So... I'm pretty stoked to finally have the '51 not overheating and able to go on cruises farther than the corner store. The only question I have now is if my temp is common. I see some guys post that they get over 200* all day and no problems but others say it should never get over 180*-190* So far I have: replaced thermo, water pump, rodded radiator, replaced head gasket... after all that she still over heated real quick but then I realized that after the last time I worked on her I was running no thermo... So, I put a new one in and she stopped over heating (another topic of debate I saw on here as far as no thermo vs thermo). So after a little cruise she did good at 185*-190* and then, got up to 200*... After going further she got up to 210*-220* .... But never overflowed , steamed or gave any signs of overheating. Now, for me I was happy considering I never was able to ride before without overheating and I mean steam hissing and boiling over. With all this said, I just wanted some opinions on what you think about this... I know some guys say it's cool and some don't but I just wanted to get some new thoughts. Thanks, Larry P.S. I will check to make sure the timing is on point.
Have you stuck a thermometer in the radiator to see exactly what temp the motor is getting to,you might have cooked the sending unit and its not reading correctly now.
Whether it is 105 or 20 outside my old 235 hangs right around 160. I have never got it any hotter, in traffic, working it, whatever, its the coolest running engine I have ever had.
The 235 in my 37 p/u gets no hotter then 185 according to the NOS gauge,that is flying down the road or sitting in traffic. What year 235 do you have in it,if you have a 55 to 62 motor with the shortened water pump with the 216 size pulley I have heard about them running to hot since the pump is spinning too fast. I had that style pump in my 37 when I first put it togather but had no problems but I do have a 4 row radiator,the temp gauge did not work at that time and it never blew any coolant out but after running hard I did hear some gurgling sound coming from the radiator when shutting off which has not done again after getting the adapter to mount a 54 on back pump on the later 235.
I don't like when the coolant goes to 190 - 200 degrees or more. Aside from correct timing, etc...most important are good air and coolant flow, of course. Not hard to to determine if it has good airflow...no debris in the rad fins, no bent over or flattened fins, good fan and maybe shroud that helps rather than hinders airflow, etc. To determine good coolant flow, I like to leave the radiator cap off and run the engine until it's hot enough to have opened the thermostat. Then use a light, and with the engine still running, look down the filler neck. You should see a "torrential river" of coolant movement. If you don't, then flow is being restricted for some reason. More often than not, it's the radiator. Even though you had the radiator "rodded", I'd still test it for good fast flow. With the radiator full and cool, remove the cap. Then remove the lower hose. Take note of how fast the radiator emties. It should empty in no more than 2, 3, 4 seconds...like right now. Another gremlin to coolant flow, is when we forget to include an inside spring in the lower hose. After warm-up, the hose can collapse from the vacuum produced by the water pump. Another common, sometimes almost undetectable problem. When the water pump bearing starts to go bad, it'll let just a little water out at a time. But it's difficult to see the leak, 'cause it's not a lot, and it steams off immediately from the heat of the engine. Not only does this lower the level of coolant, but also keeps the system from working as designed. As a sealed system, it works as a pressure cooker does...allowing the liquid to reach a higher temperature without boiling. If the cooling system leaks, there's no pressure to keep it from percolating. The sounds you heard when the engine was hot is probably percolation, which might indicate a leak. Good luck. Post updates.
The radiator in it now is the original radiator that came in the '51 but the motor in the car is a 235 I6 that came out of a '56 pickup... This is a new gauge so I am assuming it is reading correctly but I find it funny that it is not boiling over at that temp. I also forgot to mention I added a 19" fan the other day. Now, even though the radiator was just taken to a professional radiator shop and rodded/cleaned the amount of flow is not really that visible. I mean I can see a little movement. I have heard from a few old timers that those specific radiators you don't see much flow but then again, from others I hear you are supposed to see a lot of flow. I can't imagine running at 160* ... Man, that must be nice, it is at that temp pretty much a few blocks out the driveway. Still in all I'm happy she is doing good I'm just trying to get to the bottom of this and get everything the way it should be. I'm so close LOL Thanks guys and keep em coming, I'm all ears. Larry
I bought an Infrared tempurature gun (for lack of better name) from Amazon.com. It was about $30.00 including shipping. It's been a real handy tool. I used it to trouble-shoot the cooling system of the flathead in my '51 Ford (which all of a sudden started running at about 120 on the gauge). It turned out to be the single pole temp sending unit was bad. It was real interesting to "shoot" the different parts of the engine and actually see what they are running at. It was of particular interest to see the difference between the temp at the top of the radiator vs that at the bottom. It's also handy around the house; found out the oven was running 30 degrees cooler than the temp it was set at. Also used it to "shoot" each of the exhaust pipes on my vintage race car to ensure all cylinders were doing their job.
Just thinkin'...see if we hit on somethin'. You said not a lot of coolant movement in the radiator, and it rises in temperature quickly. Assuming the gage is correct...maybe it's not...determine that first. Otherwise, sounds like a lack of coolant flow. Maybe an obstruction/restriction somewhere. Got a spring in the lower hose? Then I'd start by checking how quickly the radiator empties. If it's good, I'd check flow through the engine and pump. Maybe backflush.
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