I asked Bill Simkinson maker about 50% of the probes used in USA made CHTs/EGTs instruments. So he suggests the gasket type probe should be in contact with head and then the extra washer the spark plug. I await new copper spark plug washers from Aircraft spruce as I like the big surface area compared to the local copper washers
Ian McPhee ---------- Forwarded message ---------- From: PATRICIA SIMPKINSON <[email protected]> Date: 20 March 2012 04:55 Subject: Re: Question To: Ian Mc Phee <[email protected]> Good to hear from you Ian. With any gasket type probe it wants to be under any other washers so it gets max amount of heat transfer especially as some spark plug washers are rolled steel which is a poorer heat conductor than copper. All the best, Bill ------------------------------ *From:* Ian Mc Phee <[email protected]> *To:* Bill Simkinson <[email protected]> *Sent:* Sat, March 17, 2012 8:47:31 PM *Subject:* Question Hello Pat and Bill I trust you are still both going strong Often in VW engines we use 2 spark plug washers as theis prevents plug sticking too far into head. Now if you have a sensor I have heard it should be between plug and second washer which is best to be a wide copper washer. What are your thoughts Ian McPhee
