Feeling sheepish, shoulda thought about the knock sensors...

I may have painted myself into a bit of a corner here, guys. Since everybody is social distancing, the gathering to point fingers and laugh will have to be done as a Zoom meeting. Not quite sure how I'm gonna salvage this, but y'all should get a few chuckles before this is solved. Without further ado, here is the chronicle of my stupidity-
Some 5 years ago, I started building a serious stroker motor designed from the ground floor to take a giant shot of nitrous. Spared no expense. All the goodies: Splayed 4 bolt mains, ARP studs, Stress-relieved block, oil squirter jets to cool the pistons, H beam rods, the whole bit. Including one more thing that has led to my current state of dismay. I decided to reinforce the bottom half of the block. My thinking was, with the reverse cooling that makes the LT1 so special, using block filler up to the freeze plugs should not have any significant effect on cooling. And with an intended 500+ horsepower nitrous system on my mind, the block reinforcement seemed prudent. The one detail I failed to consider until this fateful day was this- Knock sensors screw directly into the water jacket. At the very bottom of the block by the pan rail. My folly became evident as I happily crossed items off my ever-dwindling list of "final details" before lighting off this beast and scaring every neighbor within 16 blocks. I bought brand new knock sensors, name brand US-made ones, no less. "Nothing but the best for my baby", I was thinking to myself as I unscrewed the steel plug from the threads I painstakingly chased with a brand new tap when prepping the block so many moons ago... Then a bit of concern: Is that corrosion in my beautiful high dollar block? I swear I just saw some white powder fall out of the hole when the plug came free. I better grab a flashlight and have a closer look! When I return, I roll a little further under the frame rail for a better angle to see into the hole. And that is when horror overtook my idyllic Father's day morning project. For there, where the bottom of the plug had been 5 minutes previously, was a solid wall of white. The very best, concrete-hard, Stiffer-Than-Steel block filler, flawlessly poured many months ago, is precisely where water needs to be for the new sensor to do its thankless job.

When you all are done rolling on the floor, holding your sides and thanking the good Lord in Heaven that you have more sense than I do, I could surely use some help. Namely, WHATDOIDONOW? Will the sensor still detect knock if I drill and tap a new hole 3 inches higher up, next to the freeze plug? Is that too far from the crank, where the evil detonation rumbles are transmitted to the block? Is there a way to inject a small pocket of water just in front of the sensor, that will allow it to feel the vibration it is looking for? Can I make a reducer plug for the Temp Sensor hole, and put it in the driver's side head itself? Do I have to peel the whole top half of the engine off, so I can stick a masonry drill through one of the water holes in the deck and reconnect the sensor hole to the higher water level? I feel more than a little like I may vomit. I was literally days away from the culmination of a project that has sidelined my favorite toy for half a decade, and now it might sit the other half. HEEEELP MEEEEEE!!!

The knock sensor(s) don't need to be in contact with water to work.

They are listening for the vibrations in the block itself that occur with a knock event.

As long as they still screw in tightly, you are good to go.

- J

JaySS wrote:

The knock sensor(s) don't need to be in contact with water to work.

They are listening for the vibrations in the block itself that occur with a knock event.

As long as they still screw in tightly, you are good to go.

- J

That is very good news! I was under the impression that the water was what transfers the vibration to the sensor. If not then I can keep moving forward!