CHT question

[OneBulletDan]

Bought a three inch Westach CHT to sorta match my three inch tach. In the instructions, they mention that you might or might not want to remove the metal gasket on the spark plug before installing the thermocouple.
The therm connector measures .045", while the plug gasket measures .083".

My question is, would it be better to have the plug .038 closer to the piston, or .038 farther away by leaving the gasket on the plug?

While I`m begging for advice, is it OK to tape the metal lead to the wiring harness after you get a foot or so away from the plug, or does it get too hot to be next to wires? Do you guys drill an extra hole in the shroud to run the wires through, or do you just run `em out the spark plug opening?

`Tis better to ask questions and appear to be an idiot than to remain silent and remove all doubts by screwing up a perfectly good piece of machinery.

[OneBulletDan]

Twenty eight lookers and no answers? *?

5If5Ke5Fc3N23l53Hdc3v12fc8c683c101556.jpg (24.5 KiB) Viewed 2704 times

[Fishman43]

I'm lookin because I want to know the answer as well

[evilone]

My question is, would it be better to have the plug .038 closer to the piston, or .038 farther away by leaving the gasket on the plug?I would remove the gasket

is it OK to tape the metal lead to the wiring harness after you get a foot or so away from the plug? Yes

Do you guys drill an extra hole in the shroud to run the wires through, or do you just run `em out the spark plug opening?I run mine out spark plug hole

[evilone]

By the way...i'd remove the gasket just because i'd rather have the spark further in the mix than further out.

[mousewheels]

The thermocouple wires conducting heat to nearby wiring is not an issue, temperature drops pretty fast in the bitty wires. Also, there's all that cooling air under the shroud.

I like to route sensitive wiring away from the ignition as much as possible. The thermocouple is less than 0.040v and even into the 0.010 range depending upon temperature and thermocouple wire type (Type J is higher output, Type K is used too, and is under 10mv below 470F.). Thus keeping away from the coil wire is a good start. No need to make it a tach pickup too

My CHT wire goes away from the plug ASAP - then down/out the opening cooling air exhausts over the intake/carb area.

[OneBulletDan]

Thanks, guys. Will do!