Temp problem

Status
Not open for further replies.

rccktmn2

Greasemonkey
Mar 11, 2008
196
1
18
Paulding Ohio
Long story short, just finished my car it's an 84 cutlass, 455 big block, a/c delete, hooker super comp headers, torker intake, etc. The issue is when I took it out to the gas station (5-6 miles away) it was running around 185 when I stopped at the gas station (it has a 160 thermostat in it) on the way back the temp kept climbing till it hit 230 and I shut it down. The radiator is a 2 row aluminum with dual electric fans with a shroud (yes the shroud is spaced out from the radiator), the fans were on all the time (manual switch controlled-no thermostat). So I let it cool down when I got it home, checked all the fluids, started it and let it run for about 5 min, shut it off and pulled the thermostat housing and thermostat and put a thermometer directly in the coolant and it read 168 degrees. So I'm thinking something is wrong with the thermostat, removed thermostat and ran it, car maintained anywhere from 195-210 unless your sitting still and then it makes it to 220 so I just kept driving. Got home and checked it with a temp gun at the water pump engine was 210, radiator was at 170 no matter where I took the temp at, checked the temp pretty much all over the engine and got around the same temp of 205-210. Theoretically it is my belief that the engine and radiator should be the same temp not different indicating something is definitely wrong.
 

pontiacgp

blank
Mar 31, 2006
29,270
20,391
113
Kitchener, Ontario
Without a thermostat the flow is too quick to pull heat from the engine. The engine block may be overheating but the fluid temperature would not show that. Antifreeze is very poor at pulling heat off the block so if you just run your car in the summer you can run distilled water and water wetter or an equivalent product. When you deleted the ac did you remove the condenser so there is nothing interfering with the airflow through the radiator
 

rccktmn2

Greasemonkey
Mar 11, 2008
196
1
18
Paulding Ohio
The only thing in front of the radiator is the trans cooler so I don't think it's an airflow problem with the radiator, when I built the fan shroud I spaced it away from the radiator enough to get airflow at all corners of the radiator. I pulled the water pump off and checked it over and I didn't notice it before but the impeller does not have vanes on it, it has little vanes like a paddle wheel but they are very small about a 1/4 inch in length and do not reach all the way back to the center.
 
Oct 14, 2008
8,806
7,746
113
Melville,Saskatchewan
Disagree on the flow too fast without a thermostat. The only time my Cutlass got hot was towing in heat, same as a thermostat. A thermostat is a good idea, get the EP Stewart modified Robert Shaw thermostat, NOT the Mr Gasket one, junk! What size and brand rad? What fans? I run Dodge Stratus fans. Get a Flowkooler or Milidon high flow pump. Also NO under drive pulleys! I went through this with my Olds 403, bad Mr Gasket thermostat gave many head aches. I also found a good size two core cools better than a 3 core.
 

pontiacgp

blank
Mar 31, 2006
29,270
20,391
113
Kitchener, Ontario
olds307 and 403 said:
Disagree on the flow too fast without a thermostat.

That was not my opinion, it's a fact but if you don't believe it boil a couple of eggs. Take one and stick it under running water for 20 seconds. Take another one and stick in a bowl of cool water for 20 seconds. Which one is cooler? The one in the bowl, transfers more heat into the water.
 
Oct 14, 2008
8,806
7,746
113
Melville,Saskatchewan
Real Olds Power's cooling system expert disagrees, he is an engineer. As do I and many others. My 403 ran much cooler at idle without and similar at high speeds without a Thermostat. It did eventually hit 235 pulling in heat, thermostat or not. The restriction on a high flow thermostat is very little anyways. My 3 core Champion just wasn't big enough, it was the cause. I put a thermostat back in to keep the temp more constant and have heat putting around. There is also the disagreement of high quality, big tube 2 cores vs 4 core rads. The consensus is the big two core rads are best. My current 2 core sure runs cooler than my Champion 3 core.
 

jociha

Master Mechanic
Oct 16, 2012
279
1
18
Sounds like the radiator can not keep up. Get a good tstat and drill a small hole in it to let air thru. Yes you will overheat without one as the radiator can not transfer heat if the water moves past to fast or get a restrictor, that is why they make them. You need a better radiator, get a cheap china Champion and you will continue to have problems. You need at least 2 rows of 1" tubes if aluminum or 4 rows of 1/2" tubes if copper and good fans.
 

pontiacgp

blank
Mar 31, 2006
29,270
20,391
113
Kitchener, Ontario
Race cars have an issue trying to stay cool and their engines are worth a bunch $$$. They have engineers working on them too and those who do not want to run a thermostat for the fear for it seizing up will run a restrictor plate instead to simulate a thermostat. If no thermostat would reduce the engines temperature we'd remove the plate. We also have a oil temp gauge and that tells us if the engine itself is running too hot since the oil temp should be a few degrees hotter then the coolant temp. Your coolant may run cooler but the engine block will be hotter than the coolant since the coolant was not able to absorb the heat from the block.
 

rccktmn2

Greasemonkey
Mar 11, 2008
196
1
18
Paulding Ohio
ok, well over the weekend I replaced the water pump with a flowkooler water pump, wow what a difference, you can see the flow all the way through the radiator. I also put in a new 160 degree thermostat which also helped. Running down the road it stays a steady 195-200 degrees with no problems. My next question is what is a normal temp for a 455, turbo 350 and 4:11 gears, doing about 55-60 it runs about 3000 rpm.
 
Status
Not open for further replies.

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor