Smokehouse69

I'm preparing to to try and find a replacement for my temperature sensor for my 69 SB, that won't fit in my new Vortec heads. I took the old sensor and suspended it in boiling water and obtained a reading of 2650 Ohms, then I placed in a cup of crushed ice and water (my thermometer said it was 0* C.) the reading was 1150 Ohms.
Has anyone found a new smaller temp sensor that fits anywhere close to this range?
I sure wish that there was someplace that we could get a cross reference for these things!

Larry B.

Do a search on http://www.ncrs.org archives. There is a whole lot of info about calibrating the gauge and various senders.
BTW your heat riser is on the way :cheers:


[Modified by silvervetteman, 6:43 PM 2/3/2002]

427V8

I searched the entire temp sensor catalog at my favorite partshouse. nothing was even close! :mad
I ended up putting the temp sensor in the water neck hole...
The water temp is a little hotter there ( 10 degrees ?) since it's after the heads rather than before it, but it works!

74ZZ430

I'm not sure if my 74 uses the same ohm rating on the temp sender as your 69, but I had the same problem with the fast burn Vortec heads I used. I was never able to find the smaller sending unit with the correct ohm rating. I ended up using a sender with a lower ohm rating and added a in line ceramic resistor that bought my resistance back in line , my gauge is very close now. The ohm ratings the spec books go by are much lower than what you are getting(not sure at what temp. they are taken) if I remember correctly my stock 74 unit was between 78 and 82 ohms and I used a 42 ohm sending unit and added two 20 ohm resistors. I just spliced them into the wire coming from the sending unit and used black wire loom tape to cover them, pretty hard to spot unless your looking for them. I don,t recall the part# of the sender I used but I kept the box, which I can dig out if you need it.

Budman68

Smokehouse,
I'm using an 82 vette sensor and it's pretty darn close. I install a safety back up under the hood and it seems to run inline with it. I have shearched high and low, no one makes a 1/2" sensor with the earlier ohm range.
Budman

KenSny

If the heads are off, just drill out that 3/8 NPT hole with a 23/32" drill and tap with a 1/2-14 NPT. That way hunting for a "close" replacement sensor never comes up again. I did it on my Torquer's driver's side head and left the 3/8 NPT on the passenger side for the electric fan sensor.

Smokehouse69

Thanks for the information guys, I think I'll try several of your suggestions. I wish I had tried to get the heads drilled and tapped before I bolted them on, but worrying about the temp sensor was an afterthought. I'll get a sensor from an 82 'vette, and install a seperate mechanical gauge under the hood. Then I'll put my old sensor up in the water-pump neck. That way I can try switching from the two locations, while it is running.