Cooling system questions
Thread Starter
Racer
Joined: May 2016
Posts: 492
Likes: 35
From: Norwalk, Ct
Cooling system questions
Hey guys,
I have a new to me 69 427 tripower that I am trying to sort and get a feel for. I took it out for 20 minute ride and noticed the temp get up to 210° so I stopped and let it cool down and got her home.
The previous owner put in a Champion radiator, high flow water pump,electric fans and a c4 vette coolant sensor to activate the fan around 200°. I swapped the surge tank cap to a 13lb unit and replace the thermostat with a 195° unit. The question I have is while the car is running the upper rad hose and heater hoses heat up quicker than the lower hose does and after a few minutes of idling the system seems to build pressure.
I ultimately want to get a Dewitts direct fit rad and go back to the factory set up but for now does my system seems OK? I am just concerned with the system building pressure so quick and the fact that the lower hose stays cool longer than I think it should.
I have a new to me 69 427 tripower that I am trying to sort and get a feel for. I took it out for 20 minute ride and noticed the temp get up to 210° so I stopped and let it cool down and got her home.
The previous owner put in a Champion radiator, high flow water pump,electric fans and a c4 vette coolant sensor to activate the fan around 200°. I swapped the surge tank cap to a 13lb unit and replace the thermostat with a 195° unit. The question I have is while the car is running the upper rad hose and heater hoses heat up quicker than the lower hose does and after a few minutes of idling the system seems to build pressure.
I ultimately want to get a Dewitts direct fit rad and go back to the factory set up but for now does my system seems OK? I am just concerned with the system building pressure so quick and the fact that the lower hose stays cool longer than I think it should.
Thread Starter
Racer
Joined: May 2016
Posts: 492
Likes: 35
From: Norwalk, Ct
I think it was a 195°, previous owner installed it.I though a 195 was the factory replacement for this engine,, could this radiator be cooling so much better that the lower rad hose heats up before the upper and heater hoses?, also the fan that was given to me with the car was a 7 blade is that correct for a 427/400 with a/c and 4 speed?
Thread Starter
Racer
Joined: May 2016
Posts: 492
Likes: 35
From: Norwalk, Ct
Currently it has a Champion radiator with their dual fan/should set up.and I wouldn't say it's over heating but it got up to 210 on the temp guage. I just want to make to make sure everything ok as you know these cars are older and you never know what has been done to them over the years.
Race Director
Joined: May 2006
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Again, not sure why you installed a 195, it should have been 180.
The 195 only Starts To Open at 195 so 210 is normal for that thermostat.
Also not clear why you changed surge tank cap to 13, you didnt mention what the previous one was, should be a 15.
The 195 only Starts To Open at 195 so 210 is normal for that thermostat.
Also not clear why you changed surge tank cap to 13, you didnt mention what the previous one was, should be a 15.
Last edited by MelWff; May 8, 2021 at 02:54 PM.
Race Director
Joined: Mar 2017
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From: Virginia
For real peace of mind, pick up an infrared thermometer. Use it to see what your actual temperatures are. You should see a difference between the upper and lower radiator hoses. Don't trust the stock gauges, except to see if there's a change.
Also, what is your timing set to? Retarded timing (and for our cars, that means factory spec timing) will also lead to higher operating temperatures.
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1967 Pedal Car Champion
Joined: Mar 2020
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Likes: 4,177
From: US-PNW
So the 195°F thermostat doesn't even open and allow cooling until that temp, so it's never going to run cooler than that. 180° is the better choice, even 160°. I think your cooler lower hose is indicative of a closed thermostat that isn't allowing circulation.
Post a few pics of the forward 1/2 of the engine and the radiator area from both sides of the car - you may be missing components that aid in cooling.
Post a few pics of the forward 1/2 of the engine and the radiator area from both sides of the car - you may be missing components that aid in cooling.
Had a 1976 L-82, 4-sp
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From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
It looks like it didn't work, if you are posting here and second guessing yourself.
For real peace of mind, pick up an infrared thermometer. Use it to see what your actual temperatures are. You should see a difference between the upper and lower radiator hoses. Don't trust the stock gauges, except to see if there's a change.
Also, what is your timing set to? Retarded timing (and for our cars, that means factory spec timing) will also lead to higher operating temperatures.
For real peace of mind, pick up an infrared thermometer. Use it to see what your actual temperatures are. You should see a difference between the upper and lower radiator hoses. Don't trust the stock gauges, except to see if there's a change.
Also, what is your timing set to? Retarded timing (and for our cars, that means factory spec timing) will also lead to higher operating temperatures.
Race Director
Joined: May 2006
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Running a 195 thermostat with a sensor designed to turn the fan on at 200 is an excellent way to have the fan constantly running and prematurely burning out.
This is the type of thermostat you need.
Last edited by MelWff; May 8, 2021 at 06:56 PM.
Thread Starter
Racer
Joined: May 2016
Posts: 492
Likes: 35
From: Norwalk, Ct
Thanks for all the comments guys, as stated before I bought the modified with a larger cam in it and come to think of it the previous owner put in an Hei distributor and disconnected the vacuum advance. He stated that he changed the spring for the weights in the distributor.
One of the things I want to do is swap the distributor to possibly an Msd but try and make the car as stock appearing as possible. There is also a Holley 850 carb on the car that to me seems to be running rich because after a minute or so of running my eyes start to burn like crazy. So in conclusion I think I may have a few things going on but I will post pics tomorrow and try you suggestions.
One of the things I want to do is swap the distributor to possibly an Msd but try and make the car as stock appearing as possible. There is also a Holley 850 carb on the car that to me seems to be running rich because after a minute or so of running my eyes start to burn like crazy. So in conclusion I think I may have a few things going on but I will post pics tomorrow and try you suggestions.
Race Director
Joined: Mar 2017
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From: Virginia
Not singling you out because I see this all the time. Yes, the engine temps will increase but that's where the cooling system removes the extra heat to prevent the engine from overheating. Most C3's came with smog equipment and retarded timing but the cooling systems were designed to handle this. To think otherwise would mean GM engineers forgot to take this into account. I don't think so!
Thanks for all the comments guys, as stated before I bought the modified with a larger cam in it and come to think of it the previous owner put in an Hei distributor and disconnected the vacuum advance. He stated that he changed the spring for the weights in the distributor.
One of the things I want to do is swap the distributor to possibly an Msd but try and make the car as stock appearing as possible. There is also a Holley 850 carb on the car that to me seems to be running rich because after a minute or so of running my eyes start to burn like crazy. So in conclusion I think I may have a few things going on but I will post pics tomorrow and try you suggestions.
One of the things I want to do is swap the distributor to possibly an Msd but try and make the car as stock appearing as possible. There is also a Holley 850 carb on the car that to me seems to be running rich because after a minute or so of running my eyes start to burn like crazy. So in conclusion I think I may have a few things going on but I will post pics tomorrow and try you suggestions.
Please post some photos, including of the carb and dist with the air cleaner removed! I use a similar 180 degree thermostat to what @MelWff linked (a Milodon high-flow). But it's important to have some data!
Race Director
Joined: May 2006
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Is the vacuum advance unit still on the distributor?
If it is, have you tried connecting it to a constant vacuum source?
Are you basing your original post's statement about being a tripower based upon the engine code?
What intake is the 850 sitting on?
If it is, have you tried connecting it to a constant vacuum source?
Are you basing your original post's statement about being a tripower based upon the engine code?
What intake is the 850 sitting on?
Thread Starter
Racer
Joined: May 2016
Posts: 492
Likes: 35
From: Norwalk, Ct
I will get you all some pics tomorrow but yes the advance is still on the distributor and the intake is supposed to be an original Winters intake manifold.
1967 Pedal Car Champion
Joined: Mar 2020
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From: US-PNW
Well, you can't mount a 4-barrel on a tri-power intake... The tri-power has three mounting bosses for the 3 two-barrel carbs... so something is amiss. A Winters intake has a snowflake logo cast into it. They did make single 4-barrel intakes as well.
What is the engine code stamped onto the pad on the passenger, front of the block?
What is the engine code stamped onto the pad on the passenger, front of the block?
Thread Starter
Racer
Joined: May 2016
Posts: 492
Likes: 35
From: Norwalk, Ct
Well, you can't mount a 4-barrel on a tri-power intake... The tri-power has three mounting bosses for the 3 two-barrel carbs... so something is amiss. A Winters intake has a snowflake logo cast into it. They did make single 4-barrel intakes as well.
What is the engine code stamped onto the pad on the passenger, front of the block?
What is the engine code stamped onto the pad on the passenger, front of the block?
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
Your main problems are: You should have a 180*F thermostat in the intake manifold; there is nothing connected to the vacuum advance can on the distributor (this should be connected to MANIFOLD vacuum...not ported or timed vacuum); the high-flow pump is just generating more heat by trying to force more fluid than necessary thru the [higher capacity] aluminum radiator; the electric fan switch should be set to around 190*F {after you install a 180*F stat in the engine}.
You also want to verify that the lower air dam is installed under the nose. It forces airflow up and thru the valence holes and into the radiator when driving.
You also want to verify that the lower air dam is installed under the nose. It forces airflow up and thru the valence holes and into the radiator when driving.