Cylinder Head Temp Sensor? Options

[Puebloswatcop]

Is a cylinder head temp sensor needed on a carburated car? It seems it is just for the "computer" on an FI car, but I need to clarify.

[914Sixer]

NOT required

[Puebloswatcop]

NOT required

Thanks,

Didn't think so, but wanted some expert confirmation

[930cabman]

The cyl head sensor is not required for the engine to run, but it's information. I will be running one on the build I am currently working on. It could be helpful if your carbs are getting on the lean side.

[Dave_Darling]

Note that the stock CHT sensor is not the same type as those used by the CHT gauges. It's also in an area of the head that changes fairly slowly. It's not a good data source for telling you much of anything about the engine.

Use the ring-type thermocouple around the spark plug which is the standard way to get CHT readings.

--DD

[930cabman]

Note that the stock CHT sensor is not the same type as those used by the CHT gauges. It's also in an area of the head that changes fairly slowly. It's not a good data source for telling you much of anything about the engine.

Use the ring-type thermocouple around the spark plug which is the standard way to get CHT readings.

--DD

(IMG:style_emoticons/default/headbang.gif)
Thank you Dave, I have also read the same, under the spark plug is the most accurate location for cyl head temp. Can this be problematic when changing spark plugs? I can see the ring getting lost when threading a new plug into the head

[BeatNavy]

The ring is attached to a long wire that leads to your display. So no, the ring shouldn't be at risk of getting lost. At least that's how it is on my Dakota Digital setup.

Putting it on the plug and then getting the plug in the head can be slightly tricky, particularly if the head hasn't had any material removed to allow the room for the ring/wire so they can sit flat aginst the head. On one set of heads I used a dremel to cut away some relief. I think the AAA heads now are cast with a relief already there.

[VaccaRabite]

Note that the stock CHT sensor is not the same type as those used by the CHT gauges. It's also in an area of the head that changes fairly slowly. It's not a good data source for telling you much of anything about the engine.

Use the ring-type thermocouple around the spark plug which is the standard way to get CHT readings.

--DD

(IMG:style_emoticons/default/headbang.gif)
Thank you Dave, I have also read the same, under the spark plug is the most accurate location for cyl head temp. Can this be problematic when changing spark plugs? I can see the ring getting lost when threading a new plug into the head

Just grind a little groove into the boss for the wire to exit under the park plug. No big deal.

The first time you put in the plug it will be challenging. But you figure out how to do it and it is easy the rest of the time. You just have to rememeber to remove the washer from the plug you have the temp sender on.

Zach

[stownsen914]

Is it feasible to put the sparkplug ring sensor at the stock CHT sensor location (presumably using a bolt)?

[GregAmy]

Is it feasible to put the sparkplug ring sensor at the stock CHT sensor location (presumably using a bolt)?

You can, but it won't be useful info.

First, that location never gets as hot, or reacts as fast, as under the spark plugs.

Second - and most importantly - given "first" above you will not be able to compare that information to long-standing historical background:

http://www.914world.com/bbs2/index.php?sho...mp;#entry377466

Do it at the CHT if you just want another interesting gauge in the car. But if you want useful info, put it under the spark plug.

GA

[barefoot]

TC mounted under #3 spark plug should be clamped down with something like this :
I made my own. Have changed plugs since, no issues.

[emerygt350]

I just put mine in through the spark plug hole in the tin (cylinder 3, if no one has mentioned it yet) and I am just careful when installing new plugs. Do it the right way if you have the engine out though.

[barefoot]

I just put mine in through the spark plug hole in the tin (cylinder 3, if no one has mentioned it yet) and I am just careful when installing new plugs. Do it the right way if you have the engine out though.

If you didn't put a grommet over the TC wire where it meets the tin it could chafe thru and then you'd likely be reading temperature of the tin itself (IMG:style_emoticons/default/screwy.gif)

[Lockwodo]

Hi all. I want to add a cylinder 3 thermocouple and gauge to my '74 2.0. I brought, but have not yet installed, the setup in the attachment below. Question: I don't like the look of the digital gauge, can someone suggest a traditional needle type temperature gauge that would work with this thermocouple? Something that matches the stock gauges would be great.
Thanks, Doug

 Cylinder_temp_.pdf ( 527.37k ) Number of downloads: 118

[VaccaRabite]

https://www.aircraftspruce.com/menus/in/falcon_cht.html
Pck the one you like.

Make sure it is temp compensated, and uses a ring type thermocouple (I THINK its a K type).

But speaking from experience, the Dakota Digital is THE gauge to have, even though it is a digital readout. Its the one I have in my car, and in my bus, and will have in my dune bug.

Zach

[GregAmy]

Quick side note for you data acq guys/gals.

Sensor Connection $35 K-type thermocouple:

http://thesensorconnection.com/cht-sensors...re-12-and-14-mm

Plus $12 Adafruit amplifier:

https://www.adafruit.com/product/1778

...makes a damned fine input to your system. I'm using it into my Microsquirt ECU for the street car, and into my data acq system on the race car. It's also being used as a failsafe "cut over" for either altermate maps (street car) or "you're being stuipid light" (race car).

If you must have a gauge, I have one of these, with enclosure, sitting in my toolbox I'd be glad to pass along in exchange for a case of your local IPA:

http://thesensorconnection.com/egt-probe-t...egt_meter.shtml

GA