1936 120 Overheating
Posted by hollidayjd On 2016/9/10 15:17:34
I realize some of this topic has been discussed previously, but would like to post this and make sure I have covered all of the possible solutions.
Background: I started the restoration 18 years ago. Block was cooked and flushed, all new bearings, pistons, etc. were installed. Radiator was cooked, flushed and pressure checked. It was not re-cored at that time. Engine was run twice for about 3 hours each time over several years until last November, then run again with no problems. Note: radiator had 50/50 antifreeze/water mix in it for years while being stored.
Car finally assembled this spring and summer. Engine was running with no problems, but had a carburetor issue. Carb repaired and run again..... within 15-20 minutes it overheated while driving it back and forth in the driveway.
Continues to overheat.
What I have done: water pump removed and inspected, radiator and block drained. Radiator flushed using water from garden hose and captured. Only very tiny rust particles present and not very much of those. Pretty clean. New 50/50 antifreeze installed (note: Packard specs state 18 quarts in system - I could only get 14-1/2 quarts in it). Heater valve (on top of head) and block drain plug opened to remove air pockets. Air came out of heater valve, but just steady stream of coolant out of drain plug. Heat riser valve in exhaust manifold tested - works properly. Using a laser temperature device when running the car at idle, radiator temperature differential between top and bottom is approximately 40 to 50 degrees (cooler at the bottom of course).
Temperature gauge needle gets to 212 degrees, but laser devise shows a little less at probe entry point. Gauge was not rebuilt because it worked when I tested it. After shutting engine down, in a few (15-30) seconds or so it "burps" coolant from the overflow tube. There are no detectable leaks in the radiator or anywhere else. Not a head gasket issue - oil looked good, but was changed again along with coolant. Has anyone rebuilt their engine, then had this issue due to close tolerances of new parts (bearings, rings, etc.) which builds up heat in the block? I don't believe the rings have seated yet because this motor has not been run "under load" - by driving it. Any advice would be greatly appreciated. I have waited a long time to get this thing done, now I am stymied with the overheating. Daryl
Forgot one thing: does anyone know what the "normal" operating temperature is (say at 70 degrees ambient)?
A couple of pictures.
Attach file:
(375.00 KB)
(387.80 KB)
(302.40 KB)
Background: I started the restoration 18 years ago. Block was cooked and flushed, all new bearings, pistons, etc. were installed. Radiator was cooked, flushed and pressure checked. It was not re-cored at that time. Engine was run twice for about 3 hours each time over several years until last November, then run again with no problems. Note: radiator had 50/50 antifreeze/water mix in it for years while being stored.
Car finally assembled this spring and summer. Engine was running with no problems, but had a carburetor issue. Carb repaired and run again..... within 15-20 minutes it overheated while driving it back and forth in the driveway.
Continues to overheat.
What I have done: water pump removed and inspected, radiator and block drained. Radiator flushed using water from garden hose and captured. Only very tiny rust particles present and not very much of those. Pretty clean. New 50/50 antifreeze installed (note: Packard specs state 18 quarts in system - I could only get 14-1/2 quarts in it). Heater valve (on top of head) and block drain plug opened to remove air pockets. Air came out of heater valve, but just steady stream of coolant out of drain plug. Heat riser valve in exhaust manifold tested - works properly. Using a laser temperature device when running the car at idle, radiator temperature differential between top and bottom is approximately 40 to 50 degrees (cooler at the bottom of course).
Temperature gauge needle gets to 212 degrees, but laser devise shows a little less at probe entry point. Gauge was not rebuilt because it worked when I tested it. After shutting engine down, in a few (15-30) seconds or so it "burps" coolant from the overflow tube. There are no detectable leaks in the radiator or anywhere else. Not a head gasket issue - oil looked good, but was changed again along with coolant. Has anyone rebuilt their engine, then had this issue due to close tolerances of new parts (bearings, rings, etc.) which builds up heat in the block? I don't believe the rings have seated yet because this motor has not been run "under load" - by driving it. Any advice would be greatly appreciated. I have waited a long time to get this thing done, now I am stymied with the overheating. Daryl
Forgot one thing: does anyone know what the "normal" operating temperature is (say at 70 degrees ambient)?
A couple of pictures.
Attach file:
(375.00 KB)
(387.80 KB)
(302.40 KB)
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