Temperature sensors

[Iceni John]

Technomadia's trials and tribulations with their engine has got me seriously thinking about how my engine's coolant temperature gauge works.   I recently moved it to front and center of my instrument cluster  -  to me, it's the most critical gauge of all.   My understanding is that DDEC sensors are entirely separate from the gauges' senders, so does this mean there are two temperature senders already, one for DDEC and one for the gauge?   Am I correct?

I would like to have two sensors for the gauge and two for the DDEC, one for each bank for each application.   Is this feasible?   If so, can both senders just feed together, or do they have to kept separate.   Obviously I want whichever sender gets hotter to override the other.   Where should senders ideally be located  -  the thermostat housings, the heads, where?

Sorry for all these questions  -  I just want to have as much warning as possible if something's beginning to go bad.   For this reason I've also installed a brake application force dual pressure gauge (to tell me if my brakes are fading, or if there's a leak in either system), and I'm now putting in a turbo boost gauge (to know if the turbo's showing signs of failure).   I just don't want surprises down the road!

Thanks, John  

[Rick 74 MC-8]

John

I would look at installing a low coolant sender or possibly a coolant psi gauge.  Temperature senders will not show a over heating problem if the collant level is low enough to have the sender not exposed to coolant

Rick

[Iceni John]

I do already have a low coolant sensor in my radiator header tank that is part of the DDEC safety shutdown system.   DDEC will stop the engine for three reasons  -  low coolant level, low oil pressure and high coolant temperature.   I'm thinking more along the lines of getting early warning before DDEC shuts me down.   What concerns me is that if my temperature sensor is on one bank, and the other bank is beginning to overheat, I may not know about it until something bad has happened.

I've looked for dual temperature gauges, something similar to my dual air pressure gauge, but I've not found anything so far.   I don't want, and don't have space for, two temperature gauges, nor do I want to have to manually toggle between two senders on one gauge.

Maybe I'm being overly neurotic about this stuff, but Technomadia's problems may be only a few degrees of coolant temperature away from any of us.   My radiator is already iffy (the bottom right corner of it is cooler than the rest of it, so that's something else to take care of), plus who knows what other lurking issues there could be.   Forewarned is forearmed!

Thanks, John

[Len Silva]

Eagles had two temperature gauges, I'm sure others do as well.  Here is one that might work for you.

http://www.genosgarage.com/WESTACH-2-UNIVERSAL-DUAL-TEMP-GAUGE-CHOOSE-2-SENSORS/productinfo/WM-DUALTP/

[Lee Bradley]

John,
The senors should be in the head.  My 8-92 has the temp and DDEC senors on the passenger side and the other head has no holes on that end of the engine. Apparently the
factory only cast/drilled one end of the head so I will be installing the other senor on the opposite end of the engine. Remember that end of the engine will run a little cooler.

Len,
Thanks for the link; saved me a lot of time looking for that gauge.  Looks like the pyro in my race car.

Lee

[Iceni John]

Lee, thanks for confirming what I was thinking, that the sensors should be where any overheating is most critical, i.e. the heads.   I'll look at my engine today and see where any usable ports are in the heads  -  I guess they aren't too different than yours for sensor locations.

Len, yes, that's sort of what I had in mind.   I was thinking more of a 270-degree single-sweep with two concentric needles (like my brake force gauge), but that dual-sweep gauge is OK, even though I think it's butt-ugly!   I do like that it has 200 F right in the middle, just where things get interesting for a 2-stroke.   $145 ain't cheap, but the consequences of overheating ain't cheap either . . .

Thanks for this good info,
John

[Len Silva]

If you don't have room for two separate gauges, the options are limited.  In addition to gauges, I like the idea of alarmstats that kick in well before shutdown.

I find that as I get older, scanning the gauges as I once did, doesn't always happen.