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Posted by: Geezer914 Jan 13 2021, 03:53 PM

VDO no longer makes them, any other gauges out there?

Posted by: BeatNavy Jan 13 2021, 04:20 PM

Oh yeah. At least a few of us use this one:

https://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=347/mode=prod/prd347.htm

Posted by: barefoot Jan 13 2021, 05:01 PM

Here's mine
https://www.ebay.com/itm/Digital-DC-Temperature-Meter-for-J-type-Thermocouple-12V-Fahrenheit/172101324800

And matching TC's
https://www.ebay.com/itm/J-Type-Thermocouple-with-14mm-id-Washer-for-Cylinder-Head-Temperature-CHT/172302303136

Cold junction compensated and works quite well

Posted by: Olympic 914 Jan 13 2021, 05:26 PM

They also have a nice matching digital oil temp gauge.

Posted by: 930cabman Jan 13 2021, 05:56 PM

I just ordered a new set of VDO gauges, oil temp, oil pressure, clock and voltmeter from Summit and also found out they are no longer making a cyl head temp gauge. Nuts. I was hoping to fill the console with a 5 gauge cluster. Off to plan B

Posted by: jeffdon Jan 13 2021, 07:01 PM

I got mine from https://www.aircraftspruce.com/

They have one that looks super close to VDO gauges, plus they are temperature compensated. VDO are not,

Posted by: Mark Henry Jan 13 2021, 09:36 PM

I have a micro1000 from Aircraft Spruce, the small round CHT is real close fit with the aftermarket VDO cockpit gauges.
Con is the numbers are a bit small... but if the needle stays straight up (300F) I'm golden.
Pretty sure it's the same one as Jeff's.

Posted by: Charles Freeborn Jan 14 2021, 01:03 AM

http://thesensorconnection.com/category/cht-sensors/all-cht-sensors

Posted by: Geezer914 Jan 14 2021, 08:35 AM

Thanks for the replies, went with a Dakota Digital.

Posted by: mate914 Jan 14 2021, 09:32 AM

If I may ask? Which spark plug do you install CHT probe on? I would like to know for both the six and four cylinders.
Thank you.

Posted by: Mark Henry Jan 14 2021, 09:57 AM

/4 the #3 cylinder runs the hottest.

/6 it doesn't matter as much, some say #1, some say #6....I used #1 just because it's the easiest to run to.

Edit: For the /6 the #1 cylinder is the easiest for me to get to as I'm twin plug and I have a lift. I have my sensor on the lower #1 plug hole.
On a standard 6 plug engine the 4/5/6 side may be easier to get to.
This is important because you must take care not to twist or cut wires on plug install. On my six I cut/notched the plug hole seal for the CHT sensor wires.

Posted by: veltror Jan 14 2021, 03:55 PM

https://kaefertuer.com/produkt/zylinderkopf-temperatur-ueberwachung-zkt-stage-1-1-12-volt/

Posted by: 930cabman Jan 14 2021, 04:12 PM

Just read your rustoration thread, heroic to say the least. Keep the faith and hopefully soon your 914 will be rolling down the road.

Posted by: pete000 Jan 14 2021, 06:23 PM

I have a NOS MIB VDO CHT stashed away...

Posted by: FlacaProductions Jan 14 2021, 06:30 PM

LOL - NOS MIB VDO CHT.

Very cool but not temperature compensated, is it?
Maybe not a big deal but nice not to have to do math in public.

Posted by: 930cabman Jan 14 2021, 07:15 PM

Can someone educate me with regards to "temperature compensated"
thank you

Posted by: davesprinkle Jan 14 2021, 08:10 PM

There are various types of temperature sensors. The kind called a "thermocouple" uses a very specific alloy of wire. Accurately measuring temperature with one of these sensors requires that the measurement circuit know the temperature at the point that this alloy is connected to copper. (This is misleadingly called the "cold-junction" temperature.) Cheap devices omit this cold-junction temp measurement and are less accurate as a result.

Posted by: FlacaProductions Jan 14 2021, 09:07 PM

as i understand it - and i could be wrong - non-temperature compensated gauges will read out higher as the ambient temperature goes up and lower as it goes down. ie: if your engine temp is (for example) 250 at 72 degrees, a non-compensated display will show 260 at 82.

temp-compensated will show 250 no matter the ambient temp.

Posted by: Highland Jan 14 2021, 10:15 PM

I think Ratwell has a pretty good explanation:

https://www.ratwell.com/technical/VDOGauges.html#cht

It almost seems VDO assumed if your head temps got high the engine compartment temperatures would also be high so they compensated with the scale.

I have a VDO gauge and still trying to figure out how to interpret the information based on the outside air temperature that day. Any recommendations would be appreciated.

Posted by: aharder Jan 14 2021, 10:29 PM

I had a VDO for years and then it failed. I ended up with this one and I've been
pleased with it so far.
https://discountegauges.com/deg-cylinder-head-temperature-kit-part-310-901-12-12ft/

Posted by: barefoot Jan 15 2021, 10:06 AM

Not true, sorry.

Thermocouple based cylinder head temperature gauges use a bimetal construction that generates a voltage if one end is heated (or cooled). Thermocoulpes will measure the temperature DIFFERENCE between the hot end and the other end. Cold junction compensation introduces a measurement at the cold end then does an addition to read the actual temperature at the hot end, not just the difference.
i verified mine by placing the hot end in ~ boiling water as a bench test and got 210 degrees. Cooled to room temperature and the gauge read 73, so i know I'm reading actual head temps.
Hope this helps

Posted by: narino Jan 15 2021, 03:44 PM

Aharder - This gauge is nice! Looks a lot like the micro1000 from Aircraft Spruce that Jeff and Mark Henry posted. Does it take any 14mm TC? Or is it a specific connection?

Anyone know if the square bezel on the micro1000 can be removed to leave a circular gauge?

Posted by: 930cabman Jan 15 2021, 05:28 PM

Agreed, I will be lining up for this one. Thanks for posting

Posted by: FlacaProductions Jan 15 2021, 07:01 PM

Perfect, thank you and my apologies.
One thing I hate is when untrue/wrong information is spread here and I hate that I'm part of doing so. Thanks for setting me - and the record - straight.

Posted by: Krieger Aug 1 2022, 04:40 PM

@http://www.914world.com/bbs2/index.php?showuser=697 Henry did you need to make any modifications to the sensor to get it to fit on your six?