B.Liesberg Posted October 4, 2018 Share Posted October 4, 2018 I'm still having overheating troubles in traffic, I cleaned out the cooling system and have fresh coolant. The thermostat currently in the engine is a standard 160 degree. I have a spare 160 hi-flow, would it be better to install that one or would that cause the coolant to flow through the radiator too fast? Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted October 4, 2018 Share Posted October 4, 2018 When you say you cleaned out the cooling system, just what was done? IF the radiator was not removed and rodded out, you are spitting into the wind. Nothing you do is going to help if it is not CLEAN. Ben Link to comment Share on other sites More sharing options...
B.Liesberg Posted October 4, 2018 Author Share Posted October 4, 2018 Calm down, I was just asking a question. I ran it with washing soda for about an hour, flushed it for a week with Vaporust , rinsed twice, and checked with a bore o scope. The inside looks fairly clean. If I end up removing the radiator for any reason I wouldn't mind taking it to the shop, but it looks like quite a hassle to remove. I wanted to ask about the thermostat first because it's cheaper/easier to work up from the simple solutions instead of run right to the most labor intensive/costly one and work down. Reminds me of the 2 guys who went cross country in their flatfenders, and one of them was unable to get the engine to engage the driveshaft, they spent a day disassembling the entire drivetrain assembly on the side of the road in the desert, only to find out the transfer case was in neutral. 2 Link to comment Share on other sites More sharing options...
Gary W Posted October 4, 2018 Share Posted October 4, 2018 You can try to run it without a thermostat and see what happens. Drop your thermostat in a pan of water with a thermometer. Heat it up and see if it is actually functioning as it should. When the water temp hits about 140 the thermostat should start to open. At 160 it should be fully open. Maybe you have a bad one that is limiting the water flow. Good Luck. 2 Link to comment Share on other sites More sharing options...
DonMicheletti Posted October 5, 2018 Share Posted October 5, 2018 Overheating in these engines is a very common problem. In many cases the basic problem is crud in the water jacket at the back of the block. These long engines have a problem with that. It is a lot of work, but a big part of the solution is to knock out all the core plugs and clean the crud out of the water jacket. If there is lot of crud in the water jacket, nothing you do will solve the overheating problem. A clean water jacket usually solves the problem. Of course the radiator must be clean too. You can try the thermostat first - it is easy.I doubt it will help. I do wish you luck on that though. The radiator is a bear to remove. 1 Link to comment Share on other sites More sharing options...
Gary W Posted October 5, 2018 Share Posted October 5, 2018 Of course, Don is correct. The only way to be sure she'll run cool is to clean out all crud in the block, and then rod or record the radiator. When I had my block out of the car, I did just this. With the block out of the car, it was much easier to knock out the freeze plugs . You can see how much crud was inside the block. I spent half an hour with a power washer and blew out the block in every direction, in and out of every water port. When I was done, the block was nice and clean inside. I also sent my radiator out and had it recored with a high efficiency core. I also tested my thermostat before I installed it to be sure it operates correctly before I used it. I hope it will run nice and cool. I mentioned trying to run it without the thermostat as a simple diagnostic test to rule out the thermostat as your problem. If she still runs hot with the thermostat removed, unfortunately you have other problems that need to be addressed. You'll get to the solution! Gary 1 Link to comment Share on other sites More sharing options...
B.Liesberg Posted October 5, 2018 Author Share Posted October 5, 2018 I've done that already, not with a pressure washer though. Link to comment Share on other sites More sharing options...
27donb Posted October 5, 2018 Share Posted October 5, 2018 1 hour ago, B.Liesberg said: I've done that already, not with a pressure washer though. And after you did, how did the water jacket look? Was it as clean and clear as the pic Gary posted? Link to comment Share on other sites More sharing options...
fraso Posted October 5, 2018 Share Posted October 5, 2018 (edited) 17 hours ago, B.Liesberg said: I'm still having overheating troubles in traffic, I cleaned out the cooling system and have fresh coolant. Engines overheat because there is insufficient heat transfer from the engine to the air flowing through the radiator. In your case, does overheating mean boiling over and spewing coolant or just running at higher than normal temperature? 17 hours ago, B.Liesberg said: The thermostat currently in the engine is a standard 160 degree. I have a spare 160 hi-flow, would it be better to install that one or would that cause the coolant to flow through the radiator too fast? The thermostat's job is to maintain a minimum temperature. The heat transfer capability of the cooling system determines how much hotter the engine runs over the thermostat's opening temperature. Increasing the flow of the heat transfer fluids (coolant and air) increases heat transfer. Increasing the temperature difference between the 2 fluids also increases heat transfer so if an engine does not overheat with a 160° thermostat, it certainly won't with a 195° thermostat. I would do an acid (citric or oxalic) flush of your cooling system, which will remove more rust and scale than a mechanical cleaning. Although rust and scale on the engine's interior cooling system surfaces will not cause your engine to overheat, they will reduce heat transfer into the cooling system, which could make your engine more susceptible to engine knock for example. See Cooling System. Edited October 5, 2018 by fraso (see edit history) 1 Link to comment Share on other sites More sharing options...
DonMicheletti Posted October 5, 2018 Share Posted October 5, 2018 Since the block is clean, then the thermostat and radiator become suspect. With all the original components in good condition the engine will not run hot. However, a long time ago I had a crazy issue with my '38 Roadmaster. I had had the waterpump rebuilt. After a couple of months of running fine with no temperature issues, the engine suddenly began overheating. I suspected a bad thermostat - but it was OK. Since the car had been running OK I was stumped. It drove me crazy. As a last resort, I removed and opened up the water pump - expecting maybe a bad impeller. Turned out the impeller was loose on the shaft. Once that was fixed, all was back to normal. That was a real longshot. I had never heard of that before. I was surprised the the pump did not leak. Link to comment Share on other sites More sharing options...
B.Liesberg Posted October 5, 2018 Author Share Posted October 5, 2018 7 hours ago, 27donb said: And after you did, how did the water jacket look? Was it as clean and clear as the pic Gary posted? Honestly it looked pretty close to that when I opened it, I think someone else had gone through the system previously. But I cleaned it anyways. 1 hour ago, fraso said: Engines overheat because there is insufficient heat transfer from the engine to the air flowing through the radiator. In your case, does overheating mean boiling over and spewing coolant or just running at higher than normal temperature? It boils over. 1 hour ago, fraso said: The thermostat's job is to maintain a minimum temperature. The heat transfer capability of the cooling system determines how much hotter the engine runs over the thermostat's opening temperature. Increasing the flow of the heat transfer fluids (coolant and air) increases heat transfer. Increasing the temperature difference between the 2 fluids also increases heat transfer so if an engine does not overheat with a 160° thermostat, it certainly won't with a 195° thermostat. I am aware of this, that's why I asked about a hi-flow thermostat and not a lower temp opening thermostat. I don't know if the coolant will be running through the system too quickly with a hi-flow or if the larger engine prefers it. I can try the acid cleaning too just to see what happens. I think part of my issue too might be timing &/or mixture. I have a friend coming over this morning with his engine analyzer to help me get the engine tuned up properly. Link to comment Share on other sites More sharing options...
Gary W Posted October 5, 2018 Share Posted October 5, 2018 Timing is huge! If you're running on a "late" spark, she'll heat up for sure. In some of my cars, if they are running too lean, they'll also run hotter than if the mixture is adjusted properly. 1 Link to comment Share on other sites More sharing options...
B.Liesberg Posted October 5, 2018 Author Share Posted October 5, 2018 19 minutes ago, Gary W said: Timing is huge! If you're running on a "late" spark, she'll heat up for sure. In some of my cars, if they are running too lean, they'll also run hotter than if the mixture is adjusted properly. That's why I'm working on it. Link to comment Share on other sites More sharing options...
27donb Posted October 5, 2018 Share Posted October 5, 2018 (edited) 33 minutes ago, Gary W said: Timing is huge! If you're running on a "late" spark, she'll heat up for sure. In some of my cars, if they are running too lean, they'll also run hotter than if the mixture is adjusted properly. So true, I left the spark retarded at idle to warm up my engine on a cold morning and left it there for too long, and it started to boil over. Also, are you using 100% water, or water/antifreeze mix? Too much antifreeze can cause boil over too. Ask me how I know... ? Edited October 5, 2018 by 27donb (see edit history) Link to comment Share on other sites More sharing options...
B.Liesberg Posted October 5, 2018 Author Share Posted October 5, 2018 Roughly 60-70% water. Link to comment Share on other sites More sharing options...
JRHaelig Posted October 5, 2018 Share Posted October 5, 2018 Going back to the radiator - you could be in my situation where I had a pretty cool running engine, but then did a "clean while you drive" operation using low suds dishwasher detergent. THEN the overheating started. I can only surmise that I got myself a nice clean block, but all the crud I loosened went into the radiator. Out it came, off to the shop and came back working just fine. Any chance you did the same thing? Link to comment Share on other sites More sharing options...
fraso Posted October 5, 2018 Share Posted October 5, 2018 3 hours ago, B.Liesberg said: It boils over. That helps to understand the severity of the issue. 3 hours ago, B.Liesberg said: I am aware of this, that's why I asked about a hi-flow thermostat and not a lower temp opening thermostat. I don't know if the coolant will be running through the system too quickly with a hi-flow or if the larger engine prefers it. Higher flow will help but, if you're overheating while idling in traffic, your water pump isn't moving very much coolant. With heat transfer, more flow is better. Don't confuse the rad's coolant outlet temperature with the heat removed from the engine. A thermostat is typically fully open 15-20°F above its rated temperature. In your case, it should be wide open by 180°F so switching to a 195°F (fully open by 215°F) would make no difference. 3 hours ago, B.Liesberg said: I think part of my issue too might be timing &/or mixture. I have a friend coming over this morning with his engine analyzer to help me get the engine tuned up properly. It's always best to have your engine tuned properly. 4 hours ago, B.Liesberg said: I can try the acid cleaning too just to see what happens. If it's still overheating after the tune-up, then do the acid flush. Citric and oxalic acid are safe for iron, brass, and aluminum and work better when hot. Sometimes it takes several flushes to get your engine clean. I've ran citric acid flushes for several days at time in my engine with no adverse affect. Link to comment Share on other sites More sharing options...
40-Torpedo Posted October 5, 2018 Share Posted October 5, 2018 If you remove a thermostat - it also serves as a restriction which is needed for proper heat transfer. In all the race cars that have the thermostat removed, a restrictor is installed (usually just a fender washer) to slow the rate of flow so that proper heat transfer can occur. Just a thing to consider when removing a thermostat.... 2 Link to comment Share on other sites More sharing options...
fraso Posted October 12, 2018 Share Posted October 12, 2018 On 10/5/2018 at 6:27 PM, 40-Torpedo said: If you remove a thermostat - it also serves as a restriction which is needed for proper heat transfer. In all the race cars that have the thermostat removed, a restrictor is installed (usually just a fender washer) to slow the rate of flow so that proper heat transfer can occur. Just a thing to consider when removing a thermostat.... Water-to-Air heat exchangers all follow the same rules. Removing the thermostat will cause the engine to run too cold so a flow restrictor allows the engine to run at a higher temperature. Again, don't confuse the rad's coolant outlet temperature with the heat removed from the engine. B.Liesberg: Any updates about your overheating situation? 1 Link to comment Share on other sites More sharing options...
B.Liesberg Posted October 13, 2018 Author Share Posted October 13, 2018 Yes, it seems to have calmed down a bit, although I don't know if the problem is completely gone yet. I am considering rebuilding the engine now anyways though, I really didn't want to, but due to it running poorly I think that it may be my only choice. Link to comment Share on other sites More sharing options...
fraso Posted October 13, 2018 Share Posted October 13, 2018 I would not rebuild the engine until I was positive that it was worn out. Do you have poor compression or oil pressure? Link to comment Share on other sites More sharing options...
B.Liesberg Posted October 13, 2018 Author Share Posted October 13, 2018 Poor compression. It also misfires a lot at idle. There was a lot of sludge in the engine when I purchased the car, I think it was helping plug up some of the gaps. When I flushed the oil system I think I removed a lot of it leading to the engine running crummy. It still drives ok, but I would rather not drive it excessively if there is a lot of wear and risk damaging it more severely. Link to comment Share on other sites More sharing options...
Guest Posted October 13, 2018 Share Posted October 13, 2018 On 10/4/2018 at 5:33 PM, DonMicheletti said: It is a lot of work, but a big part of the solution is to knock out all the core plugs and clean the crud out of the water jacket This is the only way to clean the water jacket out. Sixty years ago if a straight eight Buick came in to the dealership where I worked it was an automatic core plug replacement with mechanical removal of the crud. If the owner wouldn't let us do that he was told to take his overheating problem somewhere else. We had pails of rust, scales and crud to dispose of and never had a come back. Link to comment Share on other sites More sharing options...
MCHinson Posted October 13, 2018 Share Posted October 13, 2018 On 10/4/2018 at 3:50 PM, B.Liesberg said: I'm still having overheating troubles in traffic, I cleaned out the cooling system and have fresh coolant. The thermostat currently in the engine is a standard 160 degree. I have a spare 160 hi-flow, would it be better to install that one or would that cause the coolant to flow through the radiator too fast? What do you know about the condition of the Bypass Valve? If it is not working properly, you will have an overheating problem even if everything else is fine. Link to comment Share on other sites More sharing options...
BuicksBuicks Posted October 13, 2018 Share Posted October 13, 2018 Two things that I have noted. Vaporust works very well if used according to the label instructions. In my case I ran my severely plugged cooling system at high idle for three hours; I don't know if leaving it in the system for a week with some driving will achieve the same result. Another jug of Vaporust is a cheap investment compared to an engine rebuild. Also, an engine rebuild will do nothing if the radiator is plugged. The second item concerns the driving conditions when overheating. Is it overheating primarily in summer traffic? That's pretty much common and the solution there is to avoid congested traffic and high speed interstates. Link to comment Share on other sites More sharing options...
Spinneyhill Posted October 13, 2018 Share Posted October 13, 2018 (edited) It seems to me you have several problems. Poor compression. Compression readings and leak down test results? Vacuum gauge test results? Running poorly. Tune-up? -timing, plug gaps, points gap and perhaps new points, make sure the spark plug wires are not arcing somewhere (look at it running in the dark). After all the electrical ignition setup is done, look at the mixture settings. Overheating. Clean block already (but acid and evaporust flushes don't necessarily remove hardened, encrusted rust at the back of the back cylinder very well - I have just been through this with my Dodge 8); we don't know about the radiator or the water pump or the bypass. Buy a cheap IR thermometer and take the temperature of the radiator all over it. Mine was blocked and that part was significantly cooler. Overheating is not a reason for a rebuild, yet. It is really a system separate from the reciprocating engine parts. P.S. The radiator shop demonstrated my blockage by wetting the radiator then filling it with boiling water. The blocked part stayed wet longer than the rest of it. It was blocked in a triangular shape reaching up from the bottom. Edited October 13, 2018 by Spinneyhill (see edit history) Link to comment Share on other sites More sharing options...
Guest Posted October 13, 2018 Share Posted October 13, 2018 1 hour ago, Spinneyhill said: Overheating. Clean block already (but acid and evaporust flushes don't necessarily remove hardened, encrusted rust at the back of the back cylinder very well - I have just been through this with my Dodge 8); we don't know about the radiator or the water pump or the bypass. Buy a cheap IR thermometer and take the temperature of the radiator all over it. Mine was blocked and that part was significantly cooler. Ir thermometer is a wonderful investment. I wish I had bought one years ago. Link to comment Share on other sites More sharing options...
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