I've got a simple question for you fellas. I finally got my 51' back on the road and it appears to be running a little bit hot. Coolant level is full, I put a new 160 degree thermostat on yesterday, aluminum radiator, electric cooling fan, and no leaks. I also added a bottle of Water Wetter that definitely helped my Model A run a little cooler. When sitting at a stop light on a 100 degree day my car runs all the way up to 200 degrees and then cools off when the car starts moving again. I'm running a stock 283 with about 65,000 miles on it. Again, it's not losing any coolant. It is definitely running hotter than I want, but how hot is too hot? Also, I just set the timing 8 degrees advanced and it seems to be running great.
On a GM, there's two type of sending units. The older bigger style (60's & 70's) had a different resistance value than the newer style senders & matching gauges. Make sure you got the right one. Also, there's two types of running warm. Warm on the freeway is different than warm in traffic.
Lack of air flow at idle. Try 10-12* initial. 200* dropping back when moving is not too hot. Try a 180 stat a lower temp one does not necessarily equal cooler running. Mechanical or electrical gauge? I have seen mechanical gauges read over 10* off and electrics are like horseshoes close.
I double checked the gauge w/ digital laser. I hate to advance the timing any because it is running so good. 180 degree thermostat might be my next change. Thanks
Verify what temp your electric fan comes on ... your sender might be triggering it a little late. "finally got it running" ... wonder if the block is full of sludge (cooling passages), with only 65,000 miles on it that engine has been sitting a huge part of its life.
You mean you run the electric fan constantly? That is different. Most electric fans run through a sending unit that triggers the fan at a set temp and then shuts it off at a different (lower) temp. If the engine has never been apart and the frost plugs have not been changed you might have a lot of buildup of sludge in the cooling passages. They haven't made 283's for a long time. When I install an engine (used) I always change the timing set and the frost/core plugs. With the plugs out I can inspect and pressure wash all the gunk out of the cooling system.
The fan NOT running and then turning on at 200 would explain what is going on but not if you are running it constantly. Try simple things first ... change to a fresh thermostat.
A friend of mine had an over heating problem and swaped the 160 thermostat for a 180 and that did the trick.
Might remove a frost plug and checkfor sludge. Also get a GOOD 180 degree thermostat some of the parts store specials are junk. I would check and see where the timing is most run well at 8-12 degrees advanced Slow timing can make one run hot.If you check it first you can always put it back.
Better to start at the beginning - define 'too hot'. 200º is definitely running properly, and is indicative of a properly running engine, esp. if it cools slightly when it starts to move. There are reasons that no factory ever put in a 160º thermostat. And OEM engineers get paid to make the cars reliable, economical, and long-lived. Better to follow their example than a 'gut' feeling. Cosmo
Plan of attack: 1. 180 degree thermostat 2. I'm going to run Prestone Flush through engine and flush block w/ water hose Does anyone ever use that Prestone Flush stuff? First, I need to make sure it can be used w/ aluminum radiator.
You probably don't need any special flush stuff, unless it's brown or rusty on the inside. I just keep flushing with water until it comes out clear
Probably hot air recirculating in the engine compartment, nothing beats a good shrouded fan for low speed cooling, the 180 T-stat will help too, keeps coolant in the radiator longer Mark
I've only installed them and left them switched, I use a lighted switch so it reminds me to kill it. Toss on a shroud if what you try doesn't work out. Bob
Nothing is wrong. If it is retaining the coolent the system is performing correctly. Call the radiator manufactur and ask them if you are worried. I still think you ought to drive it like you stole it.
flush. minimize distance fan to radiator. install shroud. check thermostat (cup of hot water works great for that). make sure there's no air bubble under sender. test sender (use cup of hot water again). jimcolwell is right, if your gauge is good and it's not loosing coolant it's working fine, you just need to tweak its working conditions (like distance and air flow)
Temp doesn't sound out of line for Texas in September, but I agree a 180 thermostat would be a good idea. How well is the electric fan shrouded? Many aftermarket ones don't have much of a shroud.
Also ,when installing new 180 degree thermostat if you are concerned about air trapped in system,take a 3/16 drill and drill a hole in the flat surface of the thermostat where it sets in the manifold housing .This allows air to purge out of the system and doesn't bother the thermostat operation at all.
I always drill two 3/16" holes in the thermo as described above and then tap the bypass hole for 1/4" npt and plug it. Old circle track trick.
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