I have a 396LT4 with 9.0:1 compression, good quench, and 92 octane fuel.

It will not ping no matter how much timing I dial in.

Could it be that this motor won't detonate on too much advance alone?

 

How do you know it's not pinging? An engine will only ping under load. A computer controlled engine will detect ping (knock) and automatically retard the timing. If everything is working properly, you'll probably never hear a ping and will only notice a slight lack of power.

Now if you're using a scan tool to watch for any pinging that's a differnet story.

My engine burns alcohol. Even with 13:1 compression I can have my timing far advanced and it won't ping.

 

Yes, I was logging and saw no detected ping or retard. Even at 35, 40, 50, and 60 degrees total advance.

It was obviously losing power the more I went, but I wanted to see how far before it would knock, and it never did, and I thought that was weird!

 

If you think about how an internal combustion engine works, you will eventually reach a point where the spark really isnt doing anything. I am surprised your motor even ran with that much timing.

 

Keep messing with it and you will fu%% up the motor. Hope you have not made any runs with all that timing.

 

Really? How? Exactly how will too much timing with no detonation harm the motor, oh wise one?

 

Even if it does not audibly ping it's running too hot and you are going to burn stuff inside. I saw it happen on a Procharged LT1 WS6. You eventually burn head gaskets.

 

I know you arent talking to me but to add to this, you are eventually going to reach a point where you you are sparking before the intake valve has even closed, so any cylinder pressure made is going to be blown back up the intake. That is why a lot of times when someone tries to start a car with too much advance, if their starter will even turn the motor over, that you get those narly flames coming out of the carb/tb.

 

I'm kinda wondering if the advance you think you're setting the engine to is actually advancing? Maybe it's not changing at all hence no pinging.

 

Good point Steve.

 

Yeah...can't imagine advancing the timing that severely, without the consequences of your actions showing up on a logger. Either way, it's not a grand idea to push the envelope that way, as mentioned above.

 

Are you doing all this with the stock LT1 PCM? How are you changing timing? What are you using for data logging?

 

I had a buddy in college that drove a 3rd gen with DFI, and swore up that the 50* of total timing he ran produced the most power and was safe... I didn't see how he was getting away with so much timing, but he insisted it would be fine (couldn't hear any knock). Anyway, I was helping him do an oil change a few weeks later and came across something rather interesting... the magnetic drain plug was covered with large chunks of piston rings! He's now a mechanical engineer for ford doing engine calibration of all things.... guess he knows better now!

 

And I wondered why my F-150 pings on 87 octane.........?