Vette Powered Posted August 31, 2009 Share Posted August 31, 2009 Hey guys. I've got my car up and running strong but she runs hot. It's a 1978 350/383 Stroker that's built up with Dart heads, MSD, Crane cam., etc... It has a big aluminum radiator and the Ford Torus fan. I'm also running a vintage mini A/C aswell. Anyway, I spent a day with a friend flushing the system, new thermostat 185, fan is on thermostat aswell, and even jacked the front of the car up to get all the air bubbles out. I added slick water and new water/coolant. It runs at about 190 or so Nd I live in Texas so it's hot but If I turn the A/C on and sit at a light it wants to climb to 220 or so and fast to. Anyway, any thoughts would be helpful. Thanks guys. Quote Link to comment Share on other sites More sharing options...
datsun79z Posted August 31, 2009 Share Posted August 31, 2009 The A/C compressor puts quite a load on the engine, and that creates additional heat. It sounds like you are running an electric fan. If so the fan MUST be wired so as when you turn on the A/C the fan will run continuously. If the fan does not run the entire time the A/C is on your engine will overheat. Worse yet, head pressure will build in the A/C compressor to the point of ruining it. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted August 31, 2009 Share Posted August 31, 2009 did you seal the fan to the radiator? have you blocked the upper or lower portion of the grill and made and air box? are you using under drive pulleys? are you using the stock water pump? is the fan working on both speeds or just one? Quote Link to comment Share on other sites More sharing options...
Vette Powered Posted August 31, 2009 Author Share Posted August 31, 2009 The A/C compressor puts quite a load on the engine, and that creates additional heat. It sounds like you are running an electric fan. If so the fan MUST be wired so as when you turn on the A/C the fan will run continuously. If the fan does not run the entire time the A/C is on your engine will overheat. Worse yet, head pressure will build in the A/C compressor to the point of ruining it. Fan is running all the time. I have a 185 thermostat for the fan and believe me...the car always runs above that!! That's what I'm worried about though. I really don't want to hurt the motor or A/C etc. Quote Link to comment Share on other sites More sharing options...
jt1 Posted August 31, 2009 Share Posted August 31, 2009 You might try drilling a couple of 1/8" holes in the thermostat flange to help get the air out of the engine. Sometimes that can make a difference. jt Quote Link to comment Share on other sites More sharing options...
Vette Powered Posted August 31, 2009 Author Share Posted August 31, 2009 did you seal the fan to the radiator? have you blocked the upper or lower portion of the grill and made and air box? are you using under drive pulleys? are you using the stock water pump? is the fan working on both speeds or just one? Ok... Let me see if I can answer these questions. Fan is sealed to radiator, no air box made but I've been studying on it and want to build one, yes I have under drive pulleys, pump is big, and the fan is wired to run on high always. Quote Link to comment Share on other sites More sharing options...
John Scott Posted August 31, 2009 Share Posted August 31, 2009 Why such a hot thermostat? 160 or none (flame on with that one http://www.stewartcomponents.com/tech_tips/Tech_Tips_3.htm ) will be better. Quote Link to comment Share on other sites More sharing options...
Vette Powered Posted August 31, 2009 Author Share Posted August 31, 2009 I have the fan and the coolent thermostat at 185. That's a good point cuz when I was testing the first time I left the thermostat out and ran just water. It seemed to run cool then but I never ran it long. Maybe I'll get a 165 for the engine and keep the 185 for the fan. 165 both??? Quote Link to comment Share on other sites More sharing options...
rucus01 Posted August 31, 2009 Share Posted August 31, 2009 Hey guys. I've got my car up and running strong but she runs hot. It's a 1978 350/383 Stroker that's built up with Dart heads, MSD, Crane cam., etc... It has a big aluminum radiator and the Ford Torus fan. I'm also running a vintage mini A/C aswell. Anyway, I spent a day with a friend flushing the system, new thermostat 185, fan is on thermostat aswell, and even jacked the front of the car up to get all the air bubbles out. I added slick water and new water/coolant. It runs at about 190 or so Nd I live in Texas so it's hot but If I turn the A/C on and sit at a light it wants to climb to 220 or so and fast to. Anyway, any thoughts would be helpful. Thanks guys. What fan are you using? What is the CFM rating on it? I found with my setup the that E fan makes more difference than anything else you can buy. You need a good shroud to make sure the air is pulling directly through the radiator and a fan with a good cfm rating. Go to the yard and find one of the ugly model ford taurus and pull the E-fan from it. It moves more air then the expensive flexalites and will cost you about $15. Quote Link to comment Share on other sites More sharing options...
Vette Powered Posted August 31, 2009 Author Share Posted August 31, 2009 What fan are you using? What is the CFM rating on it? I found with my setup the that E fan makes more difference than anything else you can buy. You need a good shroud to make sure the air is pulling directly through the radiator and a fan with a good cfm rating. Go to the yard and find one of the ugly model ford taurus and pull the E-fan from it. It moves more air then the expensive flexalites and will cost you about $15. Yah... That's the fan I've got on it. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted September 1, 2009 Share Posted September 1, 2009 i think you have stalled air in front of your radiator, try sealing off the upper portion of the grill and sealing the holes in the core support. Quote Link to comment Share on other sites More sharing options...
Vette Powered Posted September 1, 2009 Author Share Posted September 1, 2009 i think you have stalled air in front of your radiator, try sealing off the upper portion of the grill and sealing the holes in the core support. I'm doing some research in the wild tunnel forum. I'm going to go get some sheet metal and hope I figure something out. Quote Link to comment Share on other sites More sharing options...
datsun79z Posted September 1, 2009 Share Posted September 1, 2009 Vette Powered; Sorry to hear you are still having issues. One question, as silly as it may seem. Is there any chance the thermastat is installed backwards? Also, you may want to remove the thermastat and run the car without one for a short time. See what happens then. It should run very cool almost all the tme. Keep us posted. Mike Quote Link to comment Share on other sites More sharing options...
rsicard Posted September 1, 2009 Share Posted September 1, 2009 Vette Powered: Do as suggested and remove the thermostat and run it that way to determine if it runs much cooler. Also when the thermostat is removed, look at the coolant flow at the radiator cap opening to see if there is GOOD flow. Many GM waterpumps are inadequate. Purchase a EMP Stewart water pump as these are always VERY GOOD at flowing coolant. Other than that there may be a restriction somewhere in the cooling system. Quote Link to comment Share on other sites More sharing options...
jnjdragracing Posted September 1, 2009 Share Posted September 1, 2009 From my experience I would make sure the radiator is clean and is flowing properly along with the water pump. Also the following reasons for a thermostat is to get the engine warm for heat, also its purpose is to open and allow water to the radiator to be cooled then open again (cycling). If it is too low then it will open and never close to allow the water in the radiator to be cooled. If a 185 is not doing the job and the radiator and water pump check out then go up to a 195 and see how it does. John Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 1, 2009 Share Posted September 1, 2009 Heating problems are always a nightmare. Ample pump flow, retention time in the rad, airflow are the key. Alum rads are more efficient, so it's probably just adequate air flow. The 160 or 165 stat will work fine if you use one and will make more power IMO. Air flow problems can be the result of insufficient shrouding/sealing and IMO is the place to look in your case. Quote Link to comment Share on other sites More sharing options...
Vette Powered Posted September 1, 2009 Author Share Posted September 1, 2009 Vette Powered; Sorry to hear you are still having issues. One question, as silly as it may seem. Is there any chance the thermastat is installed backwards? Also, you may want to remove the thermastat and run the car without one for a short time. See what happens then. It should run very cool almost all the tme. Keep us posted. Mike Yah I checked and it's in right. I ran the car today for about 30 minutes in 95 degree heat and it stayed under 200. If I run the a/c though she heats right up. I think I might try running no thermostat for awhile. Thanks... Quote Link to comment Share on other sites More sharing options...
Vette Powered Posted September 1, 2009 Author Share Posted September 1, 2009 Vette Powered: Do as suggested and remove the thermostat and run it that way to determine if it runs much cooler. Also when the thermostat is removed, look at the coolant flow at the radiator cap opening to see if there is GOOD flow. Many GM waterpumps are inadequate. Purchase a EMP Stewart water pump as these are always VERY GOOD at flowing coolant. Other than that there may be a restriction somewhere in the cooling system. I did this a couple of times and I've got really good flow. Quote Link to comment Share on other sites More sharing options...
Vette Powered Posted September 1, 2009 Author Share Posted September 1, 2009 From my experience I would make sure the radiator is clean and is flowing properly along with the water pump. Also the following reasons for a thermostat is to get the engine warm for heat, also its purpose is to open and allow water to the radiator to be cooled then open again (cycling). If it is too low then it will open and never close to allow the water in the radiator to be cooled. If a 185 is not doing the job and the radiator and water pump check out then go up to a 195 and see how it does. John I don't understand??? Run a hotter thermostat? I was going to try it with no thermostat and then maybe try a 165. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted September 2, 2009 Share Posted September 2, 2009 its easier to keep coolant cool, then to try and cool hot coolant (for those who dont know) your problem (if the front is stock) is most likely going to be air flow through the radiator. (and adding a hotter thermostat will only make it worse) the acronym k.i.s.s applies here. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.