Knock sensor mounting

[Jim Stabe]

The stock mounting location for the knock sensor on the LT1 is just above the pan rail screwed into a 1/4" npt hole into the water jacket. The block hugger headers come down right next to there and I'm afraid that the heat will burn the wire/sensor. Would the sensor still work if I screwed an iron street elbow into the block and mounted the sensor to that? It would still have a solid connection to the block through the pipe fitting.

[BlownMGB-V8]

Jim, I think it would be OK but what you are doing is basically picking up vibrations with a microphone so any solid physical connection should work. Using aluminum could conceivably work better but I doubt you'd be able to tell the difference. I used a steel thread adapter on one of mine but as I used two of them and did no specific testing I can't say with any certainty that it didn't affect the signal. Not much help of course.

But I did some study of them and the main thing seems to be getting in the correct frequency range. The biggest variable is the metal the heads are made from, as iron and aluminum have different resonant frequencies. Then you go to things like the vibrating mass and that is somewhat affected by what it is attached to. All of which means it matters more to have the right sensor than the method of attachment. Sort of like using a mechanic's stethoscope I guess.

Jim

[Jim Stabe]

Good to know. Mine don't mount to the heads so that is why I thought about using an iron street L to match the block material. Mine only came with one but some of the later LT1's had one on each side so I think that is what I will do. They just wired them in series.

[Jim Stabe]

Problem solved - I found a boss with a blind 3/8 threaded hole on the other side of the block that was only 2" away from the drain hole that mirrored the original location of the sensor. Fortunately it was 2" in the right direction - away from the headers. Drilled it out and tapped it with a 1/4" npt tap and the sensor screwed in perfectly. The original hole on the other side of the block put the sensor behind the headers and physically interferred with the sensor.
 

[roverman]

Jim, Looks real clean. Going to eng./chassis dyno ?  Cheers, roverman.

[Jim Stabe]

It will have to go on a chassis dyno to get it ECU tuned. Getting closer.