EGT probe and installation...

[dnb]

It's about time I made use of the EGT monitoring facilities in the new ECU...

I have a spare lambda boss (std M18 thread, not the silly standard Griff ones!!) that is currently blocked up with an old sensor. I need a blank plug to drill out and tap with a 1/4 BSP thread for a K type thermocouple to save me having to weld new fixings in the exhaust. Where can such plugs be obtained at short notice?

The next thing is what is a sensible maximum safe temperature for exhaust gasses on the Griff?

[mongoose]

Hi David,you could try Graham Goode Racing for the wideband lambda blanking plug.I've dealt with them and service was good and quick.There is also a company on ebay(salometrading) that sell the 'Innovate' wideband lambda kits and accesories,and also sell boss's and plugs seperately,jusk key in 'wideband lambda' in the search.
No idea about EGT sorry(one for Green V8S i feel),but i'd love to know more about why it's so usefull?

Edited by mongoose on Monday 17th July 17:16

[dnb]

Thanks. Going with the ebay one I think - I don't need anything fancy as it's only a temporary thing. (I don't want to drill more holes in those shiny manifolds!!)

I'm starting to push the ignition timing as far as I dare ready for the Growl RR. (I don't want to come last) and I am beginning to lean the fuelling out on cruise (I want to get there on less than a tank of petrol). The EGT getting too hot (along with the knock sensor) is a good indication that I'm going too far.

Is Mr GreenV8S around?

[GreenV8S]

If you only want a comparision before/after or looking at diffrences between cylinders, you can just jubilee clip a thermocouple to the outside of the exhaust at the point you're trying to measure (ideally, up by the head). K type thermocouples are common and cheap. For a slightly more permanent fixture that's still cheap you can simply weld a short tube onto the side of the header and insert the thermocouple when you want to take a reading. A thermocouple actually in the gas stream will be more accurate and respond quicker. My ZT-1 came with a handy screw-in thermocouple and has a dash display/logging capability which is potentially handy, I guess you will have something similar in mind.

It sounds as if you already have a threaded thermocouple and plan to use a wideband plug as an adapter? Sounds easy enough. Any of the places that sell wideband monitors will sell plugs and bungs, I bought a few of each from GGR in Leicester so I could transfer the kit between vehicles, they only cost a couple of quid and you can choose steel/alluminium alloy. Steel more durable obviously but alloy easier to work if you're after a quick hack. I'm sure they do mail order. Or, given you know the thread, you might well find that Think Auto have an adaptor on the shelf, they'd be able to supply plugs etc too of course.

[dnb]

GreenV8S said:

It sounds as if you already have a threaded thermocouple and plan to use a wideband plug as an adapter? Sounds easy enough.

Exactly right. I had a root through the cupboards last night and found a Subaru engine oilway bung is absolutely ideal for this job. It looks like I don't need to part with cash after all

Now, does anyone have an idea about the temperatures I should (and shouldn't!!) be seeing?

Thanks.

[GreenV8S]

God only knows. It'll probably start at a couple of hundred off load, 500-600C on load, 1000C is too hot. Something like that. I assume you're going to see where it is and then monitor EGT for a sudden rise as you lean it off?