X-Mozilla-Keys:                                                                                 
Vance and Emily Jaqua wrote:

For what it might be worth - I have had two
experiences which we later attributed to high speed
detonation. One nice and safely in an automobile
with spark plugs of the wrong heat range, and the
other a friends experience with a VW conversion with
too high compression ratio. The symptoms were very 
similar NO AUDIBLE Warning, and power loss that
was almost like switching off the ignition. 

Was that because it was in an airplane and the prop
noise masked the noise from the detonation? When
my hearing was good and the engine was not encased
in modern sound proofing I could always hear
pinging or detonation. My wife can hear it in the
real quiet Cougar. The knock sensor amplifier is 
designed to bypass all other noise. The knock sensor
itself is designed to tune out other non-knock 
related audiable frequencies.

Backing
down on power seemed to "cool" it off and judicious
amounts of power were then available. Subsequent
examination indicated metal loss from pistons.
Invite comments on experience of others, and hope
that knock sensors are quick enough to keep you
out of those trees. Vance

The whole idea is to use these knock sensors to tune
the engine and set the boost. After doing this and
for some strange reason you get knock on takeoff
under unusual conditions and you are confronted
with trees and the knock causes an appreciable 
loss of power the knock sensor and amplifier may 
not save you. 

That is why I, like Klaus, do not recommend
it be connected to the ignition or boost controller.

Climb out is the mostly likely place for knock
to occur. Test on a real long runway or flat and clear
airport in the heat of summer.

Or even better build one of my cheap angle iron
dyno's (see the ACRE NL web site) and set everything
up on the ground.

It is probably better to let it knock until you gain
enough altitude to land safely.

BTW knock or detonation very rarely occurs in a normally
aspirated properly tuned  rotary. It is mostly a problem 
with highly boosted rotary engines.

Paul Lamar
 
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