I am finishing up my electrical replacement and Ron Francis recommends a 160 degree thermostat for carbuerated cars (180 degrees for fuel injection). I had read in a few threads here that the consensus seems to be 180 degree thermostat. Is this a concern because the there would be a greater temperature difference across the heads?
I am finishing up getting my 66 302 running but it is overheating after running 5 minutes or so. I put a new 2 row aluminum radiator, new reverse flow water pump with the serpentine kit, 180 degree thermostat. I also run my c4 tranny lines to the radiator. I was thinking about running the car with the radiator cap off so I can see if the coolant moves at 180 degrees. The electric fan is giving me some struggle to get the probe to come on consistently at the right temperature - it is in the bottom above the lower hose. Could timing be an issue? I think I'll check the float levels, maybe it is getting lean after running a bit?
I would run a 180 for carbs and 195 on injected. Reason being that computer cars are set to run at that and you will dump in more fuel at cooler temps. Also, it holds the coolant in the radiator a little longer to cool. I would put the probe near the top of the radiator, isn't it warmer up top?
I run 195 in mine. you should always run as hot as you can without compromising the tune or detonating. Hotter engine = hotter air/fuel charge = more rapid combustion = more power. The thermostat has nothing to do with overheating, unless it's stuck shut. It's a big issue on carb'd cars since cooler temps result in less fuel atomisation and you loose all your carburetion advantages. EFI will get stuck in open loop if it's too cold.
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Who cares how much horsepower it has, all that matters is how fast it goes!
Best run 13.23 at 106.97mph with a 2.183 60' Times from before tune and driver mod.
Not trying to argue but, I have to disagree with that. The thermostat does have something to do with overheating...but, I don't think so in this case. Also if higher temp = more power than, why the cold air induct?
Also, I thought the reverse pump was merely because of the serp belt, it drove it opposite to v-belt. Am I wrong on that?
The thermostat has zilch to do with overheating unless it's not opening or not flowing enough. I run a 195 high-flow and it works great. Temp sits at 200-215 depending on ambient air temp and driving conditions.
Cold air induction provides more dense air (cold air is more dense than hot air), allowing you to in turn provide more fuel, which then makes more power. The engine's temperature is what helps atomize the fuel as it makes its way down the intake runners. Better atomization makes more power.
1) you need to move your temp probe to the top of the radiator it goes right under the hose on the top as that is the hot water exiting the engine and is equal to engine temp. The bottom of the radiator is cold water used to cool the engine.
2) if having your fan come on consistently as it should once 1 is fixed does not solve the problem then you are not running a big enough cooling fan or you are not running a shroud....the shroud directs air flow through the rad not around it.
what fan are you using and is your engine bored out? How much HP are you producing?
-Gun
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Masters of Industrial Technology intelligence that’s why I own guns made to drop elephants.
Thanks guys. Quick question on the temperature probe - if I have a reverse flow water pump, doesn't the coolant enter the bottom of the radiator and go up (that's why I put the probe at the bottom, which in hindsight, I am not sure makes sense - heat rises so the top of the radiator should be hotter but I was thinking in terms of where the coolant entered the radiator).
Gun Jam, I am not sure about the engine - I bought the car and the guy said the engine had been bored .040 over. The car had been sitting for several years and they said it was running great when it got parked. So instead of breaking into it, I just re-torqued the heads and put a Edelbrock intake/Barry Grant carb and thought I would give it a shot......once you start tearing into the motor, it is a slippery slope.
I wonder if the thermostat is working correctly, even though it is new, I think I will take the radiator cap off tonight and let it run to make sure it is flowing.
Also, can someone confirm that the direction of the coolant in a reverse flow system enters the radiator at the bottom?
Additional info - I have a psyclone electric fan - 2500 cfm (this seems pretty turbo, when it is running, it pumps some air). It does not have a shroud but it covers most of the radiator and of course is attached to the radiator.
I am wondering if I seated the distributor in correctly - I put in a Mallory HEI distributor and wonder if I have the teeth off? The car seems to sputter a bit if I push the accelerator quickly to floor, this could be float level too I reckon.
I have been working on this car and tore everything down to the shell and rebuilt it back up over the past 2 years. Now that we finally have it started, I am dying to get it on the road so this is really frustrating. The JBA header back exhaust sounds awesome and I can't wait to get this bad boy rolling
Reverse flow water pumps still flow in the same direction(they're actually reverse rotation water pumps), coolant exits the top of the engine and enters the top of the radiator. Some newer engines have flow entering the top to cool the heads more effectively. On SBF's the reverse flow water pump has a "backwards" impellar in it, this means that it pumps effectively when the water pump is rotating in the opposite direction. This is for the late model setups that wind the serp belt around other accessories such that the back side of the belt runs the water pump, turning it in the opposite direction. If you have a reverse flow water pump and are turning it in the standard direction, that will cause overheating since the pump's impellar can't move the coolant properly.
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Who cares how much horsepower it has, all that matters is how fast it goes!
Best run 13.23 at 106.97mph with a 2.183 60' Times from before tune and driver mod.
Here is a picture of the top of my water pump. So if I am reading you correctly, the water on the reverse flow water pump still exits the top of the engine and into the top of the radiator? Definitely going to relocate the probe tonight and take off the radiator cap to make sure I am getting flow as well (and it was a pain to get in there.....).
I might have to boot up to the "ice box" Ron Francis sensor that has a metal ring that screws underneath the water pump bolt to get an accurate reading, hate to spend the $114 but that might be cheap if I blow the engine or do other heat damage.
Based on feedback below, I am staying with the 180 degree thermostat (think I will send an email to Ron and ask for clarity)?
houston, we have a problem. I took the cap off but when the car heated up to the point where the thermostat might open, the coolant start to just come out the top instead of flowing across the radiator below - does this mean I might have a blockage? The car sat for several years and the coolant pathways were rusty when I looked inside but I didn't think it would be blocked (I had put some rust neutralizer in the coolant and was going to run it a few weeks and then flush it to get some of the rust/scale off).
Any ideas? I am thinking to drain some coolant and then take the thermostat out just to make sure that there is flow. It is getting a bit frustrating trying to resurrect this old pony, but I am on a mission
I doubt the block passages are totally obstructed. Im not sure what to tell you except to check the lower hose to makes sure its not collapsed. How bout that thermostat which direction did you install it?
-Gun
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Masters of Industrial Technology intelligence that’s why I own guns made to drop elephants.
I am wondering if I seated the distributor in correctly - I put in a Mallory HEI distributor and wonder if I have the teeth off? The car seems to sputter a bit if I push the accelerator quickly to floor, this could be float level too I reckon.
...have you retimed it? Retarded timing is a surefire way to overheat an engine, and can also cause that hesitation.
Once it starts to warm up, the radiator will overflow without a cap. The cap is there because the heat builds pressure, and if it's not contained it will change volume(spill out the open cap). Check your timing first.
_____________________________
Who cares how much horsepower it has, all that matters is how fast it goes!
Best run 13.23 at 106.97mph with a 2.183 60' Times from before tune and driver mod.
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thermostat recomendation/overheating - 
