2000 Block vs 2001 Block - Knock Sensor
#1
2000 Block vs 2001 Block - Knock Sensor
I am pulling my 1999 block with large
threaded knock sensor and going to install a 2001 block with
smaller threaded sensor.
Knock sensor
19xx to 2000 Blocks
Uses a 1 wire with a large thread in bolt around 1/2" to 5/8"
2001 forward Blocks
uses a 2 wire with a smaller threaded bolt 1/4"
I have read...
1. Can Drill & Tap smaller hole to fit 1 wire larger sensor.
2. Can Use Blue wire and ground Gray one on the sensor.
3. Use a reducer - large female size to male 1/4 and
thread into 2001 block 1/4" small hole.
Pics I have found attached with my notes.
Thanks for any input on this, I know I am not going to let
a damn 1/4 hole size change stop me from getting that 2001
block in my 1999 Blazer.
Bill
threaded knock sensor and going to install a 2001 block with
smaller threaded sensor.
Knock sensor
19xx to 2000 Blocks
Uses a 1 wire with a large thread in bolt around 1/2" to 5/8"
2001 forward Blocks
uses a 2 wire with a smaller threaded bolt 1/4"
I have read...
1. Can Drill & Tap smaller hole to fit 1 wire larger sensor.
2. Can Use Blue wire and ground Gray one on the sensor.
3. Use a reducer - large female size to male 1/4 and
thread into 2001 block 1/4" small hole.
Pics I have found attached with my notes.
Thanks for any input on this, I know I am not going to let
a damn 1/4 hole size change stop me from getting that 2001
block in my 1999 Blazer.
Bill
Last edited by cdtek101; 02-01-2017 at 11:09 AM.
#3
I'd go with option 1. Drill and tap the hole and keep everything 1999. Option 2 is easier if you're sure it will work. Option 3 I wouldn't do because I'm too fussy. The piezoelectric crystal in the knock sensor produces electricity when shaken. Raising it's mounting point even that little bit may create a pendulum effect where it's moving farther than it would in the stock location. I don't know if they are that sensitive, but I know my luck when I try to take the easiest way.
#4
I'd go with option 1. Drill and tap the hole and keep everything 1999. Option 2 is easier if you're sure it will work. Option 3 I wouldn't do because I'm too fussy. The piezoelectric crystal in the knock sensor produces electricity when shaken. Raising it's mounting point even that little bit may create a pendulum effect where it's moving farther than it would in the stock location. I don't know if they are that sensitive, but I know my luck when I try to take the easiest way.
If option 2 didn't work it would be a mission impossible to
drill tap after motor was back in.
#5
FYI
1 wire sensor is 1/4" NPT thread
2 wire sensor is supposed to be 5/16-18 thread
Option 2 will not work - don't do it - check the wiring schematic.
Drill and tap the hole in the 2001 block to 1/4 NPT if you can, and screw in the 1 wire sensor. It doesn't have to seal - just be solid.
I have also recently heard of screwing the 1-wire sensor into the 1/4 NPT coolant hole in the side of the head and extending the wiring to that location.
1 wire sensor is 1/4" NPT thread
2 wire sensor is supposed to be 5/16-18 thread
Option 2 will not work - don't do it - check the wiring schematic.
Drill and tap the hole in the 2001 block to 1/4 NPT if you can, and screw in the 1 wire sensor. It doesn't have to seal - just be solid.
I have also recently heard of screwing the 1-wire sensor into the 1/4 NPT coolant hole in the side of the head and extending the wiring to that location.
Last edited by LesMyer; 02-03-2017 at 03:38 PM.
#6
FYI
1 wire sensor is 1/4" NPT thread
2 wire sensor is supposed to be 5/16-18 thread
Drill and tap the hole in the 2001 block to 1/4 NPT if you can, and screw in the 1 wire sensor.
I have also recently heard of screwing the 1-wire sensor into the 1/4 NPT coolant hole in the side of the head and extending the wiring to that location.
1 wire sensor is 1/4" NPT thread
2 wire sensor is supposed to be 5/16-18 thread
Drill and tap the hole in the 2001 block to 1/4 NPT if you can, and screw in the 1 wire sensor.
I have also recently heard of screwing the 1-wire sensor into the 1/4 NPT coolant hole in the side of the head and extending the wiring to that location.
Did you mean drill tap 2001 block which is 1/4 already
to 5/16-18 thread for larger knock sensor size bolt ???
And -
?? - The 1 wire sensor 5/16 size.. would not fit in coolant
hole if coolant hole is only 1/4 ?
From pictures I have seen the (1999) 1 wire sensor looks like
a big boy around 7/8 or 1/2, hope to find out tomorrow
when my guy pulls it out of 99 block.
Last edited by cdtek101; 02-03-2017 at 04:28 PM.
#7
Confused Les - Did you get sizes backwards ?
Did you mean drill tap 2001 block which is 1/4 already
to 5/16-18 thread for larger knock sensor size bolt ???
And -
?? - The 1 wire sensor 5/16 size.. would not fit in coolant
hole if coolant hole is only 1/4 ?
From pictures I have seen the (1999) 1 wire sensor looks like
a big boy around 7/8 or 1/2, hope to find out tomorrow
when my guy pulls it out of 99 block.
Did you mean drill tap 2001 block which is 1/4 already
to 5/16-18 thread for larger knock sensor size bolt ???
And -
?? - The 1 wire sensor 5/16 size.. would not fit in coolant
hole if coolant hole is only 1/4 ?
From pictures I have seen the (1999) 1 wire sensor looks like
a big boy around 7/8 or 1/2, hope to find out tomorrow
when my guy pulls it out of 99 block.
1/4" NPT (national pipe - taper) is considerably larger than a 1/4-20 or other similar straight thread since it is formed into the outside of a 1/4" pipe having a nominal outside diameter of 0.405".
#9
I was just going off standard bolt sizes,
was wondering what NPT stood for.
Last edited by cdtek101; 02-03-2017 at 06:21 PM.
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