Hello All,
I've got to put in a LS1 knock sensor in the LS2 block knock sensor location. I already know that the hole needs to be tapped to M10x1.5 hole size, but when the motor was assembled, it was forgotten to tap the hole to the proper size. There are other knock sensor locations right above where those holes are, and that is where I currently have my knock sensor (LS1 application). Problem is they are too close to the headers, and one of them had a melt down. I can't remove the old knock sensors because the headers are too close to them, and I can't tap the holes because there isn't enough room. The only option I have right now is to resize the thread of the LS1 knock sensors. What size is the LS2 knock sensor thread?

Thanks,
Adrian

 

M8x1.25x40, 22 Thd, 18 Od, 8.8

 

Thanks for the thread size! But there is no way I'm going to be able to re-thread those knock sensors. The pitch is different, which would just mess up the thread. Thanks anyway....guess I'll have to figure out a way to get in there and tap that hole...

Thanks!
Adrian

 

I lied, I just ground down the original threads, and then put the die to it, first time ever, and man is it a pain in the ***!! I hope it works.....

 

I am glad my engine was out when I did that.

 

LOL, no kidding, mission accomplished, went right into the stock LS2 sensor location, the re-threading of the LS1 sensor worked! Now I just hope that it registers in the PCM and the sensor actually works. Otherwise i'll be rather dissappointed haha.

Alright, off for some tuning!

 

Did it work? I'm going to have to do the same thing
TIA

 

can u post pics of where the sensor needs to be. I have a LS2 block on the stand and I put my LS1 knock sensors behind the motor mounts. They threaded right in, im wondering if I need to move them

 

"Same both sides" means walk around to the other side of the engine and do the same thing there.

 

The alternative doesn't work with 1 7/8" headers, I found out the hard way.

 

do the sensors work?

 

yes they are installed and working.

 

am i looking at this right? your alternative arrow points to a engine mount hole?

 

Yes, some mount brackets only use 3 of the 4 holes.
It's not a good solution, but may help somebody that forgot to tap out the LS2 knock bosses.

 

TTT
im getting ready to do a gen 3 to gen 4 block swap. i do not have motor mounts because i have motor plates in my car. does any one know the thread size for the 4 motor mount bolt holes? and even tho the sensors are susposta go in the "normal" hole in the picture does it really make a differance if they get installed in the motor mount holes?

 

It's written in green in the bottom right of my picture.
M10x1.5

 

Ahh duh. So any one think using the motor mount holes would be any different then the knock sensor holes?

 

when you say working does it show anything when you use the scanner that reports it actually showing knock thats real???

 

Does anyone know the size of these threaded holes? I am trying to put the knock sensor for an ls2 on the side of the block but need to find a mounting stud to make it work... thanks! Michael

This is what i am trying to do...