885 lifters and knock sensor

BEATAV8

The Engine Whisperer
Joined
Feb 14, 2002
Anybody running comp 885 lifters with a knock sensor?

Have a stock ECM car here with some false knock and looking for sources. Looking for any experience / comments regarding the 885 lifters and false knock.

thanks!
 
Steve, I ran them for a few years with no problems. Now I'm running solid lifters. No problems with them either.
 
Sensor torque has been tested at loose, really loose, and next will be tested at ridiculously loose (hand tight) with lots of teflon tape on the first few threads.

Car is showing KR activity (blips) during normal driving, when releasing the throttle, etc. It also has casper knock gauge and audible installed.
 
valvetrane sounds good, can discern from the sound that it's got the 885's in it as it has slightly more sewing machine action going on compared to an engine with 853's. But still sounds very nice.
 
Have you tried to adjust the lash on the valves? if so, what settings are you using? Lastly, what kind of oil are you using in the motor?
 
..............Car is showing KR activity (blips) during normal driving, when releasing the throttle, etc. It also has casper knock gauge and audible installed.

Years ago I had that issue on a GN, when I disconnected the boost gauge and alarm, false KR went away?
 
Have you tried to adjust the lash on the valves? if so, what settings are you using? Lastly, what kind of oil are you using in the motor?
Valve lash was initially set and then re-checked after de-green, not by myself so I do not have any numbers. Oil is 20W50 VR1.

thanks
 
Years ago I had that issue on a GN, when I disconnected the boost gauge and alarm, false KR went away?
did you mean knock gauge or boost gauge?

owner and I have been discussing removing both the knock alarm and the knock gauge from the vehicle.

thanks
 
Will go through the process of checking ESC wiring and grounding, terminal quality / corrosion, etc....
 
Been running with them for over 10 years various engines


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My opinion on knock sensors & someone feel free to correct me if wrong . Knock sensors work the best with stock or mildly built engines. Once you go over a certain thresh hold like roller cams forged racing pistons with looser crank clearances etc. now you have a lot of internal noise & harmonics that can aggravate a knock sensor basically tuned to stock frequencies. In this case and if you have a known safe tune correct timing and A/F I'm going to stick my neck out by saying disregard what would be considered false knock or continue to drive ones self nuts .
 
My opinion on knock sensors & someone feel free to correct me if wrong . Knock sensors work the best with stock or mildly built engines. Once you go over a certain thresh hold like roller cams forged racing pistons with looser crank clearances etc. now you have a lot of internal noise & harmonics that can aggravate a knock sensor basically tuned to stock frequencies. In this case and if you have a known safe tune correct timing and A/F I'm going to stick my neck out by saying disregard what would be considered false knock or continue to drive ones self nuts .

Fair enough.

How does the false knock effect the EMC and how it delivers fuel and spark and does it even effect performance?

thanks
D
 
..............How does the false knock effect the EMC and how it delivers fuel and spark and does it even effect performance?...........D

It is important to determine if the car has false knock or is it real?

Knock false or real will affect performance.

I have replaced a few head gaskets for free over the years checking to see if it is false knock or real, so my first step is to add some race gas to the tank to determine if there is a fuel delivery or octane issue?
 
It is important to determine if the car has false knock or is it real?

Knock false or real will affect performance.

I have replaced a few head gaskets for free over the years checking to see if it is false knock or real, so my first step is to add some race gas to the tank to determine if there is a fuel delivery or octane issue?

this one is showing random counts and retard blips when driving around under vacuum (with E85). confidence is high that it's a false knock issue. we'll get to the bottom of it though.
 
The easiest way to desensitize the knock sensor is to mount it on a short 2" pipe nipple. Need a coupler on the top end for the sensor to thread into. I did this as random false knock was prevalent. Then manual shift down to 2nd and the reported knock was continuous due to the high line pressure and pump noise.

I check the plugs for signs of real knock.

The knock filter (ESC module) is the brains of the system. It uses two methods of detecting knock to be reported. Enough of a magnitude within a certain frequency band will be reported.

And the one that usually sets off false knock is if the filter detects a sudden change in the overall frequency of any engine noise. This is why spinning tires, an automatic transmission down or up shift will set off this report. Exhaust rattle, cracked, broken or loose accessory brackets will also do it. Bad bearing in an accessory will also do it.

Reported knock won't affect the ECMs delivery of fuel. But it will cause the ECM to pull spark advance which kills power. IIRC, the stock ECM can also reduce the boost with enough knock being reported.

RemoveBeforeFlight
 
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