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temp Gauge

1K views 8 replies 4 participants last post by  LBL 
#1 ·
I switched out my 6 cyl in my 59 Ranchwagon with a 351W and I am using the stock gauge in the dash. I also installed an electric fan and the thermostat is a 200 - 185. The needle on the gauge goes a lot higher with the 351 than it did with the 6 and I was wondering if it is actually running hotter, or if the signal it is getting would be different with the different engine? So my question is, do different sensors send different signals or should they all read the same ? Thanks...
 
#2 ·
lots

Lots of things to consider.

A---Engine coolant thermostat will modulate (control) at it's rating, say it's 185*. There will be a calibration error of at least 5% +/-.

B---The fans control thermostat needs to be rated higher than (A) by at least 10* because it will have a turn ON and a turn OFF temp. rating. Say 195* ON and 185* OFF.

C---The gauge sensor needs to located near the (A) . This is needed because the coolant temps in the engine vary. And the gauge will have a calibration error of 10% +/-.

So the if gauge reads 10* more that you would like it's probably as close as it will get. But if it's 30* high---see above.

vicrod
 
#4 ·
Okay

I'll clarify what I have as I didn't do a very good job in the initial post. The Thermostat in the engine is a 195. The thermostat that controls the fan for the rad comes on at 200 and cuts out at 185. The gauge doesn't have graduations on it, it just shows "C" on the left side and "H" on the right side. With the old 6, the needle used to sit about 2/3 of the way across but now it sits on the "H". I can't put the original sensor in from the 6 because I sold the engine plus it was a different size. Maybe I will get an infrared temp. gauge and shoot the thermostat housing when it is running to see what the temp of the motor really is .
 
#5 ·
kcblueoval

You may need to remove the thermostat heat gauge sending unit from the 6 cyl. engine & install it in the 351 V-8. The V-8 may run hotter than the 6 cyl. but the sending unit and the gauge will match up. If the the sending unit is not available you should be able to pick up a new sending unit from the parts store that will match the car V-8 or 6 should not matter. Good Luck.
 
#8 ·
So long as the original sender is smaller than the hole in the 351 manifold, its fine to use a bushing to adapt it. If its larger, you need to find a smaller sender with the same resistance per degree profile. A temp sender needs to be in the flow of coolant, so you can't just stack a bunch of adapters to expand out to a larger sender.
 
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