Head Temp |
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Head Temp |
hedfurst |
Feb 23 2018, 09:25 AM
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#1
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Member Group: Members Posts: 99 Joined: 9-March 03 From: S. Mississippi Member No.: 406 |
Rebuilding a track-car I haven't used for 10 years, it has 2 VDO head temp gauges and was set up for #s 1 and 3. I'd like to be able to watch all four.
Has anybody ever set any thing up for this before? I'd like a switch to change from 1 & 3 to 2 & 4? |
brant |
Feb 23 2018, 09:52 AM
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#2
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914 Wizard Group: Members Posts: 11,617 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
Rebuilding a track-car I haven't used for 10 years, it has 2 VDO head temp gauges and was set up for #s 1 and 3. I'd like to be able to watch all four. Has anybody ever set any thing up for this before? I'd like a switch to change from 1 & 3 to 2 & 4? a lot of people have done it check the air craft suppliers for the gauges like that spruce is one... but you probably would be better off monitoring EGT on each cylinder than 4x- headtemps..... the EGT is going to be more money but more useful I think a single CHT on #3 is adequate if you know your mixture and your EGT brant |
hedfurst |
Feb 23 2018, 10:39 AM
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#3
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Member Group: Members Posts: 99 Joined: 9-March 03 From: S. Mississippi Member No.: 406 |
Rebuilding a track-car I haven't used for 10 years, it has 2 VDO head temp gauges and was set up for #s 1 and 3. I'd like to be able to watch all four. Has anybody ever set any thing up for this before? I'd like a switch to change from 1 & 3 to 2 & 4? a lot of people have done it check the air craft suppliers for the gauges like that spruce is one... but you probably would be better off monitoring EGT on each cylinder than 4x- headtemps..... the EGT is going to be more money but more useful I think a single CHT on #3 is adequate if you know your mixture and your EGT brant Hey, appreciate it but what I was wondering was if there was a way to rig up a switch for an extra two sending units to use the gauges I have! |
brant |
Feb 23 2018, 11:56 AM
Post
#4
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914 Wizard Group: Members Posts: 11,617 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
Rebuilding a track-car I haven't used for 10 years, it has 2 VDO head temp gauges and was set up for #s 1 and 3. I'd like to be able to watch all four. Has anybody ever set any thing up for this before? I'd like a switch to change from 1 & 3 to 2 & 4? a lot of people have done it check the air craft suppliers for the gauges like that spruce is one... but you probably would be better off monitoring EGT on each cylinder than 4x- headtemps..... the EGT is going to be more money but more useful I think a single CHT on #3 is adequate if you know your mixture and your EGT brant Hey, appreciate it but what I was wondering was if there was a way to rig up a switch for an extra two sending units to use the gauges I have! probably.... but why.. again CHT on #3 is going to tell you the whole story and you can't use CHT to judge mixture EGT will not only tell you mixture but will give you real time info about what is going to happen to head temps before there is a problem much better info info available to prevent a problem plus perfect mixture and max performance not sure there is a benefit what so ever to adding 4 CHT readings. I don't even run CHT on my race car at all I use innovate wide band O2 for mixture but in order to cut weight no CHT what so ever Attached image(s) |
jd74914 |
Feb 23 2018, 01:43 PM
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#5
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Its alive Group: Members Posts: 4,780 Joined: 16-February 04 From: CT Member No.: 1,659 Region Association: North East States |
Hey, appreciate it but what I was wondering was if there was a way to rig up a switch for an extra two sending units to use the gauges I have! Just buy a thermocouple selector switch. (IMG:style_emoticons/default/smile.gif) Cheap surplus one with 4 channels: https://obtainsurplus.com/electrical/compon...917024jj17store |
jd74914 |
Feb 23 2018, 01:53 PM
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#6
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Its alive Group: Members Posts: 4,780 Joined: 16-February 04 From: CT Member No.: 1,659 Region Association: North East States |
The less costly and more space saving way is to buy any double-pole, double-throw (DPDT) switch and wire each side of the TC to it's respective pole.
CAVEAT: IF YOU GO THIS WAY YOU NEED THE SWITCH TO BE NEAR THE GAUGE. The reason is that by using a generic switch (without special Nickel-Chromium amd Nickel-Alumel wires, assuming you're using Type K), you introduce cold junction error which puts a bias on your measurement. As long as the switch and your gauge are at the same temperature you're good to go because the compensation is the same. (IMG:style_emoticons/default/smile.gif) See the picture for a wiring example. For some reason you need to click on it, it's not displaying all of the test otherwise. Attached thumbnail(s) |
hedfurst |
Feb 23 2018, 04:26 PM
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#7
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Member Group: Members Posts: 99 Joined: 9-March 03 From: S. Mississippi Member No.: 406 |
Thanks to you all! Appreciate your expertise.
Obviously some things to think about. |
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