165 knock sensor sensitivity

[RDwoo10 at aol.com]

That is a good question.  I would imagine that as with anything that would be 
screwed into a pipe threaded hole that it is going to cut through the 
insulation enough that it will carry some current.  I think that this is a 
voltage device so that the current carrying capability is not really an 
issue.  I don't know enough about how it works other than it is a mic of some 
sort w/some value of sensitivity.  I went onto the gn-ttype site today & saw 
the one that they have & the output of the sensor goes into the input of a 
555 timer so I am not really sure how it works.  If anyone is really 
interested I will check it out & let you know.  

I called him today & he said that they do any one of three things.  the first 
step is to wrap some T tape onto the threads of the sensor & them make a 
diacom run.  if it appears to be knocking (where he thinks it ought not, & 
this is where it gets me)  remove it again & put a brass 90 between the block 
& the sensor.  this along w/the T tape.  he will make another diacom run & 
see what it is doing.  it it still knocks he will do the liquid rubber thing. 
 this, he says does the trick (if not he assumes that it is actually knocking 
& has a chip burned, provided the rest of the basics are good).  as i 
understand it, this are his tricks.  if all of this does not cut it then he 
assumes that the motor is knocking.

taking a step back i asked him why he would want to do that in the first 
place.  he said that when you add certain item to the car they are picked up 
by the knock sensor as knocking & retard the timing.  for example, if you add 
roller rockers to a motor that did not have them this can do it.  he also 
said that a solid roller cam (especially when revved to the sky) will do it, 
& make the motor think knock.  He also added a set of full length headers to 
a Camaro & that did it as well.  He had a baseline for them though.  He does 
a baseline for most of the cars that he does major work on.  

The question that I had to ask is how do you know.  His answer was that he 
takes the 15 minutes to run a baseline diacom run on any car that he thinks 
he might have a problem with before tearing it apart this way he has a 
reference.  

after reading this again, i am really sorry for the long windedness

Bob Wooten  
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