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1967 Fastback converting to Electric Fans / Carburetor fuel boiling

Okay here is the scope. I ran it on the highway and it stayed in the low/C area the entire ride (as expected) and around town which I assume is around 170..

I then let idle for about 5 min. Drove it at idle for about 1/2, the let it idle again for about 5 min And it rose just below the halfway mark. And the temp was 215.

Now I normally don’t ever see it that high when I’m driving or even at a stop light because I’m usually not stoped for 8 min.



But is 215 high? And is that temp normal just to be sitting at idle for 5-8 min.


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I've been able to drive my car a fair amount the last week and half or so. Mine is a high compression, stoutly built engine. It makes the heat. I run a 195 thermostat, FlowCooler water pump, a two row aluminum radiator with a single, shrouded electric fan. When driving along in town it will stay right about 202, give or take a couple degrees. In city traffic the worst it gets in stop and go is about 212.

215 is not alarmingly high but the disparity between driving temps and hot idle is quite large and not common. Pretty good sign your cooling system is not exactly delivering the best results. If your accurate about it normally running at 170 in operation that is more of a concern in my mind. That is too cold and your engine can suffer for it. Aside from power loss, you can also be getting greater cylinder wall wear, etc. 190s are a much better temp range for best performance and wear.

If your temp is really rising 45 degrees from highway to idle I would certainly be looking at the fan and radiator as area that needs help. After figuring out that first part, I would pull the thermostat and install a TESTED 195 or so and see how things go. The car should not run any hotter at max temp but it should help to raise your "normal" operating temp to a better range.
 
Okay thanks for the advise. I guess I should not assume the 170. I will driver it normally and set what temp it is when it floats around the C.

I’m curious on your stang, if you driver it around town and let it site at idle for 8 min or so, will it rise above 215.

I don’t run headers or anything, just a simple 351w with performance intake, and mild cam, 650 quickfuel carb.


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I've been stuck in heavy traffic headed out to some local cruise nights lately where I sit on four lane roads (2x2) in traffic lights deep enough it takes a couple cycles to get through, surrounded by cars with nothing but hot exhaust air around me and it goes up only maybe 5-7 degrees which is when it maxes out at my gauge reading of 212ish. I have the FiTech handheld displaying some data points (one of which is coolant temp) and it follows the same path albeit about 15 degrees cooler. Their sensor is known to show cooler. Plus it is mounted in the waterneck and the dash gauge sensor is in the intake crossover so they might read a couple degrees differently anyway.

I still suggest a better gauge but at least use a temp gun to establish what your current stock gauge readings are indicating in an actual temp. I'm hoping that 170 is actually much warmer but it could be that if you have a 165 degree thermostat in the engine. You really need to know what you have there. It'a really easy to pop in a new one so I suggest you do that too.

Lastly, it's normal for it to get hotter sitting idling. Especially in traffic on a still, hot day. As long as the temp doesn't get too hot no harm. What you want to see is the cooling system being able to keep it to a reasonable temp and recover when you get moving again with the added benefit of more volume and also cooler air flowing through the rad.
 
Thanks for the the info. My normal operating temp around town looks like around 205 and it’s about 90 degrees out right now. I then let it sit at idle for 10min with the air on and it hit 230!! Ouch.

This weekend I will see if I can RR the thermostat with a 195 and see what happens.

Just curious does anyone use redline water wetter and does it work?

Question: Does the fuel in the fuel bowls supposed to drain out after a few hours? Or at least not visible in the sight glass? When I park it for the night the next day it looks empty, but normally when it’s cold one pump of the peddle and a few cranks and it’s starts up pretty good when it cold.




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If you do replace the thermostat be sure to look at the old one and see if you can make out what temp it was. Also be sure to test the new one before installing. New ones can fail to open. Lastly, be sure to put it in facing the correct direction. You’d be surprised how many people do it backwards.
 
Thanks for the the info. My normal operating temp around town looks like around 205 and it’s about 90 degrees out right now. I then let it sit at idle for 10min with the air on and it hit 230!! Ouch.

This weekend I will see if I can RR the thermostat with a 195 and see what happens.

Just curious does anyone use redline water wetter and does it work?

Question: Does the fuel in the fuel bowls supposed to drain out after a few hours? Or at least not visible in the sight glass? When I park it for the night the next day it looks empty, but normally when it’s cold one pump of the peddle and a few cranks and it’s starts up pretty good when it cold.




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I use water wetter, I have a big block in my 67 so I tried that to help lower the temp in traffic. My issue is airflow. So the water wetter helps but isn't a "fix"

and the fuel should stay in the carb. Some can boil out but it shouldn't be that much.
 
The Water Wetter discussion can get dicey. There is science behind how it is designed to work but many argue it cannot really do it's thing in a car cooling system because of the high flow and circulation rate of the fluid through the radiator. You can Google the topic and find lots of info. Royal Purple makes a similar additive that has more corrosion protection stuff in it that would seem to make it a better choice, IMHO. Then again, I base that mainly on the fact I have an aluminum radiator and heads. The heads already give a slight advantage in cooling and the added protection seems a positive benefit. Better than a sacrificial anode alone anyway!

For the price of either it seems it couldn't hurt to test it out. Even a couple degrees can make the difference.
 
Terry,
I don't argue the science either way but my experience has been that it is worth a couple degrees. Some tracks don't allow antifreeze because it's hard to clean up if it leaks on the track. I used it for the potential drop it temp (mainly while sitting in traffic). My car has never overheated since I have had two fans but still gets hotter than I like in traffic. But like I mentioned before, it's not a fix, just maybe a helper.
I did buy the Royal Purple stuff this time when I put the engine back in.
 
I'm with you Craig. I've used Water Wetter in the past and will be putting the new Purple stuff in after my first system flush which is rapidly approaching as I rack up the miles. You hear guys spewing stuff about 20 degrees cooler and such pretty frequently. I just wanted to pump the brakes a bit was all. The science is real and given a particular engine and cooling system set-up some find it works others don't. But like I said, for about $10-15 it can't hurt and it might just help.
 
did you run 15% antifreeze like the Redline Water Wetter recommended? I did. water is a better coolant than antifreeze and the science behind the water wetter makes sense. But I can get away with only 15% down here. Up North maybe not a good idea
 
I will run straight water with the Purple stuff during driving season and then maybe add some anti-freeze for winter storage. Not likely but I suppose if we got a really cold stretch I might have freezing concerns in the garage over night. There is enough anti-corrosion stuff in the Royal Purple product that you don't need other protection.

In the past, I ran straight water with the Wetter stuff and recall it made a noticeable difference. Have to wonder though how much of that was attributable to the straight water alone. The "wetters" simply allow more surface contact between water molecules and the metal surface. Given enough time and the right surface, more heat dissipation can occur. That's why the automotive application can be tricky given such high flow rate conditions.
 
Question: Does the fuel in the fuel bowls supposed to drain out after a few hours? Or at least not visible in the sight glass? When I park it for the night the next day it looks empty, but normally when it’s cold one pump of the peddle and a few cranks and it’s starts up pretty good when it cold.
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My garage always smelled like gasoline for as long as the car was driven as a daily driver. We had a detached garage at the time and I wasn't sure if the smell was from the lawn mower or one of the cars. I thought it was the mower.
One time I bench checked overnight to see if the carb was leaking and couldn't detect any. I have rebuilt the carb many times. Its done this for the 49 years I've owned the beast and I just came to consider it normal. But others have brought it to my attention that it is not normal and must have a slow leak in the casting someplace. Now we have an attached garage and the car is driven infrequently and I notice the bowl will go dry in 4-5 days and the smell in the garage goes away. One shop owner told me that fuel should stay in the bowl for months*. Lately I've taken to filling the bowl up before I try to start it or I have to crank it forever. I think its had a slow leak all these years.
*I tested this by filling a glass with as much gas as the bowl would hold and placed a metal plate over the top with a vent hole like the carb. It didn't stink-up the garage and it slowly evaporated over several months- can't remember the number but it convinced me I had a leak, and my car is abby-normal (Young Frankenstein). I intend to go with an EFI system in the future and that should be the end of that problem.
 
I see you have a 195 thermostat, should I do the same. 351w in Florida?



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I see you have a 195 thermostat, should I do the same. 351w in Florida?
People always get confused about the function of the thermostat. It's goal is to get the car up to operating temperature not to set the limit of the coolant/engine temperature. It restricts coolant flow/volume when the temperature is lower than its predetermined value. After that it is the job of the radiator, waterpump and fan to keep things under control in terms of fluid temp. Using a colder rated thermostat will not necessarily keep your engine colder. In fact, it can be argued it can cause it to run hotter by allowing the fluid to flow through sooner and constant which could cause the flow through the radiator to be to great not allowing the time required to displace heat.

It all goes back to having a radiator/fan set-up capable of reducing the heat your engine generates. If your radiator can displace more than is generated the system can function well regardless of your thermostat opening point. Whether in the desert or Canada its all the same really.
 
Interesting i tested the thermostat currently In the stang and it must be 160-165???



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Update: put in the 195: and tested it and it works. Driving it normally it’s sits right a 195.

But when I pulled over and let it sit at idle for 3-5 min the temp started to rise. About 5 min it rose to 230. So I drove it around to slowly cool the motor back down.

I’m assuming it will need an electric fan??


Option 1:

If so do I just get a pusher and place it in front of the evaporator? And keep the mechanical.


Option 2:

Do I remove the mechanical fan and replace it with something like this??

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puller fans work better for flow. Also you need to be careful of how manufacturers rate the CFM. If that's a true 2500CFM that should work great.
 
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