Intake valve deposit

Insulin permeation rate, 9 69 Intake valve deposits (IVD), 12 409—410 Intake valve detergents, 12 409 Intalox saddles, 1 28 8 770... 

Deposits on intake valves are also caused primarily by olefins, especially diolefins, and higher-molecular-weight aromatic fuel components. The higher temperatures within the intake valve region promote the formation of deposits which are more carbonaceous than those which form on fuel injector tips. Also, components of the lubricating oil additive package are often found within the matrix of intake valve deposits. 

Intake valve deposits (IVD) vary in appearance and character. Some are hard, dry, and crusty some are relatively soft and thick while others are thin and vamishlike. They can form on valve tulips, valve stems, and on valve seats. Poor starting, warmup, and initial acceleration are common symptoms of an IVD problem. 

Fuel injector and/or intake valve deposits may be present in gasoline engine... 

Mikkonen, Seppo, Aapo Niemi, Markku Niemi, and Jorma Niskala. 1989. Effect of engine oil on intake valve deposits. Report No. 89211. Warrendale, Pa. Society of Automotive Engineers. 

Expecting the EPA to lower the IVD value in the future, we were asked by Lubrizol to design a fuel additive for an intake valve deposit of 10 milligrams. We used a genetic algorithm in the hybrid model (see Figure 9.2) to predict the properties of some designed molecules. 

Surfactants are used in fuel applications to prevent fuel injector deposits, intake valve and exhaust valve deposits, combustion chamber deposits [2,3], injector deposits of direct gasoline injector systems [4,5] and high-pressure diesel injector systems [6], and low-temperature intake valve deposits [7]. 

Additives are an essential component of finished fuels. They increase stability, improve flow properties and enhance performance. For example, cetane-improvers are routinely added to diesel fuel, and additives that prevent intake-valve deposits are now required in all grades of gasoline in the United States. 

In fact, ethanol fuel mixtures can reduce the formation of these intake valve deposits, but such a remediation typically shifts the problem to the combustion chamber, where unacceptable combustion chamber deposits are then formed. Therefore, an additive is needed which upon combustion will effect in the engine a significant reduction in the intake valve deposits and simultaneously effect a reduction of the combustion chamber deposits in the engine. 

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