JohnEvans = correct. YourevilTwin = incorrect / with all due respect, your logic is not quite right sir. Mech. Engineering Statics professor (w/strong Chinese accent) at General Motors Institute said to my class one day back in 1986 when someone complained about not getting partial credit on a test question, "You build bridge. Bridge fall down! NO PARTIAL CREDIT!!!"
why am i picturing some guy chinese accent saying no partial credit in my head? hey im just stating what i have done and used and it has worked for me. im sure theres folks here that have been doing it longer and know more though so i repectfully step aside and will just read from now on until dude can find out what it is since im curious to know why and what myself.
ive never used pusher fans myself only puller fans controlled with a temp switch or controller. i just mentioned him possibly using one since it seems he wants to use his pulley driven fan he has already. if it was me id use a electric puller fan from the beggining and take more parasitic loss off the drivetrain relieving the waterpump from having to spin that fan.
do you have the correct water pump on it there are right handers and left handers, could be not pushing water enough, if backwards impeller.
I learned this lesson a while ago... Is the sending unit the EXACT ONE that came with the temp gauge, IE: The one that was in the head before the rebuild?
....i think it is air blocked ,i can feel the air bubbles knocking in the upper hose.i throttle up and on the way down i grab the hose...this is at 190 so it is not boiling... ....how do i get the air out ???????
You can feel the air bubbles in the hose? Pull the thermostat, boil check it to see how smooth it works. It probably isn't.
i took it out ...again...i have tried with a 180 a 195 and no stat 3 times each ....i think the block is air bound ??? how can i bleed it out ???thanks
Get a thermo you trust is correct and drill a 1/16" hole in it. I don't see how you could have air trapped in upper hose as it is open to top tank???????????? In extreme cases I have had to jack some SBC auto/trucks up in front to get air out...........
Verify that these thermostats work. As I mentioned before if you are having a problem with air in the head, jack the front of the vehicle as high as you can. I think AutoZone still has the tool loaner program. See if you can get a coolant system pressure tester. Pressurize your system without the engine running and listen for leaks.
i have a pressure tester no leaks intrenal or external i have a block check it test clean..i think the extra fan is making up for the air in the system....i gotta get the air out... or find out where it is coming from....thanks
I would recommend to use only a NON fail safe thermostat. Those little fail safe mf'rs stick like hell. I always microwave some water and stick my a/c vent gauge into the water till its to thermostat specified temp and drop the t-stat in the water and see if it actually opens. Two out of five don't open. Its just cheap chinese shit now and you have to double check it. Also is it possible your radiator is clogged? Poor flow or blockage will kill it.
I say putting it in gear and driving it down the road will cure the problem. If a box fan pushes enough air through the radiator to cool it, imagine what 20 MPH will do. You may still have a problem stuck in traffic, or in a parade, but as mentioned before, if it's a new engine build, it's going to run hot for a awhile because, if it was done right, it's a little tight unitl it breaks in. I wouldn't go making a bunch of changes until it's broke in and on the road.
Has anyone asked about you running a "high flow" water pump you might be pushing water faster than what it can cool in your radiator. Or is it a stock pump I;ve had that problem before.
Comments about the water flowing to fast to cool in the radiator. I used to believe it too. That is, until someone explained to me that if the water is flowing too fast to transfer heat in the radiator, then it's running too fast through the block to fast to transfer heat away from the engine. Believe it or not, I have never fixed a cooling issue by slowing anything down.
One thing I do on all my cars when I install a new thermostat is drill a 1/8 hole in it. Keeps it from getting a air bubble behind it and not opening. Also makes it easier to fill the system, because you dont have to wait for the thermo to open, and add more water. This may or may not apply to SBC's.
Have you tried a fan spacer? is it possible that your fan is too far away from the radiator and is creating more turbulence than pull? I'm thinking like a 1 inch spacer i think Mr Gasket has them for like $7.
Haven't read every post here, but having raced oval track cars on and off for last 16 yrs I have learned all the tricks to cool a 600 hp engine on gas which is a lot harder than a street engine. So if I repeat anything someone else has said, I'm sorry. This is what works. #1. At least 1:1 pulley ratio. Meaning water pump spins at least as fast as motor rpm. This is probably the most important thing. #2. High flow alum. water pump. There is no truth to the rumor that fast moving water will not have time to cool in the radiator, and the higher flow helps to eliminate captivation and hot spots in the motor. #3. A steel non flex fan. Do NOT use a flex fan! 5 blade is ok for street. We use a 4 blade for racing because it pulls more air at higher rpm's. #4. A fan shroud. That's a no brainier. #5. We don't use a thermostat in the race engines but you should drill a small hole in it to help bleed the air out of the system. Pretty much every circle track guy is running this exact set up unless he's running alcohol which runs much cooler. Look up Howard Stewart water pumps. Their site has a lot of good info. Good luck!
In the 80's when Howard Stewart started the water pump company I saw his water pump dyno. Sometimes without a thermostat or a restrictor in its place the water pump cavitated. That slowed the flow through the whole system. Like Elpolacko said goin' through the radiator fast is not a problem. Look how fast water goes through a heater core and they transfer heat. They even have a bigger diameter tube and less fins than a radiator. Smokey
update>>>> thanks for all your help...i think i got it to run cool..it was a combo of things everything i tried helped a little... # 1 fan placement in the shroud #2 flowcooler water pump...#3 no thermo stat....#4 changed the dist advance...it will idle at 175 185 degrees for an hour at a time ...maybe this info will help the next guy..thanks again
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