cheap cylinder pressure sensor option - smart diesel glow plug with pressure sensor

[sepp2gl]

Hi Guys,
besides Beru, Sensata and Hidria also Optrand would be a good choice for such a sensor.
A couple of years ago also Bosch and Continental worked on in-cylinder pressure sensors both for diesel engines with integrated glow-plugs and "stand-alone" for gasoline engines. But I don't know, if they discontinued their work.
t2us, sepp2gl

[sepp2gl]

...did anybody continue applying a diesel pressure sensor to a gasoline engine?
Or is this a dead thread?

[Abricos]

...did anybody continue applying a diesel pressure sensor to a gasoline engine?
Or is this a dead thread?

Drama , software,programmers are not interested in this topic ... Yes it dead

[nmstec]

...did anybody continue applying a diesel pressure sensor to a gasoline engine?
Or is this a dead thread?

Drama , software,programmers are not interested in this topic ... Yes it dead

The software, programmers would be false. I would love to continue progress on this. I have done something very basic and similar for TDC locating.

[sepp2gl]

Well...
...the world is definitely not separated in ECU-software and ECU-hardware.
I like to see it Top-Down rather than Bottom-up.
Engine control is multi-domain.
It starts with understanding engine-functionality, combustion-system, thermodynamics.
It continues with the system perspective of engine control, incl. sensor/actuator-technologies, and this (the SYSTEM) is, where the complexity resides.
Third place: engine control functions (NOT software!). This is to describe, what is needed to fully control the engine. The "What need to be done".
As such this provides the requirements of ECU hardware and ECU software.
ECU hw & sw do the implementation and optimization; the "How".
That's why I strongly believe, that this forum needs extension "Engine Technology" and "System Analysis".
This thread would belong to "System Analysis" together with ion-Sensing.

Having said that, let's return to in-cylinder pressure sensing.
Did anyone really apply those diesel glow-plug sensors for a gasoline engine?

kr, sepp2gl

[sepp2gl]

@nmstec:
"for locating TDC"?
Why would you want to apply such an invasive technology just for locating TDC?

[MHTSOS]

For when you have no access to the crankshaft, ie a Harley engine.

Στάλθηκε από το VOG-L29 μου χρησιμοποιώντας Tapatalk

[sepp2gl]

That's why, I think this forum (and most others) needs an engine analysis chapter and a system design chapter.
The conditions of a specific engine need to be clarified in a separate activity and not in a software or (ECU)hardware chapter, and within it should be documented in a kind of engine-datasheet.

@mhtsos: Would you please cure my curiosity, why there is no access to the crankshaft of a Harley-engine?
Please excuse my stupid question.
kr, sepp2gl

[mk e]

Would you please cure my curiosity, why there is no access to the crankshaft of a Harley-engine?
Please excuse my stupid question.
kr, sepp2gl

Its not that there is not access, its that there is no access without pulling the side cover and fitting a degree wheel which is the standard approach but was deemed to much bother iirc. The older ones had a plug in the case to check timing left over from the points days but on the new designs that's gone, so pull the side cover is the only way to physically check it these days from what I understand.

[mck1117]

why there is no access to the crankshaft of a Harley-engine?

There are zero exposed spinning parts on a Harley engine until the drive sprocket on the belt. You can't see any part of the crankshaft, camshaft, timing gears/chain, etc. All of those are behind covers and bathed in oil, so if you tried to run the engine with one of those covers off, all your oil would pour out.

[sepp2gl]

Its not that there is not access, its that there is no access without pulling the side cover and fitting a degree wheel which is the standard approach but was deemed to much bother iirc. The older ones had a plug in the case to check timing left over from the points days but on the new designs that's gone, so pull the side cover is the only way to physically check it these days from what I understand.

I understand and agree, that providing a timing-wheel to a crankshaft is a difficult issue.
But isn't it even more problematic to drill another hole into the combustion chamber for a Glow-Plug Pressure Sensor?
(Unless you need it only for the purpose of maintainance with a cold-motored engine.
Here you could use the spark-plug hole to get access for the GPPS.)

[mck1117]

But isn't it even more problematic to drill another hole into the combustion chamber for a Glow-Plug Pressure Sensor?
(Unless you need it only for the purpose of maintainance with a cold-motored engine.
Here you could use the spark-plug hole to get access for the GPPS.)

He didn't drill another hole, just put a sensor in the spark plug hole to test at cranking speed.

[mk e]

He didn't drill another hole, just put a sensor in the spark plug hole to test at cranking speed.

which I'm pretty sure gave him a number that is a few degrees before actual TDC...but as long as he's setting adjusting timing on the dyno it will all work out.

[sepp2gl]

Hmmm...
I still don't understand the rational behind this doing.
Has a Harley engine got two spark-plugs, so he can replace one?
If he is doing cranking- (motored-)Test without combustion only, what is it good for to know TDC in motored operation?

[mk e]

Hmmm...
I still don't understand the rational behind this doing.
Has a Harley engine got two spark-plugs, so he can replace one?
If he is doing cranking- (motored-)Test without combustion only, what is it good for to know TDC in motored operation?

No, no, it was a setup thing not a while running thing. He pulled out the plug and cranked while logging then used the traces of crank position (guess) and peak pressure to get a better guess at the real crank timing and changed the number in the setup to be closer to real.

[sepp2gl]

OK...got it now.
Thanks for clarification.

[nmstec]

OK...got it now.
Thanks for clarification.

https://rusefi.com/forum/viewtopic.php?f=4&t=2229&p=43433#p43433


Crankshaft is located nice and deep in the belows of the engine. So when trying to get inthe ballpark of tdc offset, we had a ripped apart motor that was just enough to see and calculate.
But also yes, harley has dual fire plugs.


mk e. you keep saying im off, dyno says i'm not. You said curve would be flat up top, as you saw, its not.

[mk e]

mk e. you keep saying im off, dyno says i'm not. You said curve would be flat up top, as you saw, its not.

I would have to dig up the original words, but I recall it looked exactly as expected, all lopsided due to leakage. The pressure curve would never be flat, it will start to drop as soon as leakage rate exceeds pressure gain rate. So a pressure rise and peak is expected ...2-5 degrees or so before true top, depending on how well sealed the rings are. I think what I probably tried to explain is that there is virtually no piston movement in the center 5 degrees and almost none in the center 10 so even a dial indicator is a very inaccurate way to find TDC in that area and standard practice is to stop .100" or so down in one direction and reverse to .100 the other direction and set center in the middle.

I have no idea how the dyno is telling you its correct? You could tell the ECU TDC is almost anywhere and still tune it just fine on the dyno so I'm not sure how that tells you anything? But this also means it doesn't really matter unless you're trying to share tuning tables with somebody who set TDC differently, but it you use you're setup and you tables you have no problem at all.

[nmstec]

OK...got it now.
Thanks for clarification.

https://rusefi.com/forum/viewtopic.php?f=4&t=2229&p=43433#p43433


Crankshaft is located nice and deep in the belows of the engine. So when trying to get inthe ballpark of tdc offset, we had a ripped apart motor that was just enough to see and calculate.
But also yes, harley has dual fire plugs.


mk e. you keep saying im off, dyno & oem ecu says i'm not. You said curve would be flat up top, as you saw, its not.

[mk e]

mk e. you keep saying im off, dyno says i'm not.

mk e. you keep saying im off, dyno & oem ecu says i'm not.

If you already had the number from the OEM ECU why did you not just use it and save all the time and bother of trying to measure it?

I'm sure a pressure sensor in the plug during cranking is WAY better than guessing ......

[nmstec]

mk e. you keep saying im off, dyno says i'm not.

mk e. you keep saying im off, dyno & oem ecu says i'm not.

If you already had the number from the OEM ECU why did you not just use it and save all the time and bother of trying to measure it?

I'm sure a pressure sensor in the plug during cranking is WAY better than guessing ......

Again, because I don't. OEM ecu (well tmax in this case) does not show tdc offset. It does however show what timing it runs. Considering we did a few baseline runs, we know how much whp to expect out of it. So translation. Cylinder pressure tool did its job properly, I am dead on with timing, you said won't work, it worked. Thank you. Have a lovely day.
OR we could just get back on topic of cylinder pressure sensor. Reason why I did it has near nothing to do with why we want it.

[mk e]

Again, because I don't. OEM ecu (well tmax in this case) does not show tdc offset. It does however show what timing it runs. Considering we did a few baseline runs, we know how much whp to expect out of it. So translation. Cylinder pressure tool did its job properly, I am dead on with timing, you said won't work, it worked. Thank you. Have a lovely day.
OR we could just get back on topic of cylinder pressure sensor. Reason why I did it has near nothing to do with why we want it.

Reporting you got the same (similar?) hp for 1 tune as another tune, then implying that means the crank position setting is dead on is a non sequitur.

Mischaracterizing my comments about a method being inherently inaccurate to mean "won't work" is dishonest.

Just sayin.....

[mck1117]

Locked for a few days since you people can't keep it together.