Bosch knock sensor

[CT9A]

Can I drill the bosch knock sensor to 10mm without damaging it? Anyone tried that?

[stevieturbo]

Helicoil where it bolts to down to 8mm or something, or make up a 10-8mm stud.

I considered drilling it....but it's probably not a great idea

[jezzpalmer]

Hi,

I'm presuming you are replacing (or have replaced) your stock 4G sensors with Bosch units?
I was about to post a thread about the asking about the virtues of the stock 4G sensor, Vs the Bosch 0261231148; and I found this thread.

I have both but the stock sensor has no ground, just signal, and the Bosch have gnd and signal which seems a better idea. Is the bosch proven to be better than the stock sensor?

If you did use the bosch sensor, how did you go about mounting it in the end? I've found M10 x 1.5m to M8 x 1.25 reducing studs, but the block is tapped M10 x 1.25.
From what i can work out, an M8 helicoil should just about work in a hole already tapped 10 x 1.25, have either of you tried this?

Cheers,
Jezz.

[stevieturbo]

M10x1.25 is pretty common on Jap stuff, so wouldnt be hard to tap down a stuff to M8.

or as you say, helicoil it. Even if thread purchase wasnt great, wouldnt be the end of the world a knock sensor wouldnt carry any load.


Or bolt in the M10x1.25, cut flush and drill/tap to M8 or whatever size you need.

But 2 wires makes more sense to me. Reality might not really matter, especially as some OEM's offer 1 wire sensors, and you'd think they've done plenty of testing.

[jezzpalmer]

Thanks Steve.
I've ordered some M8 helicoils, as you say the purchase hasn't got to be 100%; I've got a spare block so I'll give it a go and see what happens.
I don't think screwing a stud in, flushing it and drilling/tapping will work, not with M8 anyway as there not enough metal.

If the helicoil idea fails I'll get a bit of M10x1.25 stud turned down and an M8 thread cut.

[stevieturbo]

If M8 is too big, just go M6. It would be plenty to hold down a knock sensor.

[jezzpalmer]

I can confirm that an M8 helicoil works nicely in M10 x 1.25, I havne't tried it on the block, but on a M10 1.25 nut. I screwed the helicoil into the nut, then screwed an M8 bolt into the helicoil.

The STI tap for the M8 helicoil seems to be about 9.8mm x 1.25, so inserting a M8 helicoil into a 10 x 1.25 thread is no issue.

[C. Ludwig]

I've also done a few this way. Works great.

[jezzpalmer]

I popped to the workshop and did it on my spare block last night, it did indeed work great.

[stevieturbo]

I can confirm that an M8 helicoil works nicely in M10 x 1.25, I havne't tried it on the block, but on a M10 1.25 nut. I screwed the helicoil into the nut, then screwed an M8 bolt into the helicoil.

The STI tap for the M8 helicoil seems to be about 9.8mm x 1.25, so inserting a M8 helicoil into a 10 x 1.25 thread is no issue.

I ran tap and helicoil into what was an M10x1.5 hole in my block. It worked fine too. Maybe a little loose, but perfectly strong for a knock sensor.