Hot Running Windsor based 427 FFR Roadster

[rhunt]

Just completed my FFR build with Ford Racing 427 Windsor. 6.5 miles on the odometer. All components are new. Std AFCO aluminum radiator with home built shroud and Spall fan. Puller fan. 160 deg F thermostat currently used, but have also tried no thermostat. No difference to max oil & water temps. Ford std. water pump with OD pulley. Used original Smiths electric water & oil temp gauges & sending units from my racing MG. Manifold location for water temp & oil pan location for oil temp. 50/50 water glycol with 2 cans of H2O Wetter. Ambient temps now 65 deg F in TX, water temp hits 210 deg F & oil temps hits 215-200 deg. Laser shot of radiator show about 180 deg F. All air burped out of system, 10 quarts of oil in engine, oil cooler and filter. This is way too hot for my liking especially when summer temps here will hit 95 to 100 deg F. Could both sending units be bad? Any opinions are appreciated.

[TheExtreme]

Check the bottom radiator hose to make sure it is not closing off. I learned when I was young that if water pump, thermostat etc is working well then if it is getting hot running down the road, you don't have enough radiator. If it is getting hot in traffic, you don't have enough fan.

[jhv48]

First, make sure your timing is spot on. Retarded timing will raise temps.
Thermostat should be a 180 degree thermostat. Not the problem here.

Sounds like Air is still in the system. If the water temp climbs to 210 degrees and sits there, there's a pocket of air sitting around your sensor and the water is turning to steam. Do a search on getting rid of the air in your cooling system and follow it.

[DanEC]

Originally Posted by jhv48

First, make sure your timing is spot on. Retarded timing will raise temps.

I don't think 210 is anything to get too anxious about but I second checking your timing. I suspect you may not be running a vacuum advance unit as that seems to be pretty common with a lot of Cobra motors. If not, then initial timing could be very critical to your engine keeping it's cool. If not running vacuum advance the distributor needs to have the centrifugal advance limited so somewhere around 15 to 18 degrees initial timing can be run.

If you are running vacuum advance it should be hooked up to manifold vacuum and not a ported vacuum outlet. My 66 Corvette was set up by GM for ported vacuum advance but by just switching it to manifold vacuum I dropped the engine operating temperature significantly.

[TButtrick]

Can you snap a picture of your Tstat housing to Filler to Radiator setup and post? Picture might get you further down the road to a solution more quickly. The filler has an important dimension between the top mating surface and the bottom pressure relief seal surface. If it aint right, you could be sucking in air while you're driving instead of your reserve coolant at rest. There's been some sound advice given here so tell us what you've done so far. Small blocks and Windsors are notorious for needing a good burp. Does your temp spike and go back to Tstat temp a few times up and down during the first few miles or does it steadily rise and stay there no matter?

At only 6.5 miles, your gonna run a little hot during break-in as the engine is working harder than it ever will when mating surfaces get acquainted. What oil are using for break-in?

[DWRAT]

Is your water pump rotating the correct direction???

[Dwight]

sometime you have to burp the system four or five times to get all the air out.

Dwight

[Dwight]

I would suggest 75% distilled water and 25% glycol. We store our Cobras inside and don't drive them in cool / cold weather so you don't need to low temp protection of the 50/50 glycol. Water is better coolant that glycol. Water wetter is a waste of money in my opinion. Tried it and could not measure any decrease in temperature as advertised.

Dwight

[Dwight]

Ditto on what jhv48 posted.

Use standard pulleys. Better at idle and high rpms.

You posted OD pulleys. Over drive?

Also new motor may be a little tight. Put some miles on it and watch the water temp. Keep it under 240 or so. You will be ok.

Make sure oil sensor is near the bottom of the oil pan to keep it under the hot oil. I like to put my oil sensor in the remote oil filter. They make one that has two in and two out ports. I plug one and install the sensor in the other. Works better and give you a truer temperature.
I have found gauges off 8 to 12 degrees. So don't trust the gauge. Buy a Digital Infrared Thermometers. Cost $35 to $220. I get by with the $140 unit. I bought a couple of $40 to $80 units that were junk.

Longacre Dual Function Infrared Pyrometers 50620 - Free Shipping on Orders Over $99 at Summit Racing

Dwight

[elmariachi]

Don't discount that 160 t-stat being a contributor. Most HP V-8s run at 185-200 normal operating temp. So your 160 thermostat opens once as the car heats up, and never closes again. That's not what you want. If it isn't cycling open and closed over and over then the water isn't staying in the radiator long enough to get that 35-40 degree drop, its just racing through. Car then overheats and stays that way. You need a 180-190 t-stat so that you can create the "heat exchange" properties between the engine and radiator up near the proper operating temp. A weak fan or poorly constructed shrouding can cause this too. Home Depot sells a Bosch handheld infrared temp gun for $40 that will help you nail this problem down in about 10 minutes. Start by measuring the difference between the top hose entry and the bottom exit.

[mikeinatlanta]

One day I'm going to do a thorough test and disprove once and for all the myth of no tstat causing overheating due to excess flow through the radiator. Last one was proving air was in fact not hotter closer to the track surface.

Keep in mind that radiator sizing is determined by its ability to exchange heat with the air, not the water. Also this is a recirculating system so single pass heat transfer is irrelevant.

Water/metal contact is an efficient heat transfer mechanism while air/water is not, therefore, the radiator is sized based on air heat transfer. For the theory to be correct, it would require the water to pass the radiator so quickly that it couldn't heat the metal within it, which is simply not possible as a moving fluid is more effective at heat transfer than a stationary one. The air passing a radiator simply doesn't care how hot the water is or how fast it is moving, it only cares about the temperature differential between the air and metal. The truth is that the higher the water flow within a radiator, the greater the surface area of the radiator with higher temps and the more effective it is at exchanging heat with the air. Remember, the purpose of the radiator is not to have low temps at the outlet, it is to exchange heat with the air.

Think about it. If moving too fast through a heat exchanger was a detriment to heat transfer, then going too fast would have the same effect due to excess airflow and cars would overheat at high speed. While there isn't a reasonable purpose to running no thermostat on a car, the reality is that it causes overheating is an old wives tale. It's based on anecdotal reasoning from troubleshooting overheating cars with a little confusion regarding single pass heat exchangers vs recirculating systems.

As for the OP's problem: My money is on either the incorrect water pump or that it is using an inline filler in the upper radiator hose to tie into a coolant recovery system. Tying coolant recovery into inline fillers in the upper hose provides poor air removal due to lacking sufficient space for a stable air pocket to form while water is flowing.

[rhunt]

Mikeinatlanta, thanks. Agreed on the thermostat and velocity of water through the radiator. It is not the thermostat or in my testing cases the lack thereof. There has been no change in the max. water and oil temperatures with three different or no thermostat conditions. In fact I am now an expert on replacing Ford thermostats I've done it so many times. Water pump for the record is correct from Ford Racing for this engine. Although I have put an overdrive pulley on it to turn it faster. Thought I might be cavitating the pump by doing this with no thermostat installed as the pump is centrifugal and operating well out on its curve. Those were my thoughts. This engine ran on the Ford engine dyno without the high temps and put out 537 hp. Will check timing again and some of the other suggestions and then advise all. Inline filler is high on the outlet hose between block and radiator inlet. Have burped this thing more times than I like to count. I do lose a small mount of fluid into the overfill tank after each test run on the car. So I top it off.

[mikeinatlanta]

Originally Posted by rhunt

Mikeinatlanta, thanks. Agreed on the thermostat and velocity of water through the radiator. It is not the thermostat or in my testing cases the lack thereof. There has been no change in the max. water and oil temperatures with three different or no thermostat conditions. In fact I am now an expert on replacing Ford thermostats I've done it so many times. Water pump for the record is correct from Ford Racing for this engine. Although I have put an overdrive pulley on it to turn it faster. Thought I might be cavitating the pump by doing this with no thermostat installed as the pump is centrifugal and operating well out on its curve. Those were my thoughts. This engine ran on the Ford engine dyno without the high temps and put out 537 hp. Will check timing again and some of the other suggestions and then advise all. Inline filler is high on the outlet hose between block and radiator inlet. Have burped this thing more times than I like to count. I do lose a small mount of fluid into the overfill tank after each test run on the car. So I top it off.

If you have an inline filler with coolant recovery tapping off of it, I'm betting you still have a bunch of air. Coolant recovery can't remove air unless there is a stable air pocket at removal point. With an inline filler, you tend to only get a bit of air removal at the point that the system is pressurizing but the tstat is still closed and stopping flow past the filler. It will eventually get the air out, but it will be a slow process taking many cycles.

I suggest that you look at a cobra earl's chevy tstat adaptor and a tall chevy filler. It allows a nice air pocket at the top of the system and will turn burping into an easy task. Alternatively, abandon coolant recovery and install a surge tank system.

Here is the CobraEarl's adaptor.


Here is the tall chevy filler that would go on top of it. It gives a nice air pocket at the top of your system for coolant recovery.

[elmariachi]

Originally Posted by mikeinatlanta

Think about it. If moving too fast through a heat exchanger was a detriment to heat transfer, then going too fast would have the same effect due to excess airflow and cars would overheat at high speed. While there isn't a reasonable purpose to running no thermostat on a car, the reality is that it causes overheating is an old wives tale. It's based on anecdotal reasoning from troubleshooting overheating cars with a little confusion regarding single pass heat exchangers vs recirculating systems.

You are wrong, but you are certainly entitled to your "opinion." A properly constructed heat exchange system with the right thermostat will offset and resolve any notion that higher speeds would in turn escalate heat. That's why it's a heat exchanger. You can call it old wives tales but it takes two of my hands to count how many times I have helped people with overheating engines in cars that operate in the street and the problem was either the wrong thermostat or one missing and nothing else.

I am not here to predict the OP's problem and look smart and cool. My posts generally offer advice based on my experiences. It would appear the OP has ruled out the thermostat anyway.

[mikeinatlanta]

Originally Posted by elmariachi;

I am not here to predict the OP's problem and look smart and cool.

No need to make it personal. I'm absolutely fine with you being misinformed, just trying to help keep the OP from following in your footsteps.

BTW: Looks like the Stewart Components agrees with my claim, however, no doubt that the misconception that you subscribe to is the prevalent train of thought, no matter how illogical or impossible it may be.

Clip from the Stewart article posted by cycleguy55:

"A common misconception is that if coolant flows too quickly through the system, that it will not have time to cool properly. However, the
cooling system is a closed loop, so if you are keeping the coolant in the radiator longer to allow it to cool, you are also allowing it to stay in
the engine longer, which increases coolant temperatures. Coolant in the engine will actually boil away from critical heat areas within the
cooling system if not forced through the cooling system at a sufficiently high velocity. This situation is a common cause of so-called "hot
spots", which can lead to failures."

EDIT: Don't want to sidetrack the OPs thread, however, I would challenge anyone to provide a single shred of scientific evidence that increasing coolant flow (by removing the thermostat) in a close system will lead to loss of the heat exchanger's ability to function.

[jhv48]

I always thought that the original purpose of the thermostat was to recycle warm water through the engine so that it would reach optimal operating temperature quicker. Once that temp was reached, the thermostat would slowly open to increase flow through the radiator to maintain that temp.

Therefore, eliminating the thermostat would only cause the engine to take longer to reach its normal operating temperature.

Is my thinking off?

Now, if you want to solve your problem, jack up the front of your car as high as it will go. Beg borrow or steal a Lisle coolant filler funnel kit. Remove radiator cap, insert funnel, add coolant, start engine and watch the magic. Air bubbles will emerge as your thermostat opens. Once the bubbles stop, turn off engine. Make sure you only put enough coolant in the funnel to cover the tip, as when you shut off the engine, boiling coolant will want to exit your engine and will fill the funnel.
Let cool, then remove funnel and put radiator cap back on. You do have a coolant recovery system in place don't you?

[elmariachi]

Originally Posted by mikeinatlanta

BTW: Looks like the Stewart Components agrees with my claim, however, no doubt that the misconception that you subscribe to is the prevalent train of thought, no matter how illogical or impossible it may be.

Wrong again, suggest you go read the first paragraph of the Stewart article, which is what most people who have been around high performance street cars already know: A thermostat is essential in preventing overheating. What Stewart is saying is that WHEN THE THERMOSTAT NEEDS TO BE OPEN.....a faster flowing passage is what you want (vis-a-vis their hi-flow thermostats.) They are then saying that such faster flow is not a bad thing. You are taking that out of context to suggest that it supports your theory that if a hi-flow thermostat is good, then no thermostat at all is better.

Look, it doesn't take a rocket scientist to understand that the two purposes of a thermostat are: 1. Achieve and maintain under all conditions the "optimal" operating temperature for a given engine (to Madmaxx's post above) and, 2. Regulate/control the flow of water/coolant in order to accommodate conditions (like stop and go driving on the street), where airflow across the radiator and water flow from higher RPMS aren't available to assist in creating the needed heat exchange and dissipation. The absence of a proper heat exchange is going to increase the chances of a healthy car overheating, and guarantee an unhealthy car to overheat. Sorry you can't get your head around this.

I tend to agree with the notion the OD pulley is possibly a contributor given you have ruled out the thermostat. Rhunt...is your engine carbureted....are you sure about your mixture tuning? If its running too lean, even by a little, that will drive temps up and nothing will stop it.

[rhunt]

Thanks. All good suggestions. Will check each out today and advise results. And yes OD = overdrive pulley, so pump is turning faster than stock. For the record, have tried three thermostats and no thermostat as previously stated. The thermostats were 190, 180 and now currently 160. No change to max water & oil temperatures by changing thermostats or with no thermostat. Just a different time rate to reach the max. temp. Also started with 100% H20 before switching to 50/50 H20/glycol for pump lubrication & corrosion reduction reasons. Oil sensor was previously in oil filter adapter on side of block. It is now removed and in pan at middle of oil level. No change in recorded oil temps. based on location.

[Cobrafann]

When you say you have a OD pulley, that means you have a smaller pulley, correct?
Not a larger pulley.

[cycleguy55]

Originally Posted by rhunt

Just completed my FFR build with Ford Racing 427 Windsor. 6.5 miles on the odometer. All components are new. Std AFCO aluminum radiator with home built shroud and Spall fan. Puller fan. 160 deg F thermostat currently used, but have also tried no thermostat. No difference to max oil & water temps. Ford std. water pump with OD pulley. Used original Smiths electric water & oil temp gauges & sending units from my racing MG. Manifold location for water temp & oil pan location for oil temp. 50/50 water glycol with 2 cans of H2O Wetter. Ambient temps now 65 deg F in TX, water temp hits 210 deg F & oil temps hits 215-200 deg. Laser shot of radiator show about 180 deg F. All air burped out of system, 10 quarts of oil in engine, oil cooler and filter. This is way too hot for my liking especially when summer temps here will hit 95 to 100 deg F. Could both sending units be bad? Any opinions are appreciated.

Why are you concerned about 210°F? That's well within normal range and far from overheating or boiling over - unless you're running straight water with no pressure cap.

As others have pointed out, the 160°F thermostat is too low, and a 180° or 190° would be much better. As you have noted, it made no difference on your temperatures.

Check out the tech tips on pages 21-23 of this: https://stewartcomponents.com/wp/wp-...rt_catalog.pdf