PorKen

I heated the plugs with a torch before trying to remove them. Not sure if it helped, but they came out easily after the initial *crack*.

RCinXS

Thank you very very much Ken, for the input on removal.

I'll do the same on the original 16V plugs if I ever get the 32V plugs.

By the way Ken, the rest of the project is coming along nicely and thank you once again for all of your advice on the other issues that have been overcome!

RCinXS

Having given up on the vendors to pull the mounts from a junk block and failing to find anyone else willing to go through the hassle, I decided just to pull the existing non-knock sensor plugs and drill and tap them.

In case anyone else ever wants to do this.

Steps:

1 remove plugs with a 8mm hex key (front plug) and 17mm socket (rear plug).
2 screw plug(s) into 14mm nut (to hold on vise).
3 Drill them out with 17/64" drill bit.
4 Tap holes with 8mm, 1.25 tap.
5 Use a bolt or cap screw to reinstall the plugs using Locktite. I used blue.
6 After Lock tite sets up, remove bolt.
7 Install Knock sensor.

I'm using 944 Knock Sensors simply due to the custom harness that I need to make anyway.

The plugs for the 944 sensors are the same as the Fuel Injector plugs, so it makes it a bit easier than dealing with finding Bosch plugs.

Pix

Job Done

They end up with one dead center of cylinders 1,2,5 and 6 and the other dead center of 3,4,7 and 8.

You simply couldn't ask for better knock sensor locations.


The new EMS will compare knock versus plug firing to determine which cylinder has knocked.

I think the LH and later 32Vs do this also.

Cool thing is the ability to adjust the amount(s) of retard due to knock severity.

And can be setup to adjust in stages just like the 32Vs do.

PorKen

Smart. (WDITOT?)


I like the factory sensors because the valley will inevitably fill with coolant, fuel, oil at some point.

RCinXS

Absolutely on the oil thing. The factory sensors kick up to keep them out of any oil or coolant.

Of course, part of my Spring project is a complete reseal.

Euro Heads are back. Turns out that the exhaust ports had been ported and polished too. Just couldn't see it for the drastic amount of carbon.

2-3 weeks and the engine should be back in conplete with true sequential FI.

Then the real fun begins. Tuning through the Laptop.

Lizard928

I was thinking just drill them part way through, and tap.
Or maybe weld up the bottom of the hole afterwards to prevent junk from being able to fall down inside the engine.

RCinXS

Front plug is only about 5/8 inch long. Not really enough to tap if you don't go all the way through. Safest way was to remove the plug. Broke loose easy enough. No thread locker from the factory.

The rear plug, which is usually used for a rubber mount for the air guiide, has more depth to it. It is already threaded for 6m. You could drill and tap this one out without removing it from the block as the 6m threads go down about an inch already. Just mark the bit with a piece of tape and stop drilling when the tape hits the plug and then tap with the 8m. This might give you 1/2 - 5/8 inch of good threads for the bolt. That should be quite adequate for the sensor 8m bolt. You could also taper the bolt at the end if you wanted to catch the partial threads at the bottom from the pointy end of the tap.