Spark Plug and Thermocouple Recomendations

[britishrocket]

Hello all,

I'm in the process of building a DIY gas turbine engine using a generic Chinese made T3/T4 turbocharger.

I appreciate that these questions have been asked many times before, but here goes:-

What is a typical spark plug that is used in these engines?

Can anyone give me a steer to a reliable thermocouple with electronic readout unit that can be used to indicate turbine inlet and outlet temperatures?

Thanks in advance to you all.

[richardm]

Most often an automobile type spark plug will do. Much cheaper than the real "aviation " type. Im using an automotive EGT type thermocouple and gauge I found that they re not too expensive.But some have a faster response time than other. For your thermocouple look for a type K junction and if the cable is long enough for your application It can be extended but everything must be type K. the extension cable it sel and connector.
By using a different metal you will be making another "bimetallic" junction that will result in false readings.

[britishrocket]

Thank you for the response. I understand about the k type thermocouple.I do have some k types already. I was however looking for some info on the plug and play type you find on eBay, with the readout electronics included. I have heard they can be unreliable.That said I know people use them, so are there any recommendations on a reliable unit?

[racket]

I've recently purchased this thermometer www.ebay.com.au/itm/163642935904?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20230811123856%26meid%3D6f8d9f91327b4f329ac2f683924de91a%26pid%3D101770%26rk%3D1%26rkt%3D1%26itm%3D163642935904%26pmt%3D0%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2%26brand%3DUnbranded&_trksid=p4375194.c101770.m146925&_trkparms=parentrq%3A5e32544718e0ac6b8b8aebb4ffffc644%7Cpageci%3Aa18daa17-e711-11ee-b5ef-de8034dcefff%7Ciid%3A1%7Cvlpname%3Avlp_homepage

along with two more thermocouples www.ebay.com.au/itm/186263907933?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20230811123856%26meid%3Dfc8743801c4c4e9e8d56e3ac293fdfc3%26pid%3D101770%26rk%3D1%26rkt%3D1%26itm%3D186263907933%26pmt%3D1%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2%26brand%3DUnbranded&_trksid=p4375194.c101770.m146925&_trkparms=parentrq%3A5e354d5218e0ad98cdcc809affffc48a%7Cpageci%3A15aeaa98-e712-11ee-8e12-369e02c3a31d%7Ciid%3A1%7Cvlpname%3Avlp_homepage

so that I'll have 4 thermos in my jetpipe as I'm trying to workout if I've got a hot streak or a cold streak producing the variations in my temps .

These thermocouples have expose sensors for fast response times...............BUT please don't use them for TIT , only TOT as we don't want them failing and going through the turb wheel .

Sparkplugs, as Richard said , can be auto plugs with auto coil , gap can be increased as we have low air pressures , I only use an auto plug for my A/B , though I use a turbine ignitor in the engine thanks to Andy and his high energy spark system .

Cheers
John

[richardm]

I have something similar to this I also own a thermometer similar to the one John is referring to I ve use it to crosscheck the EGT gauge accuracy Not too bad but I change the thermocouple that came with it for a more sensitive one. Just as John described. For me I' d rather keep my thermometer ( expansive accurate instrument) and sacrifice a cheaper gauge if anything goes wrong.Also more convenient as the gauge is in a panel along with other gauge. I think the accuracy goes according to cost so not worth putting money on an inaccurate gauge embellished with gadgets like selectable display colors etc...


www.amazon.ca/Pyrometer-Exhaust-Temperature-Display-Vibration/dp/B09YVCCPVF

[britishrocket]

Thank you John for your time and the links.Much appreciated.

[britishrocket]

Thanks Richard for your time and the link.

[richardm]

No problem. Hope it helps That' the purpose of the forum Maybe you ll be helping others later from your experience.