Coolant temp sender idea

[mattcrp1]

Hi all, I have been trying to figure a way to install my factory temp sender for the dash in my '76 with out being to intrusive. I tried to turn down a sender and cut threads into it and the sender was to thin. I don't want to drill and tap the head or the water pump, but I remembered that some ford products had a temp sender/switch in the heater hose like this one pictured. I figured I could cut the tube, flare the end and install it in line. Anyone have pro/con's about going this way?

Thanks,

Matt

[LockDoc]

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I think you would have to make sure the resistance of the sender matches the gauge...... Not sure on the newer stuff.

LockDoc

[mattcrp1]

I was planning on installing the factory '76 sender and adding a ground to the sender as it would be insulated by the rubber. Do you think it would be accurate enough in relation to engine temp if I mounted it on the heater outlet side of the engine?

Thanks

[LockDoc]

Originally Posted by mattcrp1

I was planning on installing the factory '76 sender and adding a ground to the sender as it would be insulated by the rubber. Do you think it would be accurate enough in relation to engine temp if I mounted it on the heater outlet side of the engine?

Thanks

I don't have a clue on that. I think I would want it in the head. I drilled and tapped the head on mine to 1/2" NPT so I could use the stock '67-'72 gauge style sender.

LockDoc

[Super73]

It will read differently in the head. Heck, I have the factory one in the drivers head (front of cyl #1) and it reads different than the autometer one installed in the passenger head (behind #8). At first I thought the gauge was off until I pulled the sender and hooked it up in a pot of water. Verified it was correct.

My buddy with a 67 LS1 has his set up the same way I do. He sees the same issue.

About 10% difference for both of us. IE the passenger rear is 10% hotter than the drivers front.

[LockDoc]

Originally Posted by Super73

It will read differently in the head. Heck, I have the factory one in the drivers head (front of cyl #1) and it reads different than the autometer one installed in the passenger head (behind #8). At first I thought the gauge was off until I pulled the sender and hooked it up in a pot of water. Verified it was correct.

My buddy with a 67 LS1 has his set up the same way I do. He sees the same issue.

About 10% difference for both of us. IE the passenger rear is 10% hotter than the drivers front.

I have read that having it at #8 will give you the most accurate reading of the actual engine temp.

LockDoc

[Super73]

That's why it is hooked to my gauge not the computer. I can look at it on the track.

[mattcrp1]

Originally Posted by Super73

It will read differently in the head. Heck, I have the factory one in the drivers head (front of cyl #1) and it reads different than the autometer one installed in the passenger head (behind #8). At first I thought the gauge was off until I pulled the sender and hooked it up in a pot of water. Verified it was correct.

My buddy with a 67 LS1 has his set up the same way I do. He sees the same issue.

About 10% difference for both of us. IE the passenger rear is 10% hotter than the drivers front.

That's a great point/observation, I figured it would be some what off from the original position in the rear of the head but did not realize the 10% it would make.

[mattcrp1]

After trying to cut down a stock sender ( the one on the right) to put in the rear position in the passenger head, I got a couple of brass pieces to put it in line with the outlet to the heater core.

[mattcrp1]

I added a ground wire to the brass "T". I figured as long as it can give me an indication of where I am temp wise it should be close enough.

[solidaxel]

What pieces are inside the stock sender. I think I lost one when I turned it down, all I have is the spring.

[chuckmc8]

Originally Posted by LockDoc

I don't have a clue on that. I think I would want it in the head. I drilled and tapped the head on mine to 1/2" NPT so I could use the stock '67-'72 gauge style sender.

LockDoc

Leon, How difficult was it to drill and tap the head for the stock 67-72 sender? I thought about doing that but frankly, I'm scared of screwing up the head

[tbrown5079]

Made a sleeve for mine in the top radiator hose and ran a ground wire. One side has the temp sender, the other side the fan sensor.
tbrown

[mattcrp1]

Well I got it mounted in line and filled the cooling system. I forgot to fill the upper hose when I lit it off and ran it for a minute. I realized that the hose was not getting warm and shut it off and filled the hose. The hose got warm immediately and seem to be working fine so far.