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Discussion Starter · #1 ·
Well I finally got my engine finished. (its been out for almost a year) I started it up for the first time and ran it up to about 1800 rpms to run the cam in. About 10 minutes into the run the temp gauge was starting to get a little on the hot side so I shut it down and looked everything over. There was plenty of antifreeze/water in it and the fan and everything was working properly. I figured it was a bad tstat so I pulled it and started it back up. I finished running the cam in and shut it down and again it was pretty hot. I checked the thermostat in a pot of boiling water and the water got up to 215 and it never opened. It was a 180 degree thermostat. I let it cool and started it again and checked the timing and got it set at 12 degrees intial and got the idle down to about 900 rpms sitting in park. Went and took it for a little spin and it heated right up again, with no thermostat. I am not sure what the issue is. I tried burping the cooling system and it does not seem to have any air in it, tried backing the timing off and that did not help, messed with the mixture screws on the carb and also nothing. I also only have 10 inches of vacuum at idle off the manifold? It has edelbrock e street heads a performer intake hooker super comp headers 1.75 inc primaries, and is running about 10 to 1 compression the cam is a comp cams extreme energy 274 h. I am not sure if that is big enough to cause the vacuum to be that low or not. Any suggestions would be greatly appreciated. I really do not want to burn up my brand new engine. On a positive note it seems to pull very strong and only has about 10 miles on it!!!!:devil:
 

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Get a new T-stat cause without one the water won't have time to cool and pass the heat as it should. Start there and get the cooling part done. As far as vacum goes one of the good engine guys on here can tell you if there's a problem and how to seek it out:thumbsup:
 

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Curious here, does the boiling water test work for sure? b/c I always thought that it only opened under the pressure of the water pump even at temp. So in water that wasn't moving wouldn't it still be shut? Honest question, not being a wise crack or anything.

Also, are those failsafe t-stats that get hung open instead of closed with an overheat or failure worth a dang?

~wd-40:buhbye:
 

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Curious here, does the boiling water test work for sure? b/c I always thought that it only opened under the pressure of the water pump even at temp. So in water that wasn't moving wouldn't it still be shut? Honest question, not being a wise crack or anything.

~wd-40:buhbye:
On a regular thermostat, the part of the thermostat that opens actually moves against the coolant flow, so the answer is that they don't need flow to open.
 

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Discussion Starter · #6 ·
Just thinking here but this be a bad reading because of a grounding issue? I pit the sending unit in the port on the drivers side head and used teflon tape on it. The ground wire for the engine is on the passenger side motor mount. Also with aluminum heads could they possibly be causing a grounding issue the teflon tape between the head and the sending unit?
 

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As two guys above have said, get the T-Stat situation squared away first. If putting a new working thermostat in doesn't do the trick, it could be a timing issue. You didn't say much about how the ignition is set, other than the 12 degrees initial. You want the mechanical advance all in by 2800rpm, with a total of about 36. If you don't have the vacuum advance set up, you should, as it helps throttle response, mileage and engine temperature while cruising.

Retarding the timing below the optimium for a given engine combination starts the combustion process late and the maximum amount of energy from the burning process doesn't go to pushing the piston down the cylinder. The excess energy, in the form of heat, goes into the cooling system and you see the coolant temperature go up.

In a drag engine, the throttle is wide open during most of the pass, so you'd have no vacuum to run a vacuum advance, even if you had one hooked up. A dedicated race engine doesn't have provisions for vacuum advance, so it came about that "only sissies run vacuum advance". For a street engine, the phrase should be changed to "Smart people run vacuum advance".
 

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Discussion Starter · #8 ·
O haven't got the timing all set yet. O set the initial and that was it. The distributor still has both heavy springs and the vacuum advance is hooked up to a timed port. Not sure how much total advance I have but I am sure its not all in until probably around 3200 just guessing with the heavier springs.
 

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O haven't got the timing all set yet. O set the initial and that was it. The distributor still has both heavy springs and the vacuum advance is hooked up to a timed port. Not sure how much total advance I have but I am sure its not all in until probably around 3200 just guessing with the heavier springs.
You want the vacuum advance on a full manifold vacuum port (below the throttle blades), not a timed port.
 

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You cannot run without a T stat on an electric cooling fan system.. Because the sensor to turn the fan on happens at about 232 degreesF:cheers: . Without a stat the coolant never gets hot enough to turn the fan on, and actually causes a overheating problem. Plus the flow of coolant moves thru the engine so fast Is will not cool. Also remember that for every pound of pressure your cap has, you raise the boiling point 4 degrees:cheers:
 

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Discussion Starter · #11 ·
Ok I am going to install a new 180 degree stat and see what happens if it still reads hot on the gauge I will verify the temp somehow maybe I should get a temp gauge and install it somewhere? That way I can see what it actually is in a certain spot. It is not an electric fan set up but a clutch fan. Has anyone ever had a brand new water pump that doesn't pump enough it is an aluminum edelbrock one. If this doesn't do it I will pull the radiator and get it cleaned.
 

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Discussion Starter · #12 ·
Well I put in a new thermostat and fired it up and within about 5 minutes just idling it was pushing 200 degrees. I am beginning to think that the water pump either isn't pumping or the hose to the pump or maybe plugged up of something. This is making me real nervous. Could there be something else causing it besides the cooling system?
 

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I have the same problem!

I had the engine built the engine builder didn't flush it out, I assumed he did. It was running as hot as yours after 5 minutes at idle, I thought maybe just a hot engine but couldnt justify the temp as I have a new huge be cool aluminum radiator with the twin thermo fans setup, I started with the easy stuff like the others have suggested.

I never use the air con so I removed it and the condenser and added another 13 fan to the front of the radiator to blow through and changed the stat from 180 to 160 - this helped about 10* .

But when I drove the car it continued to climb quickly and was freaking me out sitting on 220

We used an infra red tester to check the water flow and temp into and out of the radiator and the temp out was way high.

I decided to pull the radiator and have it checked which on this type of radiator is a real pita, side tank cut off 9 cores blocked !
Was able to access and clear 7 - was full of **** from the build. Had the tank welded back on, re installed expending problem fixed - not. Running slightly cooler but not where it should. Turns out on a normal radiator having 2 cores blocked is not to bad but due to the flow design not good, now have to replace the radiator.

Try installing an in line top radiator hose filter and see what it collects. I have and I am still getting minute particles.

Sorry for saying so much but ime sure you paid a lot for your engine and you don't want to cook it or glaze the new bores.
I will watch the input as it may assist me also.
Cheers adam
 

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Discussion Starter · #14 ·
yelo76 i feel your pain, i have just the stock radiator and have also taken the a/c compressor off. I was considering buying a new radiator when I was installing the motor but kinda ran out of money and wanted to go drive the damn thing and now this. I am thinking I am going to end up at leas pulling it and taking it to get cleaned. I didnt pull my a/c condenser out but was looking at that last night and think it will probably come out this weekend. It just does not make sense that it warms up so fast. I get it is a new motor and everything is tight but still that is awfully fast to heat up that much. I think I am going to try some of that water wetter stuff also and see if that helps at all. Sorry your car is giving you problems but I feel a little better knowing that I am not alone.
 

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I've put the water wetter in also, it did not help mine.

While trying to get my head around this problem I blew the diff up accidentally, well now I will have the gears I wanted.
That was the beginning of march, it's still off the road so I havnt been able to do anything about the temperature.

I have bought a new Edelbrock water pump and will install that, but have to decide whether I replace the radiator with another be cool or Dewitts ?? Ime leaning towards the be cool because I know how well it fits and looks. I've researched both this time and they seem about equal. I can get either sent over for about $600 compared to having a custom aluminum radiator fabricated locally for $1,500 it's a no brainer.

Have you checked the bottom radiator hose isn't collapsing under pressure ?
Have you used a quality brand of coolant ?
Sort out your timing and check the advance ?
Wire up a temporary temp gauge to make sure it's not your gauge giving a false reading?

Hang in there....I know how frustrated you are.

Only replacing the water pump because it was suggested to me that perhaps the impeller may be damaged....for the cost of another pump versus the engine cost it's cheap I guess this is how I am justifying the cost of another radiator as well.
 

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Running without a thermostat is not going to cause the engine to overheat. I am leaning more towards the rad needing to be cleaned.
 

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You cannot run without a T stat on an electric cooling fan system.. Because the sensor to turn the fan on happens at about 232 degreesF:cheers: . Without a stat the coolant never gets hot enough to turn the fan on, and actually causes a overheating problem. Plus the flow of coolant moves thru the engine so fast Is will not cool. Also remember that for every pound of pressure your cap has, you raise the boiling point 4 degrees:cheers:
Don't know what temp switch you are using, but they are available with different on-off temp settings. Mine turns the fans on @180* and back off @ 170*. Works like a champ:thumbsup:Art
 

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My first inclination is to find out your oil temp.
New motors built tight will have very high oil temps on break in.

Cooling (air flow) water flow! Make sure you put some water wetter in your coolant. Many times the block and heads have solvents and other fluids that haven't washed out.
Water wetter and purple ice use surfactants which basically wash the coolant passages and allow water to actually touch the metal and exchange heat.
Timing
Oil temp.



It does
 

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Discussion Starter · #19 ·
Is there different sending units and is it possible I got the wrong one? Also how do you check the gauge to see if it is reading correctly. I got a temp gauge that screws into the coolant passages on the intake and I am going to try that this weekend.
 

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You can buy fan switches with different temperature ranges from Jegs or Summit Racing. When the water reaches the setpoint, the switch closes and completes the ground for the fan motor(s).:cheers: Art
 
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