Technical Information

Knocking, Pre-Ignition, and Detonation

Distributed By: Syntek Global Inc. 12382 South Gateway Park Place Suite B800 Draper, UT 84020 801-386-5007

Knocking In spark-ignition internal combustion engines, knocking occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture combust outside the envelope of the normal combustion process. The air/fuel charge is meant to be ignited by the spark plug only, and at a specified time during the normal cycle of the piston. The peak of the combustion process no longer occurs at the optimum moment in which the air/fuel mixture was intended to ignite. The shock wave creates the characteristic metallic “pinging” sound, and cylinder pressure increases dramatically. Effects of engine knocking can be significant. However, it should not be confused with pre-ignition as the two are separate events. By design, Xtreme Fuel Treatment responds to the normal combustion process by advocating combustion at the precise time in which combustion should occur. Xtreme Fuel Treatment helps to create catalytic ‘zones’, which optimizes the results of the combustion process. This process results in the elimination of the random spark ignition that creates knock, and which deprives the engine of performance and fuel efficiency. Xtreme Fuel Treatment will minimize knock sensor activity on all modern day engines.

Pre-Ignition In a spark-ignition engine pre-ignition is a technically different anomaly from that of engine knocking. “Pre-ignition” describes the event wherein the air/fuel mixture in the cylinder ignites before the spark plug fires. Pre-ignition is initiated by an ignition source other than the spark, such as hot spots in the combustion chamber, a spark plug that runs too hot for the application, or carbonaceous deposits in the combustion chamber heated by previous engine combustion cycles. One of the signs of pre-ignition is run-on or “dieseling” as it is sometimes referred to in carbureted engines. This event causes the engine to continue to run after the ignition is shut off. “Dieseling” refers to the fact that a heated diesel engine may, by design, run without an external ignition trigger so long as a suitable fuel/air mixture is supplied to the cylinders. This effect occurs most often in carbureted gasoline engines, as the fuel supply to the carburetor is typically regulated by a mechanical float, needle and seat. As such, fuel delivery can feasibly continue until fuel line pressure has been relieved, provided the fuel can be evacuated past the carburetor throttle plate. The occurrence is rare in modern engines with throttle-body or electronic fuel injection, as the injectors will not be permitted to continue delivering fuel after the engine is shut off, and any occurrence may indicate the presence of a leaking (failed) injector. Preignition and engine knock both sharply increase combustion chamber temperatures. Consequently, both effect increases the likelihood of the other effect occurring, and both can produce similar effects from the operator’s perspective, such as rough engine operation or loss of performance due to operational control intervention by a power train management computer. For reasons like these, a person not familiarized with the distinction might describe one by the name of the other. Xtreme Fuel Treatment is designed to remove carbonaceous buildup from the combustion chamber. In a short period of time, Xtreme Fuel Treatment will catalytically re-involve solid carbon buildup during the normal combustion process, expelling the sub-micron carbon particles through the engine exhaust. Thus eliminating retained heat zones that can, and will create pre-ignition sites throughout the combustion chamber. Carbon buildup is not redistributed throughout

Knocking, Pre-Ignition, and Detonation

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the engine; it is in fact evacuated from the engine. Moreover, reductions in retained thermal heat, and improved combustion at the time of ignition do in fact reduce thermal engine temperatures as much as 400° F., which once again helps to minimize the effects of pre-ignition.

Detonation When unburned air/fuel mixture beyond the boundary of the flame front is subjected to a combination of heat and pressure for certain duration (beyond the delay period of the fuel used), detonation may occur. Detonation is characterized by an instantaneous, explosive ignition of at least one pocket of air/fuel mixture outside of the flame front. A local shockwave is created around each pocket and the cylinder pressure may rise sharply beyond its design limits. If detonation is allowed to persist under extreme conditions or over many engine cycles, engine parts can be damaged or destroyed. The simplest and most devastating effects are particle wear caused by moderate knocking, which may further ensue through the engine’s oil system and cause wear on other parts before being trapped by the oil filter. Severe knocking can lead to catastrophic failure in the form of physical holes punched through the piston or head, either of which depressurizes the affected cylinder and introduces large metal fragments, fuel, and combustion products into the oil system. Once again, Xtreme Fuel Treatment helps to create enhanced combustion sites throughout the combustion chamber. These sites promote combustion at the point of ignition, which dramatically reduce random fuel ignition and cylinder pressure. Xtreme Fuel Treatment is especially effective in older engines, where years of use and carbon buildup have robbed the engine of efficiency and power. In fact, the use of Xtreme Fuel Treatment has been proven to increase the longevity of engine oil by reducing carbon impurities introduced to the oil by normal engine blow by. The science behind Xtreme Fuel Treatment has been evaluated for many years at the most stringent, regulated laboratories throughout the United States and in other parts of the world. These evaluations include engine wear tests; federally approved FTP and HFET test procedures. Further evaluations have been conducted utilizing SAE test procedures. At no time, has Xtreme Fuel Treatment Fuel Treatment proven to damage any components related to an internal combustion engine, including the newer electronic fuel controlled engines. Xtreme Fuel Treatment will not affect engine compression ratios or alter any mechanical engine design. It will not re-distribute carbon buildup to cylinder surface irregularities. Electronic fuel injection parameters are not altered to increase or decrease fuel flow. Xtreme Fuel Treatment Fuel Treatment merely improves the combustibility of the fuel injected into the combustion chamber. Improved fuel ignition reduces heat and engine strain due to a more rapid release of energy, which in turn produces consistent pressures throughout the combustion process. Xtreme Fuel Treatment helps to improve fuel energy release, which reduces the need for fuel volume. In short, Xtreme Fuel Treatment will provide a means wherein more work is extracted with the need for less fuel.

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