Engine Instrumentation Project - Page 6 - PeachParts Mercedes-Benz Forum

funola · #76 07-14-2015, 09:09 PM

Your results are to be expected. To get actual oil sump temperature, the sensor has to be in direct contact with the oil. I would suggest drilling the drain plug with a through hole and epoxy the sensor in place extending 1" into the oil.

mach4 · #77 07-14-2015, 11:16 PM

Quote:

Originally Posted by funola

Your results are to be expected. To get actual oil sump temperature, the sensor has to be in direct contact with the oil. I would suggest drilling the drain plug with a through hole and epoxy the sensor in place extending 1" into the oil.

It still wouldn't be in direct contact with the oil... the sensor chip is encased in a plastic or ceramic package and that is encased within a metal sheath and possibly in some epoxy as well. So I guess I'm just screwed. I'll just ignore the actual reading and focus just on the relative readings.

funola · #78 07-15-2015, 05:13 PM

Quote:

Originally Posted by mach4

It still wouldn't be in direct contact with the oil... the sensor chip is encased in a plastic or ceramic package and that is encased within a metal sheath and possibly in some epoxy as well. So I guess I'm just screwed. I'll just ignore the actual reading and focus just on the relative readings.

I said the sensor must be in direct contact with the oil, not the sensor chip, which is always encased in a thin metal shroud to protect it.

Look at the coolant temp sensors and switches, they are placed deep into the coolant. The way you have the sensor halfway in the oil drain plug, it could never reach equilibrium with the oil, temperature wise because the oil pan and drain plug is being cooled by ambient air.

If you think you are measuring actual oil temp, then you need to investigate why it is so low.

mach4 · #79 07-20-2015, 04:29 PM

Quote:

Originally Posted by funola

If you think you are measuring actual oil temp, then you need to investigate why it is so low.

I'm convinced that the temperature I'm indicating is the actual temp, within a fraction of a degree. It's a snug fit to the oil drain plug and it's into the plug 90%. I think the only thing I could do to get a better reading is add some heat-sink paste to the probe.

But your point of low temperature reading is beginning to look like a valid concern. I had kind of expected to see ambient temp plus about 15 like I see with the probe on the Arduino and then a rapid increase in temps once the thermostat opened and hot oil went to the cooler when I had the probe mounted on the cooler line, but it didn't. It just rose steadily until it got to 150 or so, and higher temps of 180 or so when pulling up a hill on a warm day.

It appears that the thermostats can be replaced, though not terribly easily. I'm wondering if anyone has done so recently.

The other thing I'm wondering is how many people are potentially driving around with thermostats stuck open and never know it because they have no oil temp gauge. Or vice versa, with high oil temps because the thermostat is stuck closed and the cooler is never brought into play.

crazy4diesel · #80 07-21-2015, 02:46 PM

Very cool instrumentation project!

I'm curious too about the air intake changes, and valve cover breather you've set up here. Did you do another thread on that project?

mach4 · #81 07-21-2015, 03:44 PM

Quote:

Originally Posted by crazy4diesel

I'm curious too about the air intake changes, and valve cover breather you've set up here. Did you do another thread on that project?

Yes, here - Built a Catch Can

marybeth · #82 07-24-2015, 11:14 PM

Awesome project.

Two questions
#1-What do you estimate you spent in $$$
#2 -Consider selling the whole thing as a kit (minus the display)-sensors, box, etc?

I would purchase two

mach4 · #83 07-24-2015, 11:54 PM

Quote:

Originally Posted by marybeth

Awesome project.

Two questions
#1-What do you estimate you spent in $$$
#2 -Consider selling the whole thing as a kit (minus the display)-sensors, box, etc?

I would purchase two

#1 The tablet was $60. The Arduino, power supply, Bluetooth module, breadboard, headers, etc was about $25. Temp sensors were about $2 each, boost and vac sensors were JY items (MAP sensor), fuel pressure sensor was $20 and EGT sensor and amp was $25. Sensor mount materials was about $7.

#2 No

marybeth · #84 07-25-2015, 10:39 AM

Mach your KILLING ME-I must GOTTA have that on my current transplant conversion.

I'll pay cash for a clone

Pretty Please!

mach4 · #85 07-25-2015, 11:48 AM

Quote:

Originally Posted by marybeth

Mach your KILLING ME-I must GOTTA have that on my current transplant conversion.

I'll pay cash for a clone

Pretty Please!

I'm flattered, but I know what's required and there are just too many variables and too much time is involved. I might be convinced to share the Arduino code and discuss in greater detail the strategy and devices I used...but even that would take some doing. It works, but it's not pretty - virtually anyone with coding experience and electronics background could do far better.

mach4 · #86 10-16-2015, 02:32 PM

I'm in the middle of a project to move my engine instrumentation system from the existing prototype/breadboard configuration I used as a proof of concept, to an actual PCB board. At the point I get the design done and a prototype built and tested it would be trivial to order additional boards in quantity for those that would like to assemble, program and install their own EDMS-II (Engine Data Monitoring System II).

As I've said before I have no interest in putting together an actual product because of the countless variables and hassles of support, but a DIY project with pointers and a basic discussion on how to integrate the hardware and modify the code could be doable.

The second version EDMS-II), as currently conceived, would include the additional functionality of a micro-SD card for data logging as well as two extra analog sensor inputs for user expansion.

To create a working system a user would need to be able to:

- source various circuit components - Arduino nano, buck, thermocouple amp, bluetooth, micro-SD, resistors
- solder components to PCB
- mount in project box and install in engine compartment
- source and integrate sensors for temp, fuel pressure, EGT, boost and vacuum etc.
- fabricate sensor mounting brackets
- wire sensors to Arduino
- install Arduino IDE to PC, modify code, upload code to Arduino
- install Processing Language IDE and Android extensions to PC
- source suitable Android tablet
- configure PC-Android connection
- modify code to fit screen, edit screen images and upload to tablet
- install tablet in vehicle as desired

I'd simplify the software to only provide one or two digital display screens making it easy to adapt to different tablets for those unfamiliar with coding. I'd also take time to comment and clean up the Android and Arduino code to make it easier to understand what's happening. I'd also envision a forum for users to share extensions and solutions to their particular installations, such as additional display screens and installation solutions.

Anyone interested? I'm asking now because it's a little different making a board for just me to use and one that others will be using and whether to actually start cleaning up code.

A rough cost breakdown would look something like -

EDMS-II PCB - $30-50
k-Thermocouple - $12-30
MAX31855 breakout - $20-30
1 bar MAP - $1-20
3 bar MAP - $1-40
fuel pressure sensor - $20-35
temp sensors - $2-5 ea
tablet with bluetooth - $30-200
resistors - $1-4
power supply - $4-10
HC-05 bluetooth - $10-20
MicroSD - $ 5-10
project box and connectors - $10-25
tablet power source - $5-15

This is not a trivial project. Each sensor poses unique engineering challenges. For example EGT requires drilling and tapping exhaust manifold or turbo inlet pipe. Oil temp could involve drilling oil drain plug or fabricating a clamp on the oil cooler line - and so forth. A virtually unlimited number of temp sensors can be used without hardware modification.