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Have an anniversary 427 aluminum engine. Engine temp of late has been in the 210 range. No expansion tank on board so when I shut down I have quite a bit of radiator fluid to collect. Now it has been hot outside so that accounts for some of the heat. The front license plate is in the center position. I have changed thermostats. Fan blades seem OK. I have even considered Purple Ice. What else might I be looking for to get the temp back in the 180 range?
[QUOTEWhat else might I be looking for to get the temp back in the 180 range?[/QUOTE]
a fan shroud, an actual radiator FOR a big block, a stuck t stat, fan too close to radiator, a failing water pump, and a head gasket leak in a pear tree.
Snake Oil Alert: purple ice only works with pure water. ( no coolant). A proper cooling system doesnt need "purple ice"
Do you have a fan shroud installed? Have you checked temps with an IR gun to verify the gage accuracy? Big blocks like a fair amount of timing at idle and low speed to keep their cool. If you have vacuum advance make sure it working and hooked to a full time vacuum source - which is from somewhere under the throttle blades. Make sure your initial timing is somewhere in the 10 -14 degree range although that is going to depend on how your distributor is set up and how much centrifugal advance it brings in to keep it all in the 36 deg range.
Finally, if 210 is a peak you are getting while sitting at a light or in slow traffic, that's probably not going to hurt anything. If it comes down a little when moving it's probably OK.
[QUOTEWhat else might I be looking for to get the temp back in the 180 range?
a fan shroud, an actual radiator FOR a big block, a stuck t stat, fan too close to radiator, a failing water pump, and a head gasket leak in a pear tree.
Snake Oil Alert: purple ice only works with pure water. ( no coolant). A proper cooling system doesnt need "purple ice"[/QUOTE]
Thanks for the note. Will check the items you note.
Have replaced the t stat. Water pump is new and there is a shroud in place. The radiator came with the car so will confirm that it is in fact a big block version.
Thank you.
Do you have a fan shroud installed? Have you checked temps with an IR gun to verify the gage accuracy? Big blocks like a fair amount of timing at idle and low speed to keep their cool. If you have vacuum advance make sure it working and hooked to a full time vacuum source - which is from somewhere under the throttle blades. Make sure your initial timing is somewhere in the 10 -14 degree range although that is going to depend on how your distributor is set up and how much centrifugal advance it brings in to keep it all in the 36 deg range.
Finally, if 210 is a peak you are getting while sitting at a light or in slow traffic, that's probably not going to hurt anything. If it comes down a little when moving it's probably OK.
Thanks. Good advice all. I don't have an IR gun but can tell from your note that I need one. The one reason I have the concern is the amount of overflow that I get after a trip. I will confirm the timing issue as it have been a while since doing that. I have replaced the t stat. Not sure how to check the fan clutch from a standing position other than to replace it. As for the 210, just in the last two runs has the temp reached those levels. That tells me something has changed causing the temp to run higher than any time previously.
RCS116427;1592924985
Engine temp of late has been in the 210 range. No expansion tank on board so when I shut down I have quite a bit of radiator fluid to collect
My BB (390hp) runs in the 180-190 range in outside temps below the mid 80's, anything above that it seems to hover around 190-200 going down the road.
I did get caught in traffic for the first time a couple weeks ago in the AM and my temp climbed to 220. On the way back home a few hours later with outside temps in the 90's my temp was running around 200-210. Once I parked the car I shot it with my IR gun and the T-Stat housing was 200 and the temp gauge was 210.
Guess what I'm trying to say is my car runs on the hot side around 200-210 with a bounce to 220 but I have never experienced a loss of coolant through the overflow.
My BB will climb to 210-215 while sitting with the air condition on.
I ,was also, having overflow problems with no expansion tank at shut down. I leave the water level just a little low in the radiator so it will have room for expansion when hot. Good Luck.
My BB (390hp) runs in the 180-190 range in outside temps below the mid 80's, anything above that it seems to hover around 190-200 going down the road.
I did get caught in traffic for the first time a couple weeks ago in the AM and my temp climbed to 220. On the way back home a few hours later with outside temps in the 90's my temp was running around 200-210. Once I parked the car I shot it with my IR gun and the T-Stat housing was 200 and the temp gauge was 210.
Guess what I'm trying to say is my car runs on the hot side around 200-210 with a bounce to 220 but I have never experienced a loss of coolant through the overflow.
Maybe you should try a new radiator cap.
Thanks. Solid advice indeed. I will get a new radiator cap. How many # version should I be looking for? The current cap is a 7# fellow.
From the notes received here I need to get an IR gun. Is there anything to the story that BB had an optional front license location just for airflow through the radiator? And I have a 67 coupe that also has factory air. With this version there is no room for an expansion tank. Years back I had a 67 with 350 with an expansion tank and had no problems at all.
Thanks. Solid advice indeed. I will get a new radiator cap. How many # version should I be looking for? The current cap is a 7# fellow.
From the notes received here I need to get an IR gun. Is there anything to the story that BB had an optional front license location just for airflow through the radiator? And I have a 67 coupe that also has factory air. With this version there is no room for an expansion tank. Years back I had a 67 with 350 with an expansion tank and had no problems at all.
Is it possible you are over filling the radiator? Look on the side of the tank and it will say Fill to this level or fill here cold and its 2/3 inches below the top of radiator.
Is it possible you are over filling the radiator? Look on the side of the tank and it will say Fill to this level or fill here cold and its 2/3 inches below the top of radiator.
Thanks. I have not seen the mark on the tank you mention. Will check that to be sure I am not overfilling. Good advice. Thank you.
Despite earlier experience in the use of aluminum for automobile cylinder heads, little data were available in connection with metal temperatures of aluminum versus cast iron in operating engines. This paper is concerned with extensive testing of both types of material and shows the feasibility of all-aluminum engine blocks and cylinder heads, with the aluminum engine operating at lower temperatures under varying conditions of speed, coolant, fuel, and similar factors.
If you use a 15# cap the radiator won't boil until you reach 250-degrees.
The important thing is that you only use distilled water in the cooling system. Tap water is not good for the cooling system. DeWitt say that most of the radiators that are sent back under warranty are a result of people using tap water.
Purple Ice is really a surfactant. It's very similar to Water Wetter and Below 40. The idea is that by changing the surface tension of the water you will change the thermodynamic flow from the water to the radiator tube. The surfactant actually allows more of the water molecule’s surface to come into contact with the tubing in the radiator. It changes the water molecule from a sphere to an oval shape.
Here's the trick though. Most anti-freeze already has a surfactant in it. Adding more surfactant won't make a difference. Water Wetter, Purple Ice, and Below 40 only works with distilled water. You simply don't need it if you're using antifreeze.
Finally got back to work the overheating issue on the 427 Anniversary Engine.
I changed the fan clutch out and everything works great. I ran every combination of RPM and load ranges. The temp gauge stayed near 180 the whole trip.
I did have to go to the aftermarket to get the clutch. Local GM dealer said there is no way you will get an original part for a 67. So I went to Corvette Central and the new part works great. Thanks for all the earlier advice.
08-25-2016, 08:14 PM
Big block overheating
