Vauxhall cylinder pressure sensor

Hello,

I am on my very last step to create a digital steam (yes, steam) engine indicator. The sketch is written, the rotary encoder works, the display displays. The only loose end is the pressure sensor for the cylinder to draw the pv-diagram.

I originally used those cheap 1/8NPT pressure transducers you can find on ebay for around 10 bucks, but their limitations soon showed me there was a reason why cylinder pressure sensors are more expensive. The cheapest solution I found is using Vauxhall glow plug pressure sensors (probably with the glow plugs as unused dead weigth, but who cares as long as I can get it to spit out some useful data)

The only loose link would be to get datasheets of those glow plug sensors (or sensor glow plugs) Unfortunately, I haven't been successful yet. Does anyone have an idea?

There are these pressure sensors, some rated up to 1600 psi, surely that should be sufficient.

https://www.ebay.com.au/itm/184866241613?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20201210111314%26meid%3D8069980750dd4db49da9a04dc489ae22%26pid%3D101195%26rk%3D9%26rkt%3D12%26sd%3D274426373321%26itm%3D184866241613%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseWithPLXWeb%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851&amdata=cksum%3A1848662416138069980750dd4db49da9a04dc489ae22%7Cenc%3AAQAGAAACAPzOhTKduD0sA8ZT3vYvaPP4EYb9cjdDRccHic7SCl3W5bJD7xOwKQdm6IK2SLqByrYpvM4TmaR85%252Fn00ljxFu94a4fo76K424OJTRm%252F3b%252BKTF3Cy%252FL2CGeBcRh0s0mfyHdUP4qwbZl8gnCtoBJjq4BitlXWj52YM9uVayceCYR7wGSRvZVQeNYRtdgDpZ0YJPF7IX1K1egmMtkxamkgLm%252Bb1rPEr1Juaq36jvoQnGDQlmHlL8lGJ3ZVRFDKGBQo45Ax8Qf6PrhIVRRh899QnV%252F%252BxzspIDW50CmISYwJTPkjNW0golPnAxk8Wh9VlXuQ2fjIuDuTHI76BW4rc4t1O9eYLibbJLoHslNTp4otsHNEDxtkyQgDEZfoY1dJTmZLcvZ0fijGbN1mJQFzm6MFvuo8XGHDsQjwhAU%252BHqlIJBOYbVf51%252BIg6Kqjhj27V78qJ8KiVB9xQiMipZa8ipzjJmz9GfMljU4fwCAl2Rube4w44YwXKS2Qk30yLMmGaD4d69PB3FkqsS5A3kIWw0mamsPHk4dJO2rJoGDtZXl8JnhOxdmXvH3WWynM5W0YXBpn48trRdyUBg1bK0NGa0Z5Hx7%252F3GE2BlgmYQA16y4XOwD2PVHZ2aSSSOO3e1fc2y4O231SbMRRzC35M6iRY%252BqaVV0VmPbbWmfcQI8pcIpR2lNp%7Campid%3APL_CLK%7Cclp%3A2047675

This discussion group has done some useful research on these kinds of sensors:
https://rusefi.com/forum/viewtopic.php?t=919&start=30

Hmmh, thank you. That looks like I belong there.

There us no such thing as a free lunch - you need to look at industrial sensors and their spec before looking at cheap stuff . You get what you pay for …

A 1600 psi transducer has far too big a range , I’m guessing you want 100psi , possibly even an absolute device if you think there may be partial vacuum .

Op never stated what range was required.

You can find fuel pressure sensors for Ford (International Harvester) 7.3L Powerstroke diesel engines on Amazon. They are surprisingly cheap (around $10 each) and rated at about 3,000 psi. They aren't super accurate but probably good enough for what you're doing.

Cedarlakeinstruments: No, unfortunately, they're not good enough. Their response time is not usable.
I'm already in an advanced stage and have found out that I really need high-end dynamical pressure sensors. I could use those cheap chinese pressure transducers in the past, but only by tuning the variables into useless regions (the sample per rotation had to be reduced to 20ppr, which completely sabotages the project's idea. And it only worked in very low rpms - even for steam engines, it wasn't usefull)

I indeed haven't stated the pressure range, but it has to be able to measure 100 Bar ideally, which translates into 1450 psi. It's not going to be a slow steam locomotive type of engine mind you. So, directing the gaze at ic engine cylinder pressure sensors is a pretty logical step.

hammy: Well, these standard proverbs don't fit here. I am well aware of the cost of high quality sensors and it's my luck that those spark plug pressure sensors are high quality and at least somewhat affordable due to being mass produced.

It's the most economical way to get a hold onto any halfways useful, highly dynamical pressure sensors, which can also tolerate heat. Only the environment they're going to be used in already excludes basically all sensors a private person can buy as far as my research goes. I've already rung up over half the globe for that.It's a very specific niche application, leave alone for steam engines.

But i've found a solution I think. A producer is interested in the project for the moment. Let's see.