Alternative location for Cylinder Head Temp Sender, Considering one of the #3 Cylinder exhaust studs Options

[bobhasissues]

I have some new 914 2.0 repro heads from DRD. The new heads use a 12mm spark plug rather than the stock 14mm. I want to use a ring terminal type Cylinder Head Temperature Sender under the #3 spark plug just as I did on my stock heads. The problem is the outside diameter of the ring terminal of my 12mm CHT sender is larger than the bore of the spark plug hole so I can't put the sender under the #3 plug as designed. As many of you probably do, I had the 14mm ring terminal sender on my stock heads and that took a lot of manipulating of the terminal stem to get it to fit. This is way worse, the OD of the 12mm ring will not even fit into the plug bore.

I asked Darren at DRD what to do and he suggested to use the fuel injection CHT location out on a fin by the intake manifold. I don't like that idea because it seems too far away from the chambers to pick up any major temp fluctuations.

I'm considering changing to an 8mm ring terminal on the sender and double nutting it onto one of the #3 exhaust studs.

Anyone have a better location?

[wndsrfr]

I had the same issue with the 12mm plug and got some excellent support from "The sensor connection" guys. They worked with me sending back & forth several CHT's and finally got it right with a 12mm ring that will actually fit down in the recess on the head. Mind you, it's still a tight fit & you have to carefully bend up the tab, but their 12mm ring is a true 12mm, not 13mm as some vendors are supplying. No vested interest, just have had great service from these folks:
http://www.thesensorconnection.com/index.shtml

[913B]

I had the same issue with the 12mm plug and got some excellent support from "The sensor connection" guys. They worked with me sending back & forth several CHT's and finally got it right with a 12mm ring that will actually fit down in the recess on the head. Mind you, it's still a tight fit & you have to carefully bend up the tab, but their 12mm ring is a true 12mm, not 13mm as some vendors are supplying. No vested interest, just have had great service from these folks:
http://www.thesensorconnection.com/index.shtml

Sorry but I am reviving this old thread. I want to install the CHT under the spark plug like all the cools kids have. So is this the one to get or have there been better solutions? I am preparing myself for the idea of dropping the engine to perform the modification on the head. That's not the only reason to drop the engine. I need to install the crank sensor for my Microsquirt conversion too.

Thanks All!

[worn]

I had the same issue with the 12mm plug and got some excellent support from "The sensor connection" guys. They worked with me sending back & forth several CHT's and finally got it right with a 12mm ring that will actually fit down in the recess on the head. Mind you, it's still a tight fit & you have to carefully bend up the tab, but their 12mm ring is a true 12mm, not 13mm as some vendors are supplying. No vested interest, just have had great service from these folks:
http://www.thesensorconnection.com/index.shtml

Sorry but I am reviving this old thread. I want to install the CHT under the spark plug like all the cools kids have. So is this the one to get or have there been better solutions? I am preparing myself for the idea of dropping the engine to perform the modification on the head. That's not the only reason to drop the engine. I need to install the crank sensor for my Microsquirt conversion too.

Thanks All!

The issue is that it can be difficult to properly thread a spark plug into the head, and it is even harder with a copper ring around the plug threads. Tradition has used such an instrument to measure head temps, so using number three spark plug has become a kind of standard. Is it etched in stone? Heck no! The factory made a special drilling for its own cylinder head sensor, but it is something that can be related to the experiences of others. Hmmm, my cylinder heads melted away at xyz degrees. George can correct me, but my recollection is that when I called AA he said that a CHT gauge would “just scare me”. And it has on many occasions, but the motor still runs…
Moral of the story is that the instrument will allow you to start making measurements. These can come in useful. It certainly tells when you stress the motor, and when you let it rest. It is summer while we have it. Good luck!