Is any knock bad??

[wickedmotorhead]

Hi guys,

I'm new to all this. I just got an 1987 Grand National and I have been watching my Scanmaster for knock since I got it and it always shows 0.0, UNTIL today after I hit it a little I was showing anywhere from .4 to 5.0 even afterwards during normal driving. What does this mean and should I be concerned?

Any help is greatly appreciated. Thanks.

Shane

 

[TurboSlacker]

It depends when the knock is occuring. Sometimes at tranny shifts it may record a knock reading then go back to zero. It could be other external mechanical knock rather than the more serious internal combustion knock caused by detonation. So we need a little more info to help out further.

What boost level?
What gear was the knock?
What mph was the knock?
What's the timing setting in your chip?
What octane level of fuel? Alky injection?
What's your combo?

I tune my car on the street to run less than 4 deg of knock at WOT in 4th gear near 100-110mph. This results in no knock in 3 gear thru the traps at the track.

Basically you want to fine tune your car (boost, timing) to the point where you start to see a couple degrees of knock then back off a touch to run near zero knock for regular street driving.

 

[GrndNatnl]

Where in the heck to you live where you're running out 4th gear to 100 + mph on the street?? If I went out to tune my car and did that around here, I would either plow into someone or something in the insane amount traffic, or I would be locked up, and my license would be in the damn court house trash can.