knock, knock! Who's there?

[Grant Lenahan]

Lean typically leads to knocking.

Not to mention very high nitrous oxides and sometimes CO.

Running a little rich is preferable to a little lean, often. But you 
really want it running spot on - best for power, performance, the 
environment and your wallet - all at once!

Grant
On Jul 22, 2007, at 2:06 PM, Tess McMillan wrote:

> Right, I remember the vacuum pump; that sound was more "Audi-sounding"
> than the knock I am experiencing now. We removed the pump from my car
> about two years ago.
>
> This knock is happening at 3800 rpm, when the engine is working hard
> (more so going uphill, for example). But I think I remember when I 
> went in
> for my track inspection in April, they leaned me out a bit. It's been
> since about that time, maybe May or so, that I've started to notice 
> this
> issue.
>
> And to be completely truthful, on a daily basis I'm only commuting to
> school and back and with so much schoolwork I am not getting out to do
> Italian Tune-ups on the weekend.
>
> Thank you for the education, guys!
>
> Tess
>
> On Sun, 22 Jul 2007, Tony Hoffman wrote:
>
>> And, to add to that, because it's pre-detonation, it tends to hapen
>> more at lower RPM's or where the "dynamic" compression is higher. As
>> an engine turns faster, it actually pulls in less ari per RPM. This is
>> because the valves, intake system, exhaust, etc, is not a limiting
>> factor for airflow at lower RPM's. But, that becomes an impedence at
>> higher RPM's. Which is exactly where bigger cams, bigger exhaust, high
>> flow air intake systems, ported heads, etc all come in.
>>
>
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