Temperature Update !! ??

[Deleted User]

I got the Pacemaker out today and warmed her up in the driveway. This is at the fast-idle speed she was set at. After running for about 15 minutes and after seeing the temp gauge climb to the 3/4 mark, lower to the 1/2 then slowly rise back to the 3/4 mark....I tested the external temperature at many points using a laser IR thermometer (+/- 3% accuracy).

Thermostat Housing - 160 to 165, read on several points
Top Rad tank - 170 to 175, on several points
Head at Temp Sensor - 185
Block under Temp Sensor - 160
Head between cylinders (not Siamesed points) - 175 to 180
Coolant Return Line (steel tube in between rubber hoses) - 123

So, I think I have a decently running engine now. I will be adding a resister in-line so that at idle and warmed up, my gauge reads 1/2.

RonS

What year is your car? In 1951 the temp & fuel gauges used a voltage drop behind the dash cluster . If this is defective, the readings will be adversly affected. Is your fuel gauge accurate?

[Deleted User]

Mine is '50. The fuel gauge does not work (not connected at the moment - but does function when 6v and resistance is applied).

BTW, a 10-Ohm resistor did very little to the reading other than slow it down. At idle for 20 minutes, I was back up to 3/4 on the gauge with temp readings basically the same as above.

[Deleted User]

I would think that if the temp is 185 at the temp sensor, then the guage at 3/4 is probably about right. What does a cooking thermometer in the rad neck read, "Beef medium" ?

[Deleted User]

rbennett47: Funny!!!!

On a serious note...how does one get the overall temp lower if all the other readings are within reason and a good indication that the engine is within range but on the higher end?

lostmind

You are not running hot. The gauge shows 3/4 at idle. Most Hudsons I had showed the same at idle.When you are at cruise speeds it should show just above 1/2.
I had a temp gauge installed under the dash of my 49 and it read 170 degrees while the dash gauge showed just over half.
I think you have a normal reading for a Huson.

Club Coupe

Lostmind is absolutely correct. I have owned a 1951 Pacemaker for over 40 years and if I let it idle or sit in traffic the gauge will go up to nearly 3/4. it goes down as it is driven. It has always done this and it is normal for any car. At speed the gauge will stay around 1/2. Prior to the new gasoline blends, it ran a little below 1/2. You have no problem as long as you don't see steam rising over the hood, no matter what the gauge reads and in 40 years, no matter what my gauge has read I've never seen any steam and I don't think that you will either.

[Deleted User]

OK. Thank you. I just wanted to make sure I had everything covered. My Mother-In-Law told me that her Daddy always had trouble with it overheating. Once I identified the errant headbolt, I think I have it solved.

I am so used to my modern cars that show barely half in 95 degree, heavy traffic.

[Deleted User]

Actually, when I got my '54 it had a 12" electric fan mounted on the right front side of the radiator, and it really makes a difference in traffic on hot days. We've had it on while in quite heavy city traffic, on 100+ degree days, and, while it got warm, it never did boil over. It seems to draw around 15 amps, but is quite effective. I know they're out there, new and used, but they can't be too much, and we just switch ours manually with an in-line fuse....Just an idea if you're concerned about stop-and-go driving.

RonS

PM500, New cars run at way higher temps in the 205 area. If the gauge goes above its usual point, that will be a caution sign... over 3/4 point & your cooking. If the temp gauge to HOT you have about 30 seconds to either shut down( and pray) or eject. Result of more that a few seconds will result in, at least, a warped head or blown gasket. New aluminum engines are not as heat tolerant as old cast iron ones. They are fragile, if all works well, are lighter more efficent and more powerful. That is why there are so many warning lamps and chimes keeping the operator abreast of conditions. As was said by the guys before, your 50 is performing as expected. One thing, 1950 was the first year for a pressure cap ( 7# ). Does your car have the correct cap?

[Deleted User]

Yes, I have the correct 7# cap.

Glad to hear I am operating as should be.

THANK YOU ALL for your help, instruction, gentle guidance and patience. Next is the Over Drive Unit.

Geoff

Rule of thumb - if it doesn't use water or produce steam it doesn't matter much what temperature it runs at.

DocHornet

PM500, New cars run at way higher temps in the 205 area. If the gauge goes above its usual point, that will be a caution sign... over 3/4 point & your cooking. If the temp gauge to HOT you have about 30 seconds to either shut down( and pray) or eject. Result of more that a few seconds will result in, at least, a warped head or blown gasket

Ron, with all due respect, I couldn't disagree more with your "30 second warning" assessment. Here in sub-tropical Texas, I have at least 4 older cars ('59 Jaguar, '59 MGA, '40 Cadillac, '39 Ford) that routinely exceed 200, even 212 F temperatures every summer for extended periods of time, and have never had any engine issues as a result. Do I like it? No.. but it's just a fact of life here in the South.

Most knowledgeable guys will tell you that as long as water doesn't overflow from the cap, you'll be just fine. Ever wonder why newer cars don't have actual temperature numbers on the gauge? It's because they are designed to routinely operate at normal temperatures well in excess of boiling.

Ironically, my '51 Hornet has need had overheating issues, even in traffic with the A/C running full blast. I do, of course, have an auxiliary electric fan, and newer radiator.

RonS

Doc, I was refering to new cars such as 21st century aluminum blocks. Old cars as you mentioned are cast iron( I'm not sure of the Jag), And as Geoff said, as long as the water is not boiling creating air bubbles there isn't too much worry about precise temps. My 289 "68 Ford ran 205 and even 210 when the AC was on at idle in AZ. No problem

SuperDave

Just for the heck of it.. I cranked up my two 49's. one is a 262 six with 12 volts and no alterations to the guage, just running the original guage on 12 volts. the other one is an 8 with the original 6 volt pos gnd, (earth as they say down under) I let them warm up, drove around our Block ..about 2 1/4 miles. Both registered about 3/4 on the guage. A thermometer inserted in the radiator read 180 degrees on both. Both have 170 degree thermostats. Ambient temp was about 89 fh. So 3/4 is just fine. If it aint boilin' don't worry.