of the hood. They do aide in air flow direction. The open hood vents may change the air pressure under the hood which may restrict flow. I have had to close off the opening of a 6 pack style hood to flow properly.

Flush the radiator and block the best you can using the pipe and freeze plugs on the block. Use a pressure washer or what ever is available. They also make a flush or I have used muriatic acid on my old /6 to loosen things up.

A lot of things to look at. Good luck

 

[Road Grabber]

Throwing something different out there to consider.

You mentioned rust clogging up your cooling system filter.

Before you installed the filter that would mean rust particles were accumulating in and around your cylinder walls in the block water jackets. This will prevent coolant from flowing around the bottom portion of the cylinder walls and if bad enough pile up behind the freeze out plugs.

If you want to know the condition of your water jackets I would pick one easy to remove and replace freeze out plug and remove it to see if rust has piled up along and around your internal cylinder walls. You might see gunk right behind the plug. In fact they might be about to leak through.

If you have junk clogging the passageways it doesn’t matter how much you update or repair the rest of the components. Your engine will overheat no matter what you do. Even if you drop your lower radiator hose and flush it still won’t flush out the heavy crusty rust around the bottom of your cylinder walls. The rust gets so hard you can take a screwdriver and have to loosen it up.

If you ever disassembled an old engine with old brown coolant you will know what I’m talking about. You should not have had brown coolant in your system. By the time you see that rust a lot has accumulated throughout your system and engine water jackets.

Good luck

 

[Butch Harley]

Too far into the shroud is a problem.
The fan tends to circulate the same air within the shroud instead of pulling it through the radiator.
I'd try removing the shroud completely as a test or cut it so the fan is halfway in there.

Hi Don I removed the shroud after reading all about fan/shroud placement and it was in a bit but removing it was worst. THANKS