Knock Sensor Tech "Topic of Week! 2/12/2012"

[JeepsAndGuns]

I went through this when I did my 7427 swap. It also showed 2 diffrent knock sensors. One had a white connector, the other one was black.
The one with a white connector was what it said was for a manual trans, it also was the exact same part number as the one that came up for the 89 7747. I already had it installed for use with my 7747.
The black one was what it showed for auto. So like mentioned above, but be a ECM-PCM thing. With the manuals using the older style knock sensor.
I believe it had something to do with their ohm readings. I pulled one of the black ones from a JY vehicle.

But the knock sensors are useless for me. I get thousands and thousands of knock counts, even back when I had so little timing, a knock would have been impossiable. Changing ESC modules didnt help any. I kept them instaled, but had retard turned off and have made my whole timing map by ear.

[EagleMark]

You just have a noisy motor I guess. There was some testing by Grumpy and found the ESC made some differnces. I did read a paper about knock sensor placement in block and block metal resonence. Said placing in center of block closer to head was optimal. Duh! But never mentioned in water jacket where I think all GM sensors are?

[JeepsAndGuns]

I mounted the 7747 KS in the block coolant drain plug hole on the drivers side. The threads were the same as the plug that was originally there. Its kinda low and centered.
The black one I pulled from the junyard had longer regular threads (not pipe threads) and was in a head. So I put it in a un used hole in the block closer to the front of the engine, still on the drivers side. No diffrence in knock counts when I went to that KS and the 7427. Mabey one day I will play with diffrent locations.

[EagleMark]

Head is suposedly bad spot. What car had it there?

Wonder what would happen if you mounted 2 knock sensors? One on each side of block? Probably mess up reading but could change wire from one to other to see if one side is knocking or producing less noise so knock works better?

[gregs78cam]

My Camaro has crazy knock counts when cold due to the forged pistons, and at certain rpm when warm I think due to the link bars between the roller lifters, you can actually hear them under the manifold at an idle.

[93V8S10]

Head is suposedly bad spot. What car had it there?

Wonder what would happen if you mounted 2 knock sensors? One on each side of block? Probably mess up reading but could change wire from one to other to see if one side is knocking or producing less noise so knock works better?

A 4.3 Memcal uses two sensors, if you want to have two going all the time.

Knock sensors on my engine are worthless, due to cheap roller rockers.

It's the black one, you need for the V8 Memcal or two of them for the 4.3 Memcal.

[jim_in_dorris]

93, are you saying that cheap roller rockers cause knock sensor problems? HMMMM I was looking at a set of full roller stainless rockers for my rebuild, maybe I should rethink that.

[93V8S10]

93, are you saying that cheap roller rockers cause knock sensor problems? HMMMM I was looking at a set of full roller stainless rockers for my rebuild, maybe I should rethink that.

To be honest, I don't really know exactly why I can't get a knock sensor to work with my engine. At this point, I have assumed the rockers to be the culprit.

[EagleMark]

A 4.3 Memcal uses two sensors, if you want to have two going all the time.

Knock sensors on my engine are worthless, due to cheap roller rockers.

It's the black one, you need for the V8 Memcal or two of them for the 4.3 Memcal.

Are you saying this could be incorerated into a V8 16197427 built EFI system?

My LT1 has 2 knock sensors and the knock module is built into PCM. Thread with pictures in this forum. I was wondering if that module could be incorperated as some have used it in TPI ECMs.

Interesting!

[93V8S10]

Are you saying this could be incorerated into a V8 16197427 built EFI system?

Maybe, remember I don't have a working knock system. I do have a 4.3 Memcal with two sensors that are hooked-up. You would have to experiment.