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Tagged: Overheating
I am having overheating problems with my 1929 Model 133 Straight 8 overheating. Does anyone know of anyone in the Houston Texas area that can work on Pierce Arrows?
Edward,
There is going to be an article on troubleshooting overheating in the next issue of the Service Bulletin. I can e-mail that article to you now if it will help you. Sorry, I don’t know of anyone in your area that works on Pierce-Arrows.
Dave
Thanks Dave. Do you have my email or should I send it to you?
I’ll get it off your member record.
Hi, Edward:
A couple questions come to mind with the overheating…
-What’s the condition of the connection between the generator to the water pump?
-Has the water jacket cover ever been removed, and the inner water box inspected, or replaced? Has the water jacket/block been cleaned…and the radiator in recent memory?
-What does your lower radiator hose look like? Is it reinforced so that it doesn’t collapse?
-Thermostat functioning OK? A temp gun can be helpful, here.
-Any recent adjustments to the carburetor. Is it running lean?
-Changes in the timing?
Not trying to throw darts blindly, here, but maybe one of these will help you locate the source of the issue.
Good Luck!
-Carl
Carl is on the right path. I would start with the temperature gun, to see if the issue is more in the engine or radiator. Take a reading at the radiator outlet, then the neck of the upper hose as it leaves the block. Compare the temperature rise across the block, then the temperature fall across the radiator. All the heat from the engine is dissapated by the radiator, but at what temperatures?
The inlet to the radiator will match the engine exit temperature. The fan and airflow will cool the water going through it. If the radiator exit to still hot after driving or is losing water out the overflow, the radiator becomes the first suspect. Even at reduced flow from a collapsed hose, the radiator will reject as much heat it can and its exit temperature should be OK unless something has fouled the inside sutface. Idling or slow parades can cause a heat up as there is no wind across the radiator.
If the water leaving the radiator is cool, it is likely not that it is the source of the problem. If the water entering the engine is cool enough then something is either reducing flow thru the engine side or producing more heat. The temperature sensor is near the back of the head and basically measuring water outlet temperature, which makes it fairly accurate.
There are four major engine side low restriction sources: collapsed pump intake hose; low water level; thermostat not fully open; and rust/gunk clogging the water passages of the engine. If the hose has collapsed, you may hear rattling noises in the pump using a stethoscope (cavitation). Water level is easy to check. Thermostat in the engine exit and water jacket require opening and checking. Do the easy ones first.
The other set of problems comes from too much heat generated by the engine. Lean fuel mixture can cause this issue. Good Luck. Herb
Thank you both for the info.
I am running a straight water system with No-Rosion as the rust inhibitor. I was substantially low on water. There are no leaks, so I am guessing that I had substantial evaporation.
Both mentioned that I could be running lean. How do I diagnose this?
Ed
Ed,
The easiest way to check mixture is to look at a spark plug. I usually drive the car and pull over, shut it off and pull a plug after it cools a little. The plug tip insulator should be light tan. White indicates too lean, black too rich. See: https://blackhawkparamotor.com/wp-content/uploads/2020/01/Spark-Plug-Color-For-Paramotor-Engines.pdf
Doing a web search for ” How to check mixture by reading a spark plug” will give you all kinds of information.
Another option is to get a tailpipe “sniffer”.
Dave