sherwood3333 Posted January 7, 2018 Share Posted January 7, 2018 can some one tell me is a rebuilt motor is supposed to be broken in hot or cool temp. what is the best thermostat to use thanks Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted January 7, 2018 Share Posted January 7, 2018 I would use nothing less than a 180*. Any time, any thing. The thermostat has nothing to do with the MAX temp, only the LOWESTl Ben Link to comment Share on other sites More sharing options...
NTX5467 Posted January 7, 2018 Share Posted January 7, 2018 As the particular block casting is well-cured from many hot/cold cycles, the machine work done should now be "solid" and clearances not moving when compared to a "green" new casting (which a new car would have). I concur with the 180 degree thermostat. On a "fresh start-up", you want the engine to start and run immediately and get to operating temp somewhat quickly for general principles. In that orientation, treating the engine/trans as "lumber", where you let it sit in the same general temp area that it will be nailed to, might be advisable this time of year. The builder might have put some pre-lube on the cam and lifters, but removing the distributor and using a pre-lube shaft to run the oil pump before start-up is advisable. Rather than using that existing (and possibly draining-down) prelube as the primary initial lubrication. Adjust the ignition timing so it maintains the desired 3000rpm for several minutes after initial fire-up. Oil slung off of the crankshaft is what oils the cam lobes. After it runs a while, then vary the rpm up and down a little, to get oil slung into different areas at the various rpm levels. After about 30 minutes total run time, then you can start lowering the rpm until you slowly reach base idle, where the final timing and carb adjustments will take place. Make sure the area is well-ventilated and the vehicle exhaust exits the building. Recheck the fluid levels and look for leaks. Re-tweak the carb adjustments after a few hundred miles. Check the fluid levels, too. Please advise of your progress. Enjoy! NTX5467 Link to comment Share on other sites More sharing options...
retiredmechanic74 Posted January 7, 2018 Share Posted January 7, 2018 If I might add something I've learned through all the years I've rebuilt engines is for the first 500 mile do not hold the engine at an even speed fluctuate the speed take it up t 70 mph but don't hold it there. After 500 miles re-torque the heads and intake. I think you will find the engine will be much faster. Link to comment Share on other sites More sharing options...
sherwood3333 Posted January 8, 2018 Author Share Posted January 8, 2018 ok thanks, rebuilt motor starts up great, motor was rebuilt and pre lube was used on engine parts, installed 180 thermostat, not registered yet so cant drive on open road I just ran the motor for a short time revving the motor slightly, will fine tune carb next 3 Link to comment Share on other sites More sharing options...
avgwarhawk Posted January 8, 2018 Share Posted January 8, 2018 The 180 stat will help with a more complete burn in the cylinders. 1 Link to comment Share on other sites More sharing options...
NTX5467 Posted January 9, 2018 Share Posted January 9, 2018 I was looking around the other night at AMA specs and it seems that several '50s cars used the 160 degree thermostat back then. Made me wonder if that was "a fix" for needing a bigger or better radiator in the car? I remember people talking about air flow around the motor with regard to how hot they ran, back then. But as with the '56 Buicks, if the dash gauge was calibrated for "straight up" being 160 degrees, then using a 180 would make it read higher, getting closer to the marked "red zone". So, when you get the car legally on the road, you might use an infrared non-contact thermometer to calibrate the temp gauge compared to thermostat housing temperature. Let us know how it turns out. NTX5467 1 Link to comment Share on other sites More sharing options...
KongaMan Posted January 9, 2018 Share Posted January 9, 2018 My dad used to have a 57 Buick wagon that ran hot. If I remember the story correctly, Buick's "solution" to the problem was to recalibrate the gauge the following year. Link to comment Share on other sites More sharing options...
Bloo Posted January 9, 2018 Share Posted January 9, 2018 A 160 degree thermostat isn't going to help you much with cooling. On some level it actually hurts. The limit on how much you can cool is usually the the size of the radiator opening and the amount of air you can funnel through it. You can add more layers to the radiator, but once you get to three layers, adding a fourth doesn't really do much, other than add space for a little more coolant, which is good, but probably doesn't justify the expense. Cooling is also limited by difference between the temperature of the air flowing through the radiator, and the coolant in the radiator. If the coolant is hotter in temperature, the radiator can remove more actual heat from the engine, because there is a bigger difference in temperature at the radiator. a 160 degree thermostat gives you a little more "headroom", a little more time to see that the temp is rising, but at the expense of actual cooling efficiency. None of this matters that much once you get close or exceed the limits of the cooling system. The system will run hotter. The thermostat only sets the lower limit. I would consider running a 160 degree thermostat if it were original equipment for the car. It cant hurt if it is part of the original design. 180 degrees will get you a lot better heater. If there is some question whether an engine runs too hot, just temporarily put a real mechanical gauge on it. Recalibrating the factory gauge isn't crazy if it reads hot and the engine is actually running at the thermostat temperature. 160 degree thermostats only exist because of alcohol-based antifreeze. It is below the boiling point of the alcohol. Does anyone still use this? 1 Link to comment Share on other sites More sharing options...
Beemon Posted January 9, 2018 Share Posted January 9, 2018 I Just want to add that recalibrating the gauges is not as easy as everyone makes it out to be. To do it right you need to establish what temp is min and max, or perhaps where you want normal to be. Then you need a good known thermometer, a high quality controlled hot plate and a beaker. These gauges are also really fragile and you have to be careful not to damage the brass. The hardest part is of course removing it from the dash and hoping you do not break the bulb pulling it through the firewall as you carefully unwind it. You could theoretically do it on the stove top, but it is not a very good controlled environment and is prone to error. Ask me how I know... both my oil pressure gauge and temp gauge worked flawlessly until I removed them from the dash... 1 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted January 9, 2018 Share Posted January 9, 2018 (edited) 7 hours ago, KongaMan said: My dad used to have a 57 Buick wagon that ran hot. If I remember the story correctly, Buick's "solution" to the problem was to recalibrate the gauge the following year. I believe it. There was a time were putting temp numbers on the gauge created more worry than what it was worth. Drivers would see the temp at 180 degrees Monday and Tuesday 185 degrees, etc. They would bring in the car for overheating issue that was not there. Eventually they decided to just print COLD, HOT and NORMAL on the gauge. As long as the driver sees the needle in the NORMAL range all was well. Keep in mind the needle can fluctuate in the NORMAL range but to the driver see it is in this range so all was well. Edited January 9, 2018 by avgwarhawk (see edit history) 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted January 9, 2018 Share Posted January 9, 2018 6 hours ago, Bloo said: A 160 degree thermostat isn't going to help you much with cooling. On some level it actually hurts. The limit on how much you can cool is usually the the size of the radiator opening and the amount of air you can funnel through it. You can add more layers to the radiator, but once you get to three layers, adding a fourth doesn't really do much, other than add space for a little more coolant, which is good, but probably doesn't justify the expense. Cooling is also limited by difference between the temperature of the air flowing through the radiator, and the coolant in the radiator. If the coolant is hotter in temperature, the radiator can remove more actual heat from the engine, because there is a bigger difference in temperature at the radiator. a 160 degree thermostat gives you a little more "headroom", a little more time to see that the temp is rising, but at the expense of actual cooling efficiency. None of this matters that much once you get close or exceed the limits of the cooling system. The system will run hotter. The thermostat only sets the lower limit. I would consider running a 160 degree thermostat if it were original equipment for the car. It cant hurt if it is part of the original design. 180 degrees will get you a lot better heater. If there is some question whether an engine runs too hot, just temporarily put a real mechanical gauge on it. Recalibrating the factory gauge isn't crazy if it reads hot and the engine is actually running at the thermostat temperature. 160 degree thermostats only exist because of alcohol-based antifreeze. It is below the boiling point of the alcohol. Does anyone still use this? Running a 160 in my 264 did not allow the engine to get to temp and run efficiently. Specifically in the winter. Needle never got off the COLD mark. Heat was lacking. Needle on the gauge never held with any consistency. I went to a 180 after replacing the heads. Quite a difference. Needle held steady once warm. Including driving it hard at 70 mph on a very not summer day. 1 Link to comment Share on other sites More sharing options...
Bloo Posted January 9, 2018 Share Posted January 9, 2018 3 hours ago, avgwarhawk said: I believe it. There was a time were putting temp numbers on the gauge created more worry than what it was worth. Drivers would see the temp at 180 degrees Monday and Tuesday 185 degrees, etc. They would bring in the car for overheating issue that was not there. Eventually they decided to just print COLD, HOT and NORMAL on the gauge. As long as the driver sees the needle in the NORMAL range all was well. Keep in mind the needle can fluctuate in the NORMAL range but to the driver see it is in this range so all was well. Very true. One thing I am gonna throw out there is that back in the day, every clued-in driver knew "where the needle ran" on the particular car he/she drove every day. There was not necessarily any expectation that it be in the center of the gauge. It varied from car to car and most people regarded that as normal. 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted January 9, 2018 Share Posted January 9, 2018 2 hours ago, Bloo said: Very true. One thing I am gonna throw out there is that back in the day, every clued-in driver knew "where the needle ran" on the particular car he/she drove every day. There was not necessarily any expectation that it be in the center of the gauge. It varied from car to car and most people regarded that as normal. Then came the idiot lights. Let me tell you about the idiot light. My 78 Regal running a 231 odd fire had the overheating idiot light illuminate exactly at the same time steam came pour out of the hood from a blown radiator. The engine was so hot it burned both valves on #1 cylinder. Never trusted the idiot lights from then on. Link to comment Share on other sites More sharing options...
sherwood3333 Posted January 11, 2018 Author Share Posted January 11, 2018 thanks for the feed back, I have been told by some old motor heads that buicks ran hot back in the days this is why I wanted some feed back, thanks Link to comment Share on other sites More sharing options...
buick man Posted January 17, 2018 Share Posted January 17, 2018 Curious … why should one assume that to be true and what would the " designed - in " rational be for having Buicks running hot back in the day … ? True the dynaflow in the very early straight eights tended to run a little on the warm side and did over heat under strenuous conditions however it was found to be from a lack of proper trans cooling and that was addressed, so by the time the nailhead came into service it's cooling capacity was much different and improved and the dynaflow had improved fluid flow capacities as well … We believe where a lot of these stories came from is through bad radiator / coolant maintenance and quality of coolants used rather than engineering and capacity issues … For what it's worth and most relevant to this post, any of the 3 other 57 Buicks I have owned in the past any heating problems were from clogged radiators, choked corroded internal blocks and or bad water pumps. But with that said and also for good measure attempt to separate the dynaflow trans cooling from the engine cooling system via an external front thick diesel pickup truck type mounted trans cooler and see how that works for you 2 Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted January 17, 2018 Share Posted January 17, 2018 I agree. I have NEVER had a Buick, or anything else, that overheated or "ran hot" if the radiator was in good clean shape. Right now, my 1950 Special with a warmed up larger bored 263, using the original radiator that has been re cored, runs normal even with added AC. In 95 degree Texas heat. Ben 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now