Pinging Info. from Amsoil (LONG)

From: Bob Tom (tigers@bserv.com)
Date: Thu Oct 28 1999 - 17:46:15 EDT


Below is part of an Amsoil newsletter about pinging and
Amsoil's gasoline additive to combat it. I am NOT in any way
associated with Amsoil. I decided not to paraphrase their
marketing literature and let anyone interested decide for
him/herself. My view is that if you've tried almost everything
and everyone is still stumped, it will cost only a bit of $$$
to see if their additive will eventually work.

I'm fortunate (fingers crossed) in that I have not had any
pinging problems since I bought the Dak in Feb. '97.

Last 8 paragraphs are when they talk about the additive.
I found the prior paragraphs informative with respect to
the causes of pinging.

WHAT EXACTLY IS ENGINE KNOCK?

Let's look first at normal spark-ignition combustion. Each
injector sprays a charge of gasoline into its cylinder when the
piston is at bottom dead center. The piston rises, compressing
the gasoline-air mixture, which causes the temperature of the
mixture to rise. At a defined point, the spark-plug sparks,
which causes the gas-air mixture to burn from the point of the
spark out to the edges of the cylinder. The energy released by
the controlled flame front pushes the piston down, which turns
the crankshaft and powers the engine.

Knock occurs when the gas-air mixture spontaneously combusts
prior to spark ignition or at a location away from the flame
front. Combustion chamber deposits often cause this problem.
Those spots of uncontrolled combustion act like tiny bombs,
spreading shock waves and heat. Extended periods of uncontrolled
knock is highly destructive. Retarding the timing of the spark
reduces cylinder temperature, which inhibits the uncontrolled
combustion and knock.

But retarding the timing also establishes the flame front later,
so the energy released by combustion "chases" the piston down
instead of pushing it down. In other words, much of the energy
of combustion goes unused. That's why your car goes into slow
motion when the knock sensor kicks in. The knock sensor is most
likely to kick in when the engine temperature rises-like when
you're going uphill, passing and driv-ing in hot weather.

----------------------------------------------------------------

KNOCK SENSORS, FUEL ADDITIVES AND OIL SLUDGING

We've all been there. You're driving along in heavy traffic with
a hot sun beating down and you're stuck behind some huge
rattletrap crawling uphill in second gear. You spot a tiny
opening in the next lane and make your move. But your car's get
up and go has got up and left, and you're crawling up the hill
no faster than the ancient truck you intended to pass. What
happened?

Your knock sensor kicked in, that's what. More than half the
cars sold in the U.S. are equipped with knock sensors, which
retard timing when gasoline octane isn't high enough to allow
the engine to perform the task it has been asked to perform,
such as passing or going uphill or going anywhere in high
ambient air temperatures. Retarding the timing of ignition
protects the engine from knock.

Most drivers are used to hearing the ping of knock, and not used
to recognizing knock as the drop in power, responsiveness and
performance that comes with knock sensors. But if you drive a
newer model car, and you experience poor performance, think
"knock", even if you don't hear the tell-tale ping. Your knock
sensor simply adjusted the timing before you heard it. What can
you do to protect your engine from knock and maintain the power
and performance you desire?

At first, you'd think the answer would be higher octane fuel.
And, although it may improve performance, it may also be an
unnecessary drain on your pocketbook. Additionally, higher
octane fuel will not solve your problem if your engine knock is
caused by deposits. You see, octane defines a gasoline's
ignition point in a perfect world, with low octane gasoline
igniting at lower temperatures and pressure than high octane
gasolines do. But in the real world, deposits create hot spots
that cause gasoline — of even the highest octane — to ignite
prematurely and knock. Intake valve deposits soak up fuel like
sponges, which disturbs the precise air-fuel ratio, again
leading to poor performance and sometimes knock.

But wait a minute. Isn't gasoline treated with detergents to
control fuel system deposits? It sure is. But only at a treat-
level that controls severe driveability problems, not garden
variety knock. In fact, deposits begin forming immediately even
with refinery-treated gasoline. The only way to combat them is
with additional gasoline treatment.

That's why motorists need AMSOIL Performance Improver Gasoline
Additive. Performance Improver (PI) inhibits the tendency of
gasoline to form fuel system deposits. Nothing works better — or
safer — than AMSOIL PI.

What makes PI better than other gasoline additives? PI keeps
the entire fuel system clean, from combustion chamber to fuel
injectors or carburetor. Clean injectors and carburetors deliver
their full load of gasoline in a fine spray. The full load of
gasoline keeps the gasoline-air ratio from becoming too lean,
that is, too much air for the amount of gasoline available. When
combustion occurs in an environment with too much air, the
combustion event is hotter than it would be in an environment
without excess air. That heat encourages knock. By keeping
injector orifices clean, PI allows delivery of a full charge of
gasoline to the combustion chamber.

The fine mist of gasoline ensures a pattern of uniform small
gasoline droplets. The smaller the fuel droplet, the more
readily and fully it combusts, which also aids performance and
inhibits knock.

Here's an added bonus. The more readily and fully the gasoline
combusts, the lower the exhaust emissions and the better the
fuel economy. Many grateful PI users have written to say that PI
helped them pass emissions tests, saving them money on fines and
repairs.

What about safety? Aren't all fuel system additives alike? They
are not. Some contain chemistries that, even at low treat rates,
cause motor oil to sludge and thicken. In fact, recently, oil
companies, testing facilities and fuel and oil additive makers
have put two and two together and realized the sporadic cases of
oil sludging and thickening they've been seeing for the past few
years have been caused by gasoline additive chemistries. Some of
the very severe cases of oil sludging and thickening led to
engine failure. Gasoline fuel additive and motor oil
compatibility is a serious issue. Don't risk your engine!

AMSOIL PI uses a chemistry that's been proven compatible with
motor oil through extensive testing and billions of on-road
miles. It's been on the market and continuously upgraded for
more than two decades. There's no question about its safety when
used as directed. Just remember, more is not always better, and
this applies to AMSOIL PI

It's a safe bet you'll love the power and performance you get
with AMSOIL Performance Improver.

You can order AMSOIL PI in 16 oz. bottles which will treat up to
160 gallons of gasoline for $7.85. Simply use the link below:

https://kookiejar.net/~goesecure/web_store/quikstore.cgi?keywords=PCV

Bob. Southern Ontario, Canada.
'97 FR CC Sport, 5.2L, 3.55 SG, auto.
Racing weight: 4,350lb ET: 14.934 Trap speed: 90.78 mph



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