cooling issues

[sidewalkman]

As you know our Birds run hot, I've added a flex fan with spacers to get it closer to the rad, flushed the cooling system and pulled the rad to straighten every fin, still ran hot when stopped, did the 160 degree thermostat switch, still would get hot when stuck in traffic.

I then added the bottom parts (mostly because I thought the top would be included) of the 2 piece fan shroud off a Bullet Bird. There is no real place to mount it except at the bottom of the rad where I made a mount but after strapping it in place, even without the top portion it made a world of difference, car never gets over the M on the gauge. Yesterday I was sitting for 45 minutes in traffic on the way to a gathering and perfect.

The other thing I did was get the draft tube replacement piece from John Draxler at TBird Ranch, and plumbed it into the underside of my air cleaner where I originally had a put a pipe from the oil cap breather. I have shiny chrome valve covers with breather in them so it was un needed. Now where if sitting in traffic staring at my temp gauge and watching small bits of smoke waft up from the passenger side draft tub I now can listen to tunes and not worry about either.

[Tbird1044]

I've gone through most of the same changes as you did, however, I bought one of the aftermarket fan shrouds. I changed the location of the flex fan accordingly to optimize cooling. It seems to do okay now, but like you stated, it does climb to the top of the "M" in stop and go traffic. When I check the radiator and water outlet on the block with a temp gun, it appears to be around 205-210F. I can live with that with a 50/50 antifreeze solution. On a 80F day, with the AC on, it may even sneak up a little hotter. I even changed my water pump, as I thought I might have some erosion on the impeller. I took my old pump apart, and it looked fine. Sometimes I wonder if that pump just isn't providing enough circulation at idle? I know the electric fans are still the best solution, but that also involves changing the generator to alternator. It's always something.
What was the outside temperature when you were stuck in stop and go traffic?
Nyles

[DKheld]

Been chasing cooling issues too. Think some of mine is from the shop not cleaning the block properly when the engine was rebuilt. I bought the engine from someone but had no info on the build. Runs great though - probably should have just rebuilt the original (which I still have) but it was 1/4 of of that cost plus it had rebuilt heads.

I'd love to see my temp gauge stay around the "M" mark. My old engine would barely climb to the M and sat at the E most of the time. Moved the old temp sensor to the new engine so know that is not a factor in the temp difference. The new engine runs mostly at the top of the M but I make an hour trip often that involves climbing a winding mountain road - 35 mph. Temp climbs just past the P. On the way down the temp falls to the E. Outdoor temp is 5-8 deg cooler at the top and coming down the other side. Outside temp that day was 85 at the bottom of the mountain and about 80 up top. Forgot my IR temp gun so don't really know what the engine temp was at the "P".

I've even installed a HUGE flex fan from a Ford 400 ci engine. Thing sucks massive air at idle but gets nice and quiet on the interstate with no overheating. And - honestly - it never overheats (or boils over) - I may just be watching the gauge too much and comparing it to the old engine but I want as much cooling as possible for the A/C install.

Original / A/C style / Flex fan


Here's what the flex fan looked like when I was test fitting - had not yet painted it white. Used a flex-a-lite spacer, new radiator, water pump etc.



I did change my thermostat recently (I'm making another thread on that ) but anyway it seems to have helped. Temp still goes to about the center of the M but pretty much stays there now. Looks a bit like my original (and I mean the one that came in it new) T-stat may have been stuck open. Only climbed to just before the "P" last trip up the mountain.

Will probably make a shroud. Can't see paying the price asked for the new plastic ones. The plastic shrouds for the MG's I work on are roughly $50 and since the Tbird is double the size maybe $100 but not $200 - that's crazy.

My new engine which is a '64 has PCV - that is a nice system over the road draft.

Eric

[StealthSRT10]

I had the same issues with heat in traffic down here in Houston, Tx. I added the 6 blade flex fan and it moves alot of air but the oil cooler did help i have to say.

[Carolina Tee Bird]

Question for anyone but reacting to comment from Stealth. You mentioned adding an oil cooler and that helped the overheating situation. Please elaborate on that, where did you get it and how complex was the install. I see you are also an apprentice. Also for anyone to comment.....purchased this car with rebuilt 390 but it sat for 7 years after rebuild. I too suspect sediment restricting coolant flow. Any recommendations on how to do a thorough flush? Already have new 4 core radiator, new thermostat, new shroud and new 6 blade fan though not the flex type. Still over heats at stop lights but cool cruising down the road. Considering changing to Evans waterless coolant as asked for help in previous post. Thanks,
Hot and Tired

[scumdog]

Staying cool while driving along but getting hot when waiting at stop lights points to one of two things:
(A)insufficient air-flow or
(B)insufficient collant flow.
Both when motor at idle.

(A slim third possibility is timing being too retarded)

To get heat fuel must be burned and at idle there’s minimal fuel being burned so back to A and B to be checked out.

[Penelope]

. Considering changing to Evans waterless coolant as asked for help in previous post. Thanks,
Hot and Tired

I run Evans WC in both my birds now, they both have aftermarket AC fitted and this has stopped the overheating issues. I did flush the blocks and radiators with a 2 part solution we can get here in Australia, www.liquidintelligence.com.au . I think that it was a must if you go to the expense of the waterless coolant.

[simplyconnected]

Staying cool while driving along but getting hot when waiting at stop lights points to one of two things:
(A)insufficient air-flow or
(B)insufficient collant flow.
Both when motor at idle.

(A slim third possibility is timing being too retarded)

To get heat fuel must be burned and at idle there’s minimal fuel being burned so back to A and B to be checked out.

Yep, there's more to it than that. If your engine was neglected and the head gasket coolant-holes are rusted through, little or no flow gets to the rear cylinders. In other words, coolant bypasses the rear cylinders.

If your heat riser valve is stuck shut, that will cause overheating.

If some radiator cores are loaded with lime/calcium, that will diminish cooling capacity.

Years of crap at the bottom of the cylinders (behind the freeze plugs) will also displace coolant.

I get a kick out of all the different methods people use to get around the root cause of overheating. When these cars were new, they were built to cross the desert and the Rocky Mountains with no issues. They didn't have six-blade fans, quadruple row cores or aluminum radiators, etc. Some pulled trailers using conventional coolant.

I will concede that Squarebirds were designed and built to burn LEADED gasoline, that inherently runs cooler because lead helps as a lubricant. We can fix this by using modern engine-building methods and materials. After all, modern cars don't overheat using the same fuel. - Dave

[Dakota Boy]

I fought cooling issues for a number of years before dropping some cash on a new 4-row triple pass design from US Radiator. Problem solved. Perhaps a new 3-row replacement would have been sufficient, but I'll never need to think about it again.

[Carolina Tee Bird]

Appreciate all the comments. As I noted before, I believe the problem to be crud in the engine from sitting so long. The coolant has been changed, new fan blade and new radiator with shroud. The issue has to be lack of coolant flow at low idle. What is the best method for me to flush the motor and restore coolant flow? Thanks.

[JohnG]

Could I suggest to everyone who is seriously monitoring their coolant temperature that they do a calibration of their temp gauge? Find out what temperatures really go with T, E, M and P.

There is not much reason to assume the gauge is accurate after all these years (close to 60!).

a) the voltage regulator on the back of the dash might not be providing proper voltage to the gauges (SimplyConnected has a modern upgrade available)

b) the sending unit might not be grounded properly (resulting in artificially low readings)

c) someone may have fooled with the gauge (it is adjustable).

In any event, it helps to know what the needle positions are actually corresponding to.

You could, for example, remove the sending unit (or dig up an equivalent), hook jumpers to it and immerse in a cup of just boiled water (so 212 ish ). Turn the key on and monitor the temperature with a thermometer or temp gun while jotting down needle position. End of mystery.

On the subject of fans, there is some literature out there on the effect of the location of the fan relative to the rear of the radiator. The spacing can make a difference. I vaguely recall years ago it being on some baby Bird oriented site (55-7). If yours is off, you can experiment with a different spacer - - small job, easy to swap back if negative results.

Small detail: having the lowest possible idle RPM can help in traffic simply by reducing the heat being generated.

All else fails, do like Gary Busey in the Gumball Rally: turn on the heat and crank up the blower, comfort be ****ed!

John

[simplyconnected]

Could I suggest to everyone who is seriously monitoring their coolant temperature that they do a calibration of their temp gauge? Find out what temperatures really go with T, E, M and P.

There is not much reason to assume the gauge is accurate after all these years (close to 60!).

a) the voltage regulator on the back of the dash might not be providing proper voltage to the gauges (SimplyConnected has a modern upgrade available)

b) the sending unit might not be grounded properly (resulting in artificially low readings)

c) someone may have fooled with the gauge (it is adjustable).

In any event, it helps to know what the needle positions are actually corresponding to.

You could, for example, remove the sending unit (or dig up an equivalent), hook jumpers to it and immerse in a cup of just boiled water (so 212 ish ). Turn the key on and monitor the temperature with a thermometer or temp gun while jotting down needle position. End of mystery.

On the subject of fans, there is some literature out there on the effect of the location of the fan relative to the rear of the radiator. The spacing can make a difference. I vaguely recall years ago it being on some baby Bird oriented site (55-7). If yours is off, you can experiment with a different spacer - - small job, easy to swap back if negative results.

Small detail: having the lowest possible idle RPM can help in traffic simply by reducing the heat being generated.

All else fails, do like Gary Busey in the Gumball Rally: turn on the heat and crank up the blower, comfort be d@mned!

John

All of JohnG's suggestions are like gold.
The Constant Voltage Regulator works like a turn signal unit, turning 12-volts on and off. After getting old, the contacts inside pit, carbon, sometimes they stick, etc. More importantly, the frequency gets erratic. The idea is to simulate six volts by turning on and off half the time. Remember, every time the key is on, the CVR is working. So, unlike a turn signal unit, this thing sees far more service over 60 years. The frequency can be checked with a Fluke Meter. Most old CVR's average frequencies are all over the map as they speed up then slow down. Ambient temperature affects them too.

A good engine and body ground is essential.

Four-row cores RESTRICT air trying to flow through them. So, that's why Ford didn't supply them.

Lower idle speeds also means the water pump isn't going very fast and neither is the fan. Today's technology remedied this by using an ELECTRIC water pump and an electric fan. Now, a car can sit running at 400-rpm all day long as long as the alternator is large enough to overcome the battery drain.

Mechanical fans turn too slow at idle speeds, and too fast at highway speeds. Usually at idle speed, the car isn't moving so there is no 'wind' to help pass air through the radiator. At highway speeds, there's LOTS of wind so 3,000-RPM fan speeds only eat more gas. Here in our Northern Winters, big trucks block most of the air going through their radiators. - Dave

[Tbird1044]

A while back, someone tried to associate temperatures with the T E M P indicators on our gauge. Here is what they came up with (see pic below).
I do like the idea of removing the sending unit, putting it in hot water so you know what the temperature really is, and then check the gauge. That removes a lot of variables for your particular application.
Nyles

[Carolina Tee Bird]

need to flush

Is there a better product on the market other than Prestone for a thorough flush. Anyone hear of using CLR? Something is causing slow circulation.

[Tbird1044]

Back in the day when cooling system flushes were more common, shops had a tool that would pump fresh water through the block and then used air pressure to really force/purge the water through the block to flush it. Haven't seen one in years, but they are probably still around. Trying to get sediment out of the bottom of a block can be challenging. A good cleaner and a lot of flushing is probably your best bet.
Nyles