Temperature Guage Kit

jeandeau · #1 (**permalink**) 01-17-2009, 05:49 AM

I propose to assemble digital thermometer kits that are easy to install and use high quality components. Includes: LM35 teperature sensor, JB Weld epoxy putty, wiring harnesses with connectors soldered and insulated, 12V connection which plugs into fuse box and grouds on support bolt, display module w printed circuit board, circuitry complete, 3 digit Blue LED display and LED which flashes at selected temperature. Bargraph optional, multicolor and flashes at over-temperature. I am open to suggestions. I'll go ahead if I have ten commitments. estimated cost $35. Sorry I don't know how to build a poll atachment

kylerwho · #2 (**permalink**) 01-17-2009, 05:58 AM

what temperature are you trying to read? water temp? oil temp? outside temp?

jeandeau · #3 (**permalink**) 01-18-2009, 03:02 AM

Most of us will place the sensor on the back of the block, just below the head, for an accurate measurement of engine temperature. I'm happy to supply extra sensors and a selector switch and indicator arrangement to monitor as many temperatures as you choose. I used a set of four to compare effectiveness of aftermarket vs factory Automatic transmission coolers. The sensors are contained in a package the size and shape of a transistor which can be epoxied to most surfaces and covered with insulative foil backed tape.

No_Skillz · #4 (**permalink**) 01-19-2009, 05:36 PM

So these will be reading the temperature of the aluminum of the head at the location that it's taped on?

jeandeau · #5 (**permalink**) 01-19-2009, 08:51 PM

Precisely. If you ever had an engine failure due to coolant loss, you would appreciate that choice. When the cooling system is working fine, The engine temperature is similar from the bottom of the block to most of the cylinder head. If something goes wrong, the combustion area will see it first and the sensor sees it last. A sensor in the coolant will sometimes not see the change at all! Changes of engine load affect the cylinder head, exhaust passages and block temperature faster and to a greater degree than they affect the coolant. It is really the temperature of the head casting and the cylinder walls that concern us most. Heat conduction in aluminum is very good and a sensor bonded to the block just below the head has an excellent path of conduction across the top of the block. The cylinder head is insulated from the block by the cylinder head gasket. Coolant keeps block and head temperatures similar. A sensor on the head close to the exhaust may be useful but this is a tricky installation. On the Honda Fit, there is a horizontal reinforcing block web behind cylinder #1 just below the exhaust manifold. This is an easy installation point close to the top of the engine block, protected from wind, easily insulated from air temperature and exhaust heat. I see small changes due to changing load and speed with this setup, and if there ever should be a failure, I want to hear it directly, not from a sensor connected to a puddle of piss on the road 5 miles behind me.

manxman · #6 (**permalink**) 01-19-2009, 09:48 PM

I am very interested in the concept. Considering the multiple readings available from a
ScanGauge, and since your device concerns temperature readings only, in addition to block and transmission temps, would it be possible to add sensors and switchable readouts for ambient interior and exterior air temps? Many people lament the lack of air temp readings in the cabin. If these "frivolous" extra readings would complicate the manufacturing to the point of raising the cost too high, I would still be interested in engine/trans measurements.

Thanks, "John Doe".

jeandeau · #7 (**permalink**) 01-19-2009, 10:26 PM

On my temperature gauge suggestion, additional temperatures are easily obtained and viewed one at a time, cycled through by touching one button. Cost on the circuit board is negligible. If I design my own circuit board, it will certainly have multiple inputs with an input selector. Sensors cost about $3 each plus the wiring.
At $179, I highly recommend the Scangauge for what it does and does very well. It has it's limitations though such as only coolant and intake air temperatures.

*Garismatic* · #8 (**permalink**) 01-22-2009, 10:14 PM

Definitely interested... In fact, if it were 8+ channels, I would likely do shock temps, possibly front knuckle(wheel bearing) temps. Just because I'm curious

jeandeau · #9 (**permalink**) 02-03-2009, 06:45 PM

I installed a mini thermometer (shown right) and illustrated installation of the larger Scythe thermometer. I have photos of wiring on flickr <kurtlittlewood> I see the photos are not visible in the post so maybe someone can tell me if I'm doing something wrong or I lack a permission perhaps.

robcollins5 · #10 (**permalink**) 03-10-2009, 02:02 PM

I'll purchase immediately. Please PM me with contact info.

Thanks!

rc

jagass · #11 (**permalink**) 03-10-2009, 02:41 PM

What type of temp gauge are you trying to say?...Be specific please...

jeandeau · #12 (**permalink**) 03-11-2009, 08:54 AM

Primarily we are discussing engine temperature, a digital LCD display, Blue backlit display when ignition is on, black numbers on grey background when ignition is off. Read posts #3 to #6. pictures are posted on flickr.com (search honda thermometer) including installations. My email is engineer@icrossroads.com. I was unable to PM reply. Perhaps I don't know how. It seems we now have to have skype or America Online Instant Messaging to make a reply in the forum. I hesitate to install even more applications on my computer but maybe i'll have to.