This is for my '35 Ford, 97 LT1. I have Sanderson block hugger headers supposedly LT1 specific but the collector on the header comes out right at the knock sensor. Can the sensor be relocated else where in the block? Maybe to the other side where the earlier LT1's have the oil pressure sensor? Any other ideas? I don't have the car nearby right now so I can't take another look at it. Thanks

 

Should be just fine. Theres a 1/4" NPT hole on the other side in the same spot. Some vehicles had 2 sensors and used this hole too.

 

that sounds good. It would be nice if there was a spot on the same side so the wire doesn't have to be made longer, but as long as it doesn't matter where the sensor is to read properly I'll probably just move it to the other side.

Any other options or confirmations?

 

I just had a thought. If I put it in the same place on the other side I'll have the same exact problem so I could put it above the oil filfter, right?



I almost put the oil pres. sensor there, but left it up top to not have to fool around with getting it by the steering, but I can make the knock sensor fit there if it will work.

 

It should work there too, but the signal might be weaker if you move it further away from the cylinders.


You can test the signal yourself to a degree by simply using an LED. Hook the LED to the sensor wire and ground (polarity doesn't matter). Then tap the block with a metallic object and the LED will flash. You can see the LED flashes dimmer the further away you tap the block (i.e. the other side of block). Try new locations and compare to the factory location.


On the side opposite of the factory location there is a boss at the top of the block that isn't threaded but is the correct size for a 1/4" NPT tap. There's also an unused motor mount boss toward the front of the block.

 

The knock sensor is in the water jacket, exposed to coolant. Putting it in the oil pressure port is going to fill it with viscous oil, dampening the response of the piezo microphone, which is tuned to specific frequencies. It may also pick up noise from the oil pump. Use the block drain hole on the driver's side.

 

Understood Fred, but if the drain plug on the drivers side is in the same location as the passenger side I think it still won't clear not to mention the steering on that side. In my search I found some people edit out the knock sensor, but I'd rather not. It sounds like those are my only options though?

 

Your other option would be to delete the knock sensor. I don't run one. But I always use the EXACT fuel that the engine was tuned for - whether its running NA or with the 300-shot.

 

Editing it out is an option. I have to double check and see how much clearance I need, but is it a possibility to add a 45* fitting with a ~1" length fitting and angle the sensor off, out of the way or should that affect the reading having to travel through all the fittings?

 

I called Sanderson and they said I could exchange that side for a shorter header, but he also said there is two ports in the water jacket on the drivers side...any truth to this? Again my car is not in the area at the moment.

He also said there are a couple places in the intake manifold that I could move the knock sensor, but I couldn't follow where on the phone. Anywhere come to mind up there? I am putting my temp gauge in the steam line so could it maybe go in the drivers side head?

 

I don't know if there is a second block drain plug on the driver's side. The fittings would decrease the sensitivity, although the main path to the microphone would still be the coolant. The head would probably alter the way the sound carries slightly, since its aluminum rather than cast iron.

 

Try the LED test with the sensor in the head. See if there is any "microphone" signal attenuation compared tot he stock location.

Also, I burned out an LED. Scoped the sensor and tapped it with a wrench and it was producing AC peaks of over 10 volts, so a rectifier diode should be used in series with the LED as the peak inverse voltage rating can be exceeded.