885 lifters and knock sensor

[bison]

At close to Zero lash do you have any issues with knock sensor going off ?? Do you run the knock sensor on your HP builds?

Valvetrain noise isn't usually in the range of most knock modules. I run knock sensors on over 90% of engines since most are 93/alky. On really high power applications with race fuel I've yet to ever see knock retard even when the esc is 100% stock. Just because there's not knock retard doesn't mean your in the safe zone. It's very possible to overheat cylinder without detonation.


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[David Husek]

Anybody running comp 885 lifters with a knock sensor?

I have not experienced any issues with 885 lifters making noise to create false knock or have I had any of my new design 885 lifters have an issue either. None of my customers have ever mentioned anything except for this inquiry. Lifters usually are not picked up by a knock sensor. Wrong frequency.

When using 885's, they are designed to have a set preload at .030" +- .010". For best results when using an 885 racing lifter, you want the preload at full engine temp to be between .001" and .005". Cold may be around .025" depending on the block and head combination being used due to expansion rates of each component. To many variables here to give an exact preload for each engine. I suggest manufacture preload for each engine combo. If you get negative preload, the seat can break on the lifter which will cause noise and possible failure.

Try running 10w30 also.

 

[BEATAV8]

Thanks Gents.

To me the consensus appears to be that the valvetrain component selection is an unlikely source for this vehicle's issues.

Ongoing investigation from here will focus on the electrical/physical condition of the ESC circuitry and other (typical) sources of false knock.

 

[Xflatrater]

Correct, my 855's are annoyingly loud but do not trigger ecs

 

[EVIL]

Have you run race fuel like suggested?

I was having the same issue and ran 110 unleaded, and still had knock at 20 psi.

I did fix a downpipe rubbing issue and it didn't help.

Car runs strong and sound and there is no metal in oil some so god only knows what it could be.

I quite enjoy these sort of threads. Learning about something I love is always a pleasure.

D

 

[DoubleD]

I am very personally interested in this, as my car will randomly record knock cruising around and chirp the audible alarm. I also get a little knock at shifts. I've usually attributed to converter and ignored it, not necessarily wisely. I have not cut the audible alarm out yet... Curious if it will fix it.

Let us know if you pinpoint the smoking gun. I was going to ask you about it at the last show, forgot.

 

[BEATAV8]

Have you run race fuel like suggested?


D

E85

 

[BEATAV8]

Lol well gents this car is fixed now. We cleaned off all the teflon tape on the knock sensor threads and installed the sensor at a healthy 14 ft*lbs and all issues disappeared. She works as she should now.

I think it's the first time I've heard of a knock sensor being too loose and causing false knock?

 

[Jerryl]

It may have been a grounding issue due to the tape. (??)

 

[BEATAV8]

It may have been a grounding issue due to the tape. (??)

Yes, very likely poor grounding due to the teflon tape and "looseness".

 

[Turbo6Smackdown]

Then why does everyone say use teflon tape?

 

[BEATAV8]

Then why does everyone say use teflon tape?

it's always been a common way to "dumb down" the knock sensor. I didn't remove the tape thinking that it was going to fix this car. My intent was to install the sensor per spec (clean and 14 ft*lb) and then see how bad this car was going to behave and hopefully make any source of false knock easier to find. Instead it fixed the car.

 

[Turbo6Smackdown]

So then did you just blow out the teflon tape theory?

 

[BEATAV8]

So then did you just blow out the teflon tape theory?

that is entirely up to the reader to decide

 

[Turbo6Smackdown]

Dam, I'd love to try that because I think I wrapped mine last year, but I think my transmissions's going lol.