Just so everyone knows... In the Buick last summer I drained all I could get out of the radiataor and block. There is always something left in the block so I can't say I drained 100% of the coolant. I then added the Redline water wetter and filled with tap water. I went for a test drive and the engine temp was unchanged. It started creeping hotter and hotter at the same light the same way as it did the day before. I agree, even though I've seen no evidence, that a 50/50 mixture transfers more heat than 100% antifreeze. I also agree that you need to change your coolant regularly. I'm willing to test my theories and others theories. I believe in unbiased scientific testing. I am skeptical of wives tales, rumors, advertising, manufacturers recommendations and urban legends. I'll admit, I haven't done a decent scientific test on 100% antifreeze. I just tried it in my vehicles and it works for me. I'd love to see some real evidence on this subject. Years ago I took two glass bottles and put a piece of aluminum, steel and cast iron in the bottom. I then filled one with 100% antifreeze and the other with a 50/50 mix. Over time there was a little oxidation in the bottle that had the 50/50 and the metal in the 100% bottle looked new. I still have these bottles if anyone wants me to post a pic. I can't say this test is accurate because the liquids don't see the same conditions that they would in an automotive cooling system.
What kind of modifications are we talking about exactly uzzled: ? If getting the rpm's up cools the car down then I'm thinking that it's pretty obvious that the water pump isn't moving enough coolant--especially at low rpm's. Go with new stock replacement pump or a brand name high flow one from summit and I'd bet that the problem goes away....
Great question! After some research I learned that with a four core radiator you need a high volume water pump. I also learned that very few companies sell one for the 350 Buick. I bought one from Summit. flow-kooler pump It was a couple inches too long :rant: It was my fault, I didn't look at the applications page. I just saw buick 350 and figured that will fit. I learned that 1973 and up used a long nose pump. I compared that pump to mine and saw the only thing they did was to weld a round piece of sheet metal to the engine side of the impeller. The impellers are the same diameter and thickness with the same amount of vanes. I called Summit and they said they would take it back but the pump for my car is a special order part. So there I was with my stuff all apart. I need the car on occasion so it can't be offline for long. So I decided to copy the "Flow Kooler" pump. I welded a piece of sheet metal on my impeller exactly like the one on the "Flow-Cooler" pump. My impeller is made of cast aluminum so I used aluminum sheet. Their impeller was cast iron. Did this mod make a difference in the volume of water? I can't say. Did this mod make the car run cooler? Nope. I am happy I didn't spend the money on the "flow Kooler" pump only to see the problem was still there. Today I counted the amount of tubes in my 4 core radiator and found that there are 27 per core for a total of 108. Thats more than a Harrison 2 core but less than a Harrison 3 core. Does anyone know what radiator a 1970 GS350 with A/C had and was there a different water pump? EDIT: I looked closer at the "Flow Kooler" impeller and it is different than the pump I have on the car now. I also bought a new pump from NAPA in case my mod went bad. The NAPA pump has the same impeller as the "Flow Kooler." My old pump has 6 full vanes and these new impellers have 3 full and 3 partial vanes. Are these new impellers better? The NAPA pump is on the left.
I guess I should have asked this question? When you say running hot or over heating do you mean high temps or an actual boil out? If you are not experiencing boil out it is not the cap failing. The purpose of the radiator cap is to maintain a safe system pressure not the temperature (but it does increase the boil point allowing water to run at a higher temp). The thermostat on the other hand is the control valve preset to a temperature that allows the hot motor coolant to be exchanged with the cooled fluid in the radiator. As for the chemical make up of automotive antifreeze I would say running more then 50% for cooling purpose is not right. I would have to say the antifreeze companies would LOVE it if this was true because you would have to buy more! I am not a motor type person but would have to say if your cooling hardware is new and functioning properly, Radiator, Coolant, Thermostat, Shroud, Fan and hoses? How are the water jackets in the block? Are you sure all the passages are clear? Also (and I dont know) I see a lot of guys are running 160 and 180 thermostats. Are these realistic temperatures that can be maintained by a street car? I mean your motor is a constant source of heat (exothermic) and once you overwhelm your cooling system and the thermostat stays open its not going to get any cooler! I am running a 200ish all weather (Need the heat on in the Fall) thermostat and it never moves after warm up. And with the A/C on it spiked to 230 only once before I cleaned my radiator good. On a side note my automotive experience is limited. I am a chemical reactor operator and do know a lot about heat transfer and boiling points. I ran a 6000 gallon reactor (picture a gasoline tanker standing straight up). Most people think of boiling liquids as water in a neutral atmosphere. I deal with range of fluids from Phenols to Isopropyl Alcohols. Everything has its on boiling point and heat transfer rate. Then put in under 27 inches of vacuum it boils at half the temperature or 15 lbs of pressure and it maximizes its boil point. Again if all your external cooling pieces are working and flowing what could be restricted in the motor? Would any of your after market part have a gasket that maybe partly blocking something? PS: My Chemical tip of the day. When choosing a transfer media make sure it is an absorbent not an adsorbent. Mark
IF the rest of the cooling system is up to the task, yes, you can maintain 160. It's stupid, though. 160 thermostats got a big boost in sales because of computer-feedback vehicles with lean fuel metering. Popping in a 160 thermostat "tricks" the computer into enrichening the mixture, and SHAZZAM, more power. So people think that 160 thermostats are good for more power in ANY application, 'cause they work like magic in SOME applications. And the irony is that it isn't the temperature that's responsible for the power, it's the fuel enrichment caused by the computer thinking the engine isn't fully warm yet. It's like taking medicine because you want the side effects. Another use for "cold" thermostats is to crutch a defective cooling system for awhile. I have no use for a 160 'stat.
Mark, My 350 has never boiled over. I suppose the temp may stop climbing at some point but I haven't let it get past 210. The vapor lock makes the car undriveable. Back in 1992 when I first experienced this problem I was waiting in traffic to go over the Delaware Memorial bridge. I was towing a boat. The vapor lock was so bad I barely made it over the bridge. The car backfired near the top of the bridge and blew out both mufflers. I ended up running the heater most of the way to South Carolina. Running the heater wide open kept the engine temps under control. Thats why I figured the radiator was bad. That was one hot trip! Shurkey, I installed the 160 stat because I found out that a 180 stat only cracks open at 180. It takes it until 200 to fully open. There is very little water flow at 180. That works in cool weather. My engine will run 180 when its 70 or below ambient. I want my engine to run at 180 and I couldn't see how it would ever stay at 180 in the summer with that small amount of water flowing through the radiator. I'm trying to find this problem so I'll try anything that makes sense to me. The 180 stat is on the left...
There are high-flow thermostats available (like Stewart), everyone with cooling issues should have one.
I changed the vacuum advance from ported to unported and tested it today. The engine doesn't ping. I have the vacuum advance set for 6 degrees so with my 11 initial I now have 17 at idle. The engine temp still creeps up when sitting in traffic. This change didn't solve the problem. The vapor lock symptoms seemed to improve though. I may look into a heat shield for the holley. I also checked my float levels over the weekend. They were fine, about an 1/8 inch under the weep holes. I also checked the temp of the fuel in the front bowl. It was right around 120 degrees with the hood open and the engine around 190. I suspect it gets hotter with the hood closed and the a/c on. I haven't found the boiling temp of gasoline. Evidently is varies quite a bit so I'll have to do a test to see where my fuel boils. Now I'm thinking my 4 core radiator might not be cutting it.
I was having a similar problem as you. When the temp were around 85-95 here my car was running around 210-230. This was with a 3 row radiator, electric fans from an intrepid and a water pump dated 10-19-83( water pump's older than i am :laugh: ). So i changed the water pump and now i have control over the temps. The fans come on around 195 and turn off around 180 and they actually turn off now. When examining the old water pump i noticed that coolant was dripping from the weep hole, which might explain why the cooling system wasn't holding alot of pressure. I guess what i am getting at is make sure the are no leaks and that the cooling system holds pressure, lack of pressure will cause the engine to run hotter than normal. Also i am running as little antifreeze as possible and i can see the difference on the temp gauge. Jeramie
Thanks Jeramie, That's good info. My system holds pressure for sure but I do wonder about the water pump impeller design change over the years. The pump on the car now has an 85 on it. I'm thinking that may be the mfg date. I installed it in 1992 shortly before I parked the car. The new pumps have a different design impeller but I don't know for sure if they flow better or not.
UPDATE: switching to unported vacuum seemed to have slowed down the creeping and the vapor lock situation. She still creeped up but I could run the a/c almost all the time in the traffic. It all depends on the ambient temps and how long the stop and go traffic is. Last weekend I had the car out on the interstate for the first time in 11 years. I was running the a/c and was suprised to see that the faster I went the hotter she ran. At 70 MPH temp was 190. At 80 MPH temp was 200. Over 80 MPH she creeped to 210 and I cut off the a/c. I knew right then my new 4 core radiator from Postons was junk. At 2500 RPM and 90 MPH there has to be enough air and water flow. At least I now know what I need to do... :beer Also I'm pretty sure the vapor lock I'm experiencing is the fuel boiling in the accelerator pumps in the Holley DP. They hang right at the bottom of the bowls just above the hot intake manifold. I'm betting a heat shield would solve that problem. I figured this out because when I park the car for 5 to 15 minutes with the engine is hot it's a little hard to start and is loaded up with fuel. Less than 5 minutes she starts right up. More than 20 min and it starts right up. One day when I got home, engine hot, I opened the hood removed the air cleaner and watched. For the first 5 min nothing happened. Then right at about 5 minuted after I shut it down, fuel started weeping out of the front and rear accelerator pump nozzels. This lasted for a few minutes and then stopped. Mystery solved.
My '65 with a 180 stat runs 200 all the time (or thereabouts)..In colder weather it runs about 192...last week when it was 100, it was running about 205-208 on the highway. Remember that these cars had a light and not a gauge when new...people get nervous about 200, but like you said, a 180 thermostat won't be fully open til 200 or so...I don't think the light on the dash came on until 240 or so...but with that said, the temp creeping up to 220 and more on the highway is an issue that probably should be addressed...my '53 overheated (like boiling over hot) until I had the radiator boiled out at the radiator shop...so, I'd say radiator or water pump...
Sounds like you need more radiator cooling capacity. You can go with a 2-row (1") aluminum unit; has 82 total tubes, each tube is 1". There are universal-fit type ones you can get for under $200. www.streetrodstuff.com can build you a custom one for $400. As far as copper-brass radiators go, you'll get the most capacity in a re-core. You can go through a local rad shop, and have them order and build one or go through the core maker yourself and get one built locally. In order of capacity from more to less: Radac "D" core, 4-rows. Will have 172 tubes that are 5/8" . www.radac.com Optima 4-row from US Radiator. Will have 208 tubes that are 1/2". ($500) Proliance (used to be GDI) "G" core 3-row (will be 3" thick). Has 114 of 3/4" tubes. Proliance (used to be GDI) "VX" core 3-row. Has 132 of 5/8" tubes. All will have more capacity than the original 4-row Harrison. The first 3 will have the same or more capacity than a 1" 2-row aluminum.
use one of these---there is no comparison between these and the other brand "HD" type thermostats. The Mr Gasket one is made by RobertShaw and available @Summit and JEGs. The stats in the RobertShaw box were purchased from Stewart Components...same stats If you aren't running one of these then you are keeping one hand tied behind your back while chasing down this cooling problem...the stats you pictured will not flow like these. Eliminate a potential "problem" area.
Heres a trick I've used on Chebby SB 400's, which are prone to overheating. Take a standard 180 deg. thermostat and drill a 1/4 inch bypass hole in the flange. Steam buildup in the block can slow, or prevent, circulation after the thermostat opens. The bypass hole vents any steam that might build and only slightly increases flow. Just a thought. Jay K. Memphis
I use this fan on my GN. IT's THE BOMB! I wish I knew about this thing before I bought a flex-a-lite system for my 455. I'm not saying that my flex-a-lite doesn't work well either, it's just that the RF-64 fan is a mother-sucker! You can even feel the air going into the car, standing in front. I'd love to try one of these on a Buick V8 some day, and will post results. ElectraJim
