I wouldn't say you'd be in any danger, but it surely isn't going to fix your issue.

You have something else that's driving that temperature up.

 

Well, when I was fixing a different issue, I found out my stat housing had come loose. Not sure how long it was like that. Never actually overheated, never had to pull over in a cloud of steam, but I think the loose housing may have contributed to the issue.

 

It will probably overheat as the coolant doesn't spend enough time in the radiator to dissipate the heat. I have an Edelbrock high flow water pump and a Griffin 3" radiator with 1.25" tubes and a Weber IDA manifold on my engine with the original style "Cobra" waterneck which eliminates the thermostat. I initially bought an inline thermostat housing that was supposed to be inline with the upper radiator hose. However due to the pends in the hose I wasn't able to fit it. I wound up placing a restrictor in the lower radiator hose outlet to slow the coolant down and keep it in the radiator longer. The thermostat not only allows the engine to heat up faster but also serves as a restrictor for the flow to A) better absorb engine heat by staying in the motor longer B) keeping the coolant in the radiator long enough to dissipate the heat. I believe even the BOSS 302 motor had a washer style restrictor in the thermostat housing instead of a thermostat.

However if the opposite turns out to be true and your car doesn't heat up then all sorts of sludge may accumulate within the engine that would naturally burn off when operating at the appropriate temperature.

 

"...... I wound up placing a restrictor in the lower radiator hose outlet to slow the coolant down and keep it in the radiator longer. ........"

with all due respect, that strategy does not do anything to keep the engine cooler.

While you are possibly keeping the coolant in the radiator longer, at the same time the engine is not getting replenished with fresh coolant in the same amount that you are "keeping" in the radiator longer. So the engine is heating up more than it would otherwise.

FlowKooler has a write up on their web page somewhere regarding that very theory of yours. And there are numerous articles written by those more highly educated in the physics of fluid dynamics & heat transfer than me, which echo the same argument as FlowKooler.

https://www.flowkoolerwaterpumps.co...m/blogs/cooling-resources/doesnt-coolant-need-more-time-in-the-radiator-to-cool


Z.

 

I have a high flow thermostat and a high flow water pump, that might help you some. I have not ran mine yet on the new build but have used this setup in other cars and was pleased with it and it worked. Also agree that you have something else going on which may be the thermostat you have or the fan.


Running with no thermostat will not allow your engine to reach operating temperature and maintain it. Your engine will run less efficiently until it can reach correct operating temp but you will not be able to maintain the correct temp. Running under temp will increase fuel consumption, carbon build up and sludge formation. Over time, this will have negative effects on your engine life as the oil is not maintained at a constant temperature and the heat cycles you get from stop and go can cause head gasket issues as the heads and block cycle differently. IMO, go over what might be causing the temperature issue and fix it, it is better to have a thermostat! Good luck, Jim

 

I had this same problem with mine. I ran no thermostat, 160º and 180º. It still ran hot and would boil over. I have a 2 row 1" tube aluminum radiator and a flex fan. The one thing that cured it was running a 195º thermostat. I am sure it is because it keeps the coolant in the radiator longer so it will cool more. The temp gauge now goes up about half way and then drops down. I believe this is what Ford used when the cars were new.

 

Ditch the flex fan, get a stock type 7-blade that came on A/C cars with a thermo fan clutch. Make sure you have a shroud as well. 190-195 stat with water wetter. If that doesn’t work you have radiator, water pump or tuning issues. (Timing/fuel mixture)

 

+1 to this, aftermarket flex fans are pretty much complete garbage. They're good at two things - making large amounts of noise and slicing your fingers open (or off)...

 

How Old is your water pump?

 

As long as the thermostat is working properly (opening as it should), it has no affect on the max temp the engine will reach. The sole purpose of the thermostat is to control the minimum operating temp. Engines were designed to run at a certain minimum temp. According to my steam tables at STP, at 220 F the pressure in your system would 2.5 psi. If your system is tight and with no leaks, this should not be a problem.

 

The thermostat as part of a complete well sourced system (package) can affect the high end temperature by keeping the fluid in the radiator long enough to cool it effectively. In that sense it does have an affect on the max temperature;that being true then it controls more than just the low temperature. The thermostat a singular device, if the radiator is not up to the task (too small or wrong design), the thermostat then would do less to impact the max temperature, but if the radiator is capable of cooling the motor then the thermostat will control the high temperature by slowing the flow. Without the interference the flow rate is too high to allow time for heat transfer out of the radiator to the atmosphere.

You are correct that 220 is not a problem as long as the proper cap is used and the radiator itself has no maintenance issues.

 

Keeping the coolant in the radiator longer so it can cool more? Where do people come up with crap like this?

 

That is true, you could do some reading before you say someone’s comment is crap.

 

Griffin Multi-pass



I road race a ‘66 making 570 hp (flywheel), I’m using a two row Griffin multi-pass aluminum radiator and an electric fan. I can run Enduro events on hot summer days and not overheat. A two row aluminum radiator has more surface area than a three row; the multi-pass keeps the fluid in the radiator for a longer period, this combined with a good quality fail open 190 degree thermostat is a package I can guarantee would work on the street with no issues.

If you log onto the Griffin Radiator web site you can essentially build your own radiator by answering a few questions about Make, Model, and HP.

The 220-230 temperature is not awful, but if that’s your temperature when you are not hot dogging it, then you may want to consider a multi-pass aluminum... talk with the guys at Griffin for the straight scoop.

Good luck with it.

 

I road race a ‘66 making 570 hp (flywheel), I’m using a two row Griffin multi-pass aluminum radiator and an electric fan. I can run Enduro events on hot summer days and not overheat. A two row aluminum radiator has more surface area than a three row; the multi-pass keeps the fluid in the radiator for a longer period, this combined with a good quality fail open 190 degree thermostat is a package I can guarantee would work on the street with no issues.

If you log onto the Griffin Radiator web site you can essentially build your own radiator by answering a few questions about Make, Model, and HP.

The 220-230 temperature is not awful, but if that’s your temperature when you are not hot dogging it, then you may want to consider a multi-pass aluminum... talk with the guys at Griffin for the straight scoop.

Good luck with it.

Ah, that’s a $700 radiator... A 3-row copper brass for about $200 should do just fine. It does on mine (only 400hp iron headed 347).

 

"Any danger I'm missing if I don't install a thermostat?" In the short term, not really. Not an ideal thing to do as you may have surmised by now.

In the long term is where it gets fun. When you take the valve covers off for something or another a few oil changes later you will be dismayed by the amount black crud sitting on the heads that didn't use to be there. And if you just drive and ignore oil changes the combination of no thermostat and lack of changed oil means that when you do finally get around to changing the oil, it won't come out of the drain plug. You get to pull the oil pan off and dig the "oil" out of the pan with a spoon. Like black pudding. Been there, done that, still got the spoon. People think lots of things are OK to do because they or their uncle did it for years and it seemed OK. The real deal is that these old iron engines can put up with an extraordinary amount of abuse. The poor car I dug the oil out of ran on for at least another two years that I know about before I lost track of that friend.

 

Allright… I'll keep the thermostat. I'm also a stickler about oil changes. My understanding (limited as it is seeing all the comments above) is that the engine heats the coolant up, the radiator cools it down, and once the coolant reaches 190 degrees the thermostat stays open. The thermostat regulates coolant flow to keep the coolant where it needs to be to "get the job done", i. e., in the engine and in the radiator long enough to maintain operating temperature.
If I remove the stat, it'll screw things up.
Simple enough?

 

".....My understanding (limited as it is seeing all the comments above) is that the engine heats the coolant up, the radiator cools it down, and once the coolant reaches 190 degrees the thermostat stays open....."

the shop manual is your best friend here. According to Fords engineers who wrote it; the stock 190 F degree thermostat BEGINS to open at 188 F to 195 F. It's not even fully open until the coolant temperature is 210 F to 212 F.**

so its continually opening and closing under "normal" circumstances in order to keep the engine coolant above 190 - 195 and hopefully close to 210 - 212. The safe zone is another 15 degrees hotter, around 225. then it's up to the rest of the cooling system to keep the temp under the danger zone which most agree is not until you get close to 230. running at 210 - 220 doesn't hurt the engine in the slightest.



Briefly, the thermostat will get the engine up to operating temperature as FAST as possible. As GypsyR alluded to, this is to keep the oil happy. No matter which oil one prefers, if you don't get it hot as fast as possible, sooner or later, it will get like the oil GypsyR described. That is why having a thermostat makes sense for all street cars.

Z

** quoted verbatim from the '65/'66 Ford shop manual

 

The engine is making a certain amount of heat under whatever conditions are present.

The air flow across the radiator is whatever it is based on the fan type/speed and how fast you are driving.

The amount of air and water flow at any given are really independent of each other. Each changes as engine speed changes and/or fans cycle on or off, etc

Heat exchangers (your radiator) work best at a higher temperature differential (delta T). Faster flow rates will usually yield MORE heat reduction than "holding" water in the radiator longer as the water cools more and the heat transfer becomes less effective. All the while the water in the motor is getting HOTTER. But the motor "wants" a certain temperature hence the thermostat (like a fully mechanical control valve). This also of course helps to get the motor up to that temp more quickly.

It is not an exact science. Obviously there is a large range of flow rates that will work together. Just because you flow water a little slower does not mean you will have a problem as the delta T is still relatively high.

 

I also agree with ditching the flex fan for something that will work better. If you want to stay mechanical get a 6 blade fixed fan and a clutch. A shroud is a necessity with these.


I switched to a BeCool cross flow(tanks on top and bottom so actually it is still a down flow) 3 row radiator and opened up my core support for the 19 inch radiator. I spent quite a bit of time on the core support making it look factory. I just an hour ago got my new 331 running IN the CAR this TIME yehaw, LOL, and it is a bit cool here but my fan now cycles on and off and before with the small 16" fan, even a 3 or 4 row radiator was not enough and once the fan came on it stayed on. I also always had to run an overflow tank because it would puke and it looks like I won't be overflowing this radiator at all.



This is a fundamental. If you make x amount of power you have to run a cooling capacity that fits x and the radiator is a very critical part of that along with the fan's capacity. Doing other things won't ever really fix this problem unless your system has the right capacity but something is not functioning correctly.

 

+1 on getting a different fan.

 

All the bits in your engine are designed to work together at temperature.

Ever notice big trucks up north will restrict airflow to the radiator in the winter?

Your best bet is to run the cooling system the way Ford designed it.

 

While the dynamics of engine cooling are pretty deep, let's keep this really simple here:

1) A stock thermostat is very important both in keeping the car cool, and ensuring that coolant temps are where they need to be

2) With too much cooling (which can often be cause by no thermostat, or a low temp one), your oil will also tend to stay cooler, which prevents volatiles from boiling out, and creating sludge.

3) Any car that spends a lot of time stationary or at low speed with the engine running needs a good shroud.

And just one final note: flex blade fans suck, because they don't move as much air, but they rob about as much power as a fixed blade, and they fail frequently, with blades flying off due to fatigue or poor construction. Clutch fans work pretty good, but electric fans cool best and steal the least power. When a car's not moving, but the engine is running, that's when the fan is needed, blowing the most air. Going down the road, air is forced through the radiator without the fan's help. Usually.

 

Cavitation usually occurs when there is a restriction at the water pump inlet.
The pump is pushing water out faster than it can be pulled in through the inlet. This can cause enough of a vacuum behind the impeller blades that the water briefly vaporizes. Water pumps are great at pumping liquids but horrible at pumping gases. Not to mention the rapid erosion caused by the bubbles.
So, if anything, you want the outlet more restrictive than the inlet. Giving the water pump something to push against. And in a way, the thermostat is that restriction at the outlet.
In a perfect world the system would be balanced and inlet volume would always equal outlet volume.

 

Designs have changed in the last few years but before that I think we all should have noticed that about everything out there had a lower radiator hose notably larger in diameter than the upper. So there's that.

 

Oil doesnt need to get to 212* to dissipate moisture either.

 

Absolutely true.
But it’s even more important for the metal surfaces to be at a warmer temperature so that water vapor, a product of combustion, doesn’t condense into a liquid and fall into the oil.
Which is also a good reason for good crankcase evacuation

 

Temperatures higher than 212 do a lot better at getting rid of water.

 

Cob, the factory gauge doesn't read very accurately. If the car doesn't overheat or act weird, then you're probably good. The gauge will mostly just tell you if it's running in its 'normal range'; it doesn't necessarily indicate the actual temperature of your engine. When the needle doesn't point where it usually does, you know there's a problem. If you're not sure about the thermostat, they're really easy to change out, and not expensive either.

 

Interesting read. Im surprised noone mentioned one of the important functions of a thermostat which is to create a restriction in the system to raise the water pressure which lowers the boiling temp of the colant. If you are determined to remove a thermostat to feed an important superstition in your life, you should replace it with a restrictor plate (speedwar motors etc) or just defeat the thermostat portion of the device and install the restrictor portion to its rightful place.

As for leaving coolant in the radiator longer to cool the cool it more, that’s as controversial as Ginger vs Mary Anne. But putting a restriction in the lower hose will also raise the pressure in the radiator and hoses. Not sure that is advisable in the long run.

My advice is to stop re-engineering a system that has been designed to do the job at hand, and get it to operate as designed correctly. These are well understood systems and this problem has been solved many times. Personally I run a four row copper radiator, Edelbrock water pump and stock thermostat. I can spend an afternoon at Thunderhill at100° All day long then drive home in the same hundred degrees in an hour and a half of bay area stop and go traffic with 400hp.

Get ‘er done...

 

Isn't that the job of the radiator cap?

Sent from my Moto Z (2) using Tapatalk

 

Your water pump should not be able to deliver any pressure in a normal system, as it's not a positive displacement pump. Just an impeller. It delivers flow, and ushers water along, but if that flow is impeded (with a block-off plate) the water can just swirl round and round in the pump without delivering any pressure whatsoever.

The cap itself definitely raises the boiling point, by keeping things under pressure.

 

This one got me searching:

Water Pump Design
The basic belt-driven water pump design in most applications hasn’t changed for many years. Most water pumps are centrifugal designs with cast or stamped metal impellors. But, some designs use molded plastic impellors. The water pump must produce enough volume to cool the engine at idle and also at full speed and power output.
In concert with water pump design, thermostats are designed to slightly restrict coolant flow from the engine. This restriction allows the water pump to build additional pressure in the engine water jackets to further reduce surface boiling on the cylinder heads and to reduce pressure on the radiator header tank at high engine speeds.

 

Dobro, I hadn't even considered that. Our water pumps DO put out a few pounds of pressure at best (at least enough to move coolant upward a couple of vertical inches with a decent volume of flow). At low RPMs, the pressure is pretty negligible. It's pretty easy to just dismiss that small amount of additional force. But even a few PSI is enough to raise the boiling point quite a lot, if the pressure's mostly being contained in the block!

I love these forums. Still learning new stuff almost every day. =)

 

BTW- I didn't mean to say that 'no centrifugal pump makes pressure'. Just pointing out that a typical car water pump does not produce much, and it's not designed to fuss even when there's zero flow - it won't stop the pump from spinning.