Browse Topic: Octane

Items (73)

A comparative study of ethanol and methanol blends on performance and emissions on BSIV and BSVI class of vehicles

2024-26-00731/16/2024

The quest for alternate fuels has led many researchers to evaluate various alcohols as an immediate substitute for gasoline. Among the alcohols, ethanol has received a lot of popularity as it can be produced from biomass feeds such as sugarcane and corn. Several countries have made it mandatory to blend at least 10% of ethanol in gasoline. However, the source of feedstock for ethanol production is posing a threat to food security. In order to restrain this problem, a few countries are promoting the use of methanol as an alternative fuel. Methanol can be obtained by processing naturally available biomass resources, much of which is waste material. Methanol-gasoline blends have been found to have a high octane number, good performance and lower carbon emissions, making it an excellent alternative fuel for engines. In the present study, a comparative analysis was carried out to evaluate the performance and emissions from unmodified vehicles using lower concentrations (up to 20%) of

Teja, Ravi, Khandai, Chinmayananda, Muralidharan, M

A prediction model of octane number loss based on neural network

2022-01-01813/29/2022

The octane number is the most important indicator of motor petrol, and the petrol refining process is one of the important links in petrol production. The prediction of the octane loss number of petrol during the refining process is helpful to the improvement of petrol refining process and the processing of petrol. The traditional octane number prediction method relied on physical and chemical properties, and did not fully consider the high nonlinearity and strong coupling relationship of the petrol refining process.There is a lack of data-driven octane loss models. This paper studies the construction of the octane loss model in the petrol refining process. The main innovation is to use frequency statistics to summarize the operating range of data variables and preprocess the dataset, and use the variance selection method to filter out some invalid variables, then use the multi-dimensional association analysis to select 27 main operating variables in the next step. Finally, a neural

yang, Gang, Zhang, Sumin, Li, Shuai, Li, Wenju

Direct Measurement and Chemical Speciation of Top Ring Zone Liquid During Engine Operation

2015-01-07414/14/2015

The present manuscript consists of proof of concept experiments involving direct measurements and detailed chemical speciation from the top ring zone of a running engine. The work uses a naturally aspirated single cylinder utility engine that has been modified to allow direct liquid sample acquisition from behind the top ring. Samples were analyzed and speciated using gas chromatographic techniques. Results show that the liquid mixture in the top ring zone is neither neat lubricant nor fuel but a combination of the two with unique chemical properties. At the tested steady state no-load operating condition, the chemical species of the top ring zone liquid were found to be highly dependent on boiling point, where both low reactivity higher boiling point fuel species and lubricant are observed to be the dominant constituents. The results show that at least for the tested condition, approximately 25% of the top ring zone is comprised of gasoline fuel like molecules, which are dominated by

Splitter, Derek, Burrows, Barry, Lewis, Sam

ERRATUM: An Investigation of Cascading Autoignition and Octane Number using a Multi-zone Model of the CFR Engine

2011-01-0850ERR8/15/2012

The equation found on page 994 contains errors and is corrected in the erratum.

Perumal, Marlan, Floweday, Gareth

A new method to simulate the octane appetite of any spark ignition engine.

2011-01-18738/30/2011

The octane appetite of an SI engine can be expressed in terms of an Octane Index: OI = (1−K) RON + K MON where K is a constant for a given operating condition and depends only on the pressure and temperature variation in the engine (it is not a property of the fuel). Experimental measurements of K values can be costly and time consuming. This paper reports the development of a new K-value simulation method that can be applied to any spark ignition engine given basic engine data. Good agreement between simulation and experimental results suggests the method is reliable and can be applied to a wide range of engines.

Davies, Trevor J., Cracknell, Roger F., Head, Bob, Hobbs, Kathryn, Riley, Timothy

A Fleet Test Evaluation of the Effect of a Unique Gasoline Additive on Octane Requirement Emissions

This paper describes a 30 vehicle test conducted to evaluate the performance of a new gasoline additive technology. The technology consistently demonstrates an ability to control octane requirement increase of automotive engines, and even effect a reduction, under standard dynamometer stand conditions. The objective of this work was to determine if a beneficial influence, relative to unadditized base fuel, on the octane requirement of a broad fleet of typical customer vehicles could be observed. Included in this evaluation is an assessment of both octane requirement increase control (ORIC) and octane requirement reduction (ORR). Additionally, data regarding inlet valve deposits (IVD), combustion chamber deposits (CCD), emissions, and lubricant properties are included.

Haury, E. J., Graham, J.

Gasoline Properties Estimation from Hydrocarbon Clustering Classification

93274110/1/1993

A two-stage approach to properties prediction of gasoline blends is proposed. The first stage is a clustering classification of the hydrocarbon range from C1 to C12, using the physical properties and quantifiable molecular characteristics of each compound as classification variables. This classification divides each of the PONA families into several groups. In the second stage a sample of Venezuelan gasoline blends is used to build regression models with variables resulting from the clustering classification. The sample analyzed includes different gasolines within a wide composition range, lead antiknock additives and oxygenated compounds.

Llatas, Isabel, Saab, Leonardo

Octane Blending Values Calculated Through Gas Chromatography Data Based General Models for Venezuelan Gasolines

92221610/1/1992

In this paper a general model is presented for the prediction of octane blending values based on gasoline compositions containing Methyl Tertiary Butyl Ether. The models were fitted to data coming from design experiments for five Venezuelan refineries using data transformations and regression techniques such as stepwise model adjustments. The models eliminate to some extent the dependency of prediction on components (alkylates, naphthas, reformates, etc.). The regression variables are generated from detailed gas chromatography data for each component, depending on the response variable. The regression adjustments found were up to 94 % for research and 86 % for motor premium gasoline octane numbers. Regular gasolines had 92 % regression adjustments for research and 48 % for motor octane number. The residual standard deviations are 0.327, 0.529, 0.430 and 0.788 respectively. The models for unleaded gasoline require only compositional data of the components and apply over all the

Saab, Leonard, Llatas, Isabel

Use of Ethyl-t-Butyl Ether (ETBE) as a Gasoline Blending Component

90213210/1/1990

The U. S. Treasury Department recently ruled that the ethanol blenders tax credit applies to ethanol used to make ETBE for blending with gasoline. As a result, ETBE may soon become a popular gasoline blending component. Like MTBE, ETBE adds oxygen to the fuel while contributing to other performance properties of the gasoline. Phillips Petroleum Company has completed limited driveability and material compatibility studies on gasolines containing ETBE and has determined the effect on various performance parameters such as octane, volatility, and distillation of ETBE in gasoline. Levels of ETBE ranging from 0.0 to 23.5 volume percent (3.7 weight percent oxygen) in gasoline were included in the investigation. Use in gasoline is currently limited to only 12.7 volume percent (2.0 weight percent oxygen) by the gasoline substantially similar rule. No detrimental effects of the ETBE on metal or elastomeric parts common to gasoline delivery and fueling system were found. Also, several favorable

Shiblom, Clifford M., Schoonveld, Gary A., Riley, Richard K., Pahl, Robert H.

Some Features on Chinese Motor Gasoline

89119311/1/1989

In the last decade, the production of Chinese motor gasoline has been doubled, and the gasoline octane level has been significantly upgraded. However, China still produces approximately 70% of its total gasoline with a RON rating less than 90. Nowadays, the Chinese gasoline pool is largely composed of FCC naphtha, which comprises about 70% of the total gasoline production. The majority of refineries produce 90 RON gasoline containing nearly 90% FCC naphtha, whereas a few refineries produce 90 RON gasoline consisting of FCC naphtha only. As a result, Chinese gasoline differs from foreign gasoline in its high olefin content (mostly from 35 to 55 percent) with a high sensitivity ranging from 9 to 11, and its octane number declines from front to end in its full boiling range. In spite of its high olefin content, the induction period of gasoline is more than 480 min after dosing with anti-oxidant at the outlet of the FCC unit. The blending characteristics of FCC naphtha with other gasoline

Xichu, Wang, Xing, Zhang, Youhui, Wang

The Effect of Blending of MTBE in Gasoline on Octane Improvement

87126711/8/1987

There are two basic incentives in blending MTBE in gasoline for a country like Indonesia, i.e. to improve the octane quality and to reduce the lead content in gasoline. Changes in physical and chemical properties of gasoline will also occur, accompanying the improvement of the octane number. The blends used in this study were made in four concentrations, viz. 3, 6, 10, and 15 volume percent MTBE in unleaded gasoline. The test results were compared to the Indonesian specification of premium gasoline.

Mustafa, Bustani, Jasjfi, E.

Unleaded Motor Gasoline - A Quality/Quantity Survey of the European Situation

86158510/6/1986

Europe is currently on the threshold of introduction of unleaded gasoline. However, this will not proceed uniformly, as some countries such as Germany. Austria. Switzerland and now Scandinavia are moving much more quickly than others. In those countries where unleaded fuel is available, registrations of catalyst cars and the build-up of the gasoline retail network and sales volumes are described. Possible future developments in these areas are discussed. The potentials and limitations on the manufacture of unleaded gasoline are discussed together with the role of oxygenates. The development of specifications in various countries is described and on the basis of market surveys actual quality is compared with the minimum requirements of these specifications. Results of road tests are presented showing the effects of both gasoline with maximum lead content and engine oil with a relatively high phosphorous content on deterioration of catalyst efficiency.

Dabelstein, W. E. A., Reglitzky, A. A., McArragher, J. S.

Unleaded Petrol and Its Implications for the Australian Oil Industry

85218811/11/1985

In 1981 the Australian Transport Advisory Council recommended to the Federal Government that Australia adopt a nationally uniform policy requiring new passenger cars manufactured after January 1, 1986, be designed to operate on unleaded petrol and meet the equivalent of US 1975 emission standards. This paper describes the development of an Australian standard for unleaded petrol with particular relevance to the choice of key parameters such as octane rating, permissible lead content, sulphur and phosphorus content, and colour. It focuses on the major implications for the oil industry including the production of unleaded petrol to meet the standard, its storage and its distribution with particular reference to the changeover from leaded regular to the unleaded grade with nationwide supply by July 1, 1985. The implementation of new quality control procedures are described and future developments are briefly discussed.

Martin, C. L., Bennett, J. N., McNally, M. J.

Impact of fuel composition on octane requirement

Fuel composition can affect the octane requirement of a spark ignition engine. Three cars of one European model were run to 80,000 km on fuels containing 0, 0.15,and 0.4 g Pb/litre. Differences in octane requirement among the various fuels were found as the distance traveled increased. This paper also describes octane requirement differences after combustion chamber deposits were removed.

MARSEE, F J, SUNNE, J P, ADAMS, W E

A Study on Octane Requirement for Motor Vehicles in Indonesia

83093311/7/1983

The knowledge of the exact level of octane number required for the car population in a country is quite important both for the petroleum refiners and the consumers. If the actual gasoline octane number is too high, the use of a superfuous anti-knock represents a loss for the refiners; on the contrary, if the octane level is too low, knock will result and risks of engine damage may occur. Various factors affecting the octane requirement of the car such as engine design, atmospheric conditions, service life of the car are reviewed. The octane level needed could only be assessed by actual measurements on cars representing the various types of cars in the country. Two consecutive studies for the requirement of the car population in Indonesia were carried out in 1978 and 1982 respectively, are described, and the results of the measurements of both studies are expressed in octane requirement curves.

Kaslan, W., Batti, F.

The Phillips Small Sample Research Octane Number Method

The Phillips Small Sample Octane Number Method (Research) was derived from the ASTM method by replacing the ASTM fuel metering system with a low dead volume induction system injection pump and by replacing the analog signal processing equipment. The pump, signal processing, and fuel sampling are under computer control. Important features include direct comparison of each test fuel with primary reference fuels, signal averaging to enhance the signal-to-noise ratio, and frequency domain filtering. With a microprocessor-based system nine to ten routine determinations can be done each hour using less than 15 ml of test fuel. A more powerful computer should permit the rating of 25 to 30 test fuels each hour. Except for the time and fuel requirements the results from this method are comparable to those obtained with the ASTM method.

Childs, W. V., Vickery, E. H.

The Phillips Small Sample Motor Octane Number Method

The Phillips Small Sample Octane Number (SSON) Methods (Research and Motor) were developed from the ASTM methods by replacing the ASTM fuel metering system with a variable stroke positive displacement metering pump, the fuel selector valve with an automatic valve, and by using digital signal processing procedures. The pump, fuel sampling, and signal processing are under computer control. Important features include direct comparison of each test fuel with two primary reference fuels, signal averaging to enhance signal-to-noise ratio, and digital recording of the transducer output before processing. The transducer used is a standard D1 pickup which produces a voltage that is proportional to the rate-of-change of pressure within the engine cylinder. This report describes the application of SSON techniques to the determination of Motor octane Numbers (MON), and compares SSON results directly to ASTM results. The SSON method takes only six minutes and requires a twenty ml sample of test

Childs, W. V., Vickery, E. H.

A Theoretical Study of Engine Deposit and Its Effect on Octane Requirement Using an Engine Simulation

An engine model is developed which incorporates the physical effects of deposit. Engine octane requirements are calculated from the model’s unburned gas temperature-pressure tracks using a recent empirical expression for the autoignition delay of hydrocarbon-air mixtures. The computed octane requirement for the clean model engine is in reasonably good agreement with experimental values, as is the octane requirement increase (ORI) due to the increase in compression ratio caused by the assumed deposit. The computed ORI due to the thermal effects caused by the deposit is too low by a factor of approximately 3, however. Possible explanations for this unresolved discrepancy are discussed.

DeGregoria, Anthony J.

Developing Road Octane Correlations from Octane Requirement Surveys

We are often interested in predicting octane performance in cars as a function of Research and Motor octane numbers. Prediction equation parameters can be developed by regressing data taken directly from Coordinating Research Council reports on annual car octane requirement surveys. However, there is a major problem with these data. They are pooled in such a way that data points for different fuel series do not correspond to the same cars in each case. This paper presents a better method that makes use of Individual car data and also fuel data.

Ingamells, J. C., Jones, E. R.

A Device and Technique for Determining the Octane Requirements of Individual Cylinders of an Engine

80135310/1/1980

An electronic device was constructed which, when used with the breakerless transistorized ignition system now common on U.S. cars, allows the octane requirements of the individual cylinders of a multicylinder engine to be determined. Basically the instrument functions by retarding the spark timing of all cylinders except the one being rated. A detailed schematic diagram of the Selective Ignition Retard Device (SIRD) is included in the paper to allow construction of the unit by interested parties. SIRD has been employed in studies aimed at elucidating the factors affecting octane requirements of engines. Some typical test results are presented.

Graiff, L. B., Ehrhardt, W. M., Haury, E. J.

The Effects of Refinery Gasoline Components on Road Octane Quality

Thirty-five unleaded and nineteen leaded gasoline blends were tested for road octane rating in a fleet of nine unleaded cars or seven leaded cars as applicable. These blends were prepared to cover a wide range of composition while meeting octane targets and volatility specifications. Road octane results were closely related to (R+M)/2 for unleaded gasolines but Motor octane was more important than Research for leaded gasolines. The effects of component composition on deviations from road octane correlations were small. Unleaded component effects not predicted by laboratory octane number were obtained in a single manual transmission car; those effects are attributed to octane distribution over the gasoline boiling range.

Burtner, R.E., Morris, W.E.

Seasonal Octane Specifications

Petroleum marketers traditionally supply gasolines of constant octane quality year-round. However, car octane number requirements are not constant, but vary with atmospheric temperature and humidity. Adjusting octane quality to match seasonal changes in car requirements would result in less octane giveaway during periods of low requirements and would reduce gasoline manufacturing costs for the same year-round satisfaction. Because of problems with exchanges, contract sales, and pipeline fungibility specifications, application of seasonal octane specifications on a widespread basis is not feasible unless they are generally accepted by the industry.

Keller, B.D., Steury, J.H., Wagner, T.O.

Studies of Customer Awareness of Knock

The influence of driving procedures and extraneous car noise on perception of engine knock has been studied with late model cars. Year to year changes in reports of knock by both customers and raters and changes in octane requirements were also reviewed. Customers generally accelerated cars less vigorously and tended to perceive knock less often than raters. However, in cars that had maximum octane requirements at part-throttle, customers perceived knock about as frequently as raters. Octane requirements, as determined by raters, were reduced by about 2 Research Octane numbers when the car radio was turned on and the windows closed. Both customers and raters reported more knock with 1975-1977 model cars than with earlier models. Since 1975, octane requirements of certain car models tended to be adjusted to the octane quality of available gasoline.

Bettoney, W. E., Rogers, J. D., Riegel, J. E.

Road Octane Number Trends of Japanese Passenger Cars

To develop empirical road octane number (RdON) equations and to obtain the relationship between high speed RdON and fuel quality, RdON were determined by the Modified Uniontown Technique (MUT) and the Modified Borderline Technique (MBL) using 1974 and 1975 Japanese passenger cars. The effects of RON and DON on RdON-MUT were more pronounced than that of MON. Aromatic and olefin hydrocarbon types had little influence on RdON-MUT. RdON-MBL measured at low speed was similar to RdON-MUT. As speed increased, however, it was influenced by MON. Road octane number depreciation (ΔRdON) at high speed was increased with sensitivity or olefin content.

Date, K., Nishizaki, T., Maeda, T.

Gasoline Consumption for the Car Fleet of Tomorrow

During the next eight years (to 1985), U.S. motor gasoline consumption is expected to increase slightly, level off, and then begin a slow decline. President Carter's proposed National Energy Plan may result in an even faster decline in gasoline sales if it is sanctioned by Congress. Over the same period, the required gasoline pool octane will increase in response to increased unleaded gasoline sales, the EPA's lead phase-down schedule and predicted engine modifications for improved efficiency. This paper reviews the effects of these trends on the refining industry. Gasoline shortages are not foreseen, assuming reasonable regulatory actions by government.

Ormiston, R. M., Pollock, G. G.

ESTABLISHMENT OF ORI CHARACTERISTICS AS A FUNCTION OF SELECTED FUELS AND ENGINE FAMILIES

Octane requirements of 55 cars, representing five Ford engine families, were determined every 2000 miles during a deposit accumulation schedule consisting of city, suburban and highway operations. Five cars from each engine family were operated on certification durability fuel to establish the ORI variation within and between families. Additional cars and fuels were used to investigate the effects of lead content, a detergent additive, and higher boiling fuel components on ORI. The data obtained show that among engine families there were characteristic differences in ORI and that the initial ORI build up occurred more rapidly when the investigated detergent additive was used. The fuel with reduced tail-end volatility was found to increase ORI. ORI with leaded versus unleaded fuels was found to be greater with unleaded fuels but with wide variation between the engine families studied.

Niles, H. T., McConnell, R. J., Roberts, M. A., Saillant, R.

Some Observations of Factors Affecting ORI

A review has been made of anomalies that exist in the changes in octane requirement of recent model cars operated for several thousand miles using unleaded gasolines and SE quality oils. A number of laboratory multicylinder engine tests have been conducted to elucidate possible reasons for some of these anomalies. These tests have uncovered mechanical variables that can produce relatively rapid changes in the octane requirement of an engine and octane requirement differences between engines of the same make and model, operated on identical combinations of gasoline and oil. Two of the more important variables are the initial octane requirement and the amount of oil migrating to individual cylinders in the engine.

Alquist, H.E., Holman, G.E., Wimmer, D.B.

Environmental Considerations and the Energy Crisis - the Effect on Gasoline Composition

The current shortage of gasoline and the existence of vehicle emission standards have raised the question of what tomorrow's gasoline will be like. This paper reviews the environmental considerations and the energy supply situation, discusses the likely future processing schemes, and considers the gasoline properties expected in the future. In general, we believe the current processes will continue to be used and future gasolines will have properties similar to present fuels. More octane numbers will be obtained by processing than by the use of lead alkyls, which may result in more aromatics and less sulfur.

Spindt, R. S., Kline, R. E.

ORI in 1971 Model Cars - With and Without Lead

During 1970-1971, 15 organizations participated in a Coordinating Research Council program to compare the influence of unleaded and leaded gasolines on octane requirement increase (ORI). A total of 147 1971 model cars (47 pairs and 53 individual cars) were operated for 8000-20,000 miles using driving schedules prescribed by each participant One car of each pair was run on an unleaded fuel of 91-95 Research octane number (RON) and the other on a leaded fuel of similar quality. For paired cars, the average ORI was 5.8 RON for unleaded and 3.8 RON for leaded fuel cars. The ORI difference of 2.0 RON for paired cars was slightly less than the average ORI difference of 2.5 RON for all 75 unleaded and 48 leaded cars. In a supplemental program, results in 20 cars showed an average ORI difference of only 0.3 RON between unleaded and low-lead fuel cars.

Bigley, H. A., Benson, J. D.

An Example of Experimental Design Methods

The application of experimental design methods to practical engineering problems is illustrated by an example involving road tests to measure how elevation affects octane requirements of automobiles. The example describes steps involved in developing an efficient statistical design that fits technical requirements of the problem, and describes analysis of data and interpretations of results.

Wagner, T.O., Gorman, J. W.

Engine-Fuel Relationships with L.P.G. and Natural Gas

Several parameters of engine-fuel relationships with leaded and unleaded LP-gas and natural gas are discussed. Performance factors include the effect of carbureted gaseous fuels on observed and corrected volumetric efficiency. Emphasis was placed on the knock-limited spark advance (KLSA) characteristics as a function of engine speed for all fuels tested at engine compression ratios of 9.1 and 10.6. Results showed that the knock-limited spark advance increased with decreasing engine speed with both LP-gas and natural gas fuels. The amount of change or increase appeared to be related to both fuel types and relative fuel octane quality as referenced to the engine requirement.

Kuivanen, Gordon J., Westra, Rolland O., Lien, Dallas G.

GASOLINE PROPERTIES AFFECTING FUEL ECONOMY

This paper discusses gasoline properties which affect fuel economy. It deals with (1) the available energy in the fuel as related to fuel composition and (2) the chemical and physical characteristics of the fuel as they affect the conversion of this energy into work. It shows that (1) the energy contents of commercial gasolines falls within a narrow range, (2) increasing octane number of the gasoline will not necessarily increase gasoline economy, (3) volatility is important to obtaining good mileage, and (4) gasoline must be kept free of contaminants.

Foringer, D. E.

The Effects of Cylinder Size On Detonation and Octane Requirement

Taylor, C. Fayette

New Tools for Understanding the Two Stroke Cycle Engine and Its Octane Number Requirements

Grant, Hendrie J., Newman, Neil A.

TETRAMETHYL LEAD REDUCES LOW SPEED KNOCK

This paper discusses recent data which give a comparison between the low speed road antiknock performance of fuels containing tetramethyl lead and that of fuels with tetraethyl lead. It is shown that the substitution of tetramethyl lead for tetraethyl lead in fuels having overhead (60-90% distilled) fractions of low octane quality (relative to the octane quality of the total fuel) results in a marked improvement in low speed road antiknock behavior. The difference in volatility between the two antiknocks is shown to influence the distribution of octane quality throughout the boiling range of the gasoline. The octane distribution, in turn, is characterized by a variable of the fuel called “Delta R” which has been found to predict the observed low speed advantage for tetramethyl lead. “Delta R” is defined as the Research O.N. of the fuel minus that of an appropriate overhead fraction. This advantage for tetramethyl lead is also predicted qualitatively based on the mechanism of “fuel

KORN, T. M., MOSS, G.

MARINE ENGINE OCTANE RATING PROGRAM

WELLS, R. A., BOEGEL, M. J., VOLLMER, J. C.

the economics of HIGH-OCTANE GASOLINES

FUEL of 97 + octane number gives the most miles for the dollar, present calculations show. At this point, increased efficiency from high compression ratios equals the rising cost of high-octane fuel. For town driving about 95 octane is inherently the least expensive, and over-the-road cars can benefit from gasolines up to almost 99 octane number. This paper describes an analysis made by California Research Corp. of the costs and the value of high-octane gasolines. The economics of octane numbers was based on current commercial practices regarding improved efficiencies of higher compression ratio cars and higher manufacturing costs of higher octane gasolines. The authors believe that if compression ratio and octane number stay in proper relation to each other, the consumer will benefit.

Kavanagh, F. W., MacGregor, J. R., Pohl, R. L, Lawler, M. B.

OCTANES FROM MOTOR OILS

Motor oils contribute to combustion-chamber deposits and therefore to octane-requirement increase (ORI) and surface ignition. An investigation of the separate components of motor oils in laboratory engines showed that base oils add the largest increment to ORI, viscosity-index improvers add less, and detergents and inhibitors add the least. Surface ignition is reduced by phosphorus, barium, calcium, and zinc ─ elements commonly found in motor-oil additives. Phosphorus is especially effective; all tested additives containing it were equally effective at the same concentration of phosphorus. The components chosen for a motor oil determine how much it will contribute to ORI and surface ignition. A good choice of base stock, viscosity-index improver, and detergent for an SAE 10W-30 oil gives an ORI 6 octane numbers lower than a poor choice. Similarly, choosing phosphorus-containing detergents and inhibitors reduces octanes needed to suppress surface ignition as much as l4 units. Good

KALINOWSKI, M. L., LA CROIX, L. D., NEJDL, R. A.

A Basis for Understanding Antiknock Action

THIS paper analyzes ignition-delay data and knocking characteristics of fuels. An approach to the problems of fuel sensitivity and engine severity has been made by attempting to relate the properties of the fuel-air mixture as shown from ignition-delay data and the temperatures and pressures reached by the compressed gases in an engine. The relation between octane numbers and ignition-delay characteristics of the fuels is examined. Antiknock properties of tel are investigated. It is shown that the amount of antiknock effectiveness is related to the amount of tel decomposed.

Rifkin, E. B., Walcutt, C.

CORRELATIONS BETWEEN ROAD OCTANES, LABORATORY OCTANES, AND HYDROCARBON TYPE

FUEL ANTIKNOCK PERFORMANCE IN HIGH-COMPRESSION ENGINES

The trend toward motor fuels of higher antiknock quality and increased use of aromatic components from catalytic reforming prompted an investigation of the effects of Research and Motor octane numbers and composition on antiknock behavior in high-compression engines. Olefinic and aromatic blends covering a wide octane spread were knock-rated in the laboratory by a procedure designed to eliminate the abnormal ignition timing encountered when fuels are rated on the road. Engine ratings approached or exceeded Research octane number as octane level increased, and decreased with increasing spread between Research and Motor octane numbers. Compression ratio had no effect on engine ratings, but combustion-chamber design apparently affected the performance of highly aromatic fuels. Ratings of all fuels decreased with increase in engine speed, but aromatic blends decreased much less than olefinic blends. Thus, information on composition as well as Research and Motor octane numbers is needed to

DOMKE, C. J., ESAU, N. D., GRAY, D. S., TALIAFERRO, H. R.

THE EFFECT OF SIMULATED SURFACE IGNITION ON ENGINE PERFORMANCE

It has long been recognized that ignition of the fuel-air charge in Otto cycle engines can be and sometimes is induced by sources other than the electric spark. These additional sources of ignition may be any hot surface to which the fuel-air mixture is exposed. However, since the sources of ignition, other than the spark, which prevail are quite often transient in nature and difficult to reproduce, a systematic study of their effects on the performance of engines actually operating in service is a difficult and time consuming task. This difficulty can be circumvented, however, by employing controlled additional sources of ignition such as extra spark plugs or artificial and controllable hot spots. This paper presents the results of a series of tests made to study the influence of a controlled second source of ignition on performance in a single cylinder CFR overhead valve engine. An independently timed second spark plug was used to simulate surface ignition. It was found that surface

SHORE, L. B., KUNC, J. F.

EFFECTS OF LUBRICATING OIL ON OCTANE REQUIREMENTS OF CARS IN CUSTOMER SERVICE

BENNETT, P. A., LANDIS, J. R.

RELATIVE IMPORTANCE OF KNOCK AND AUTOIGNITION IN DETERMINING OCTANE REQUIREMENTS OF PASSENGER CARS

BENNETT, P. A., LANDIS, J. R.

Possible Mechanisms by which Combustion-Chamber Deposits Accumulate and Influence Knock

THREE mechanisms by which combustion-chamber deposits might increase the octane requirement of an engine are discussed in this paper. These are volume, catalysis, thermal insulation. The experiments reported here indicate that the increase in compression ratio caused by deposit volume accounts, for 20-40% of the octane requirement increase, catalysis may not be a contributing factor, and the thermal insulating effect of the deposits is one of the major causes of deposit knocking harm.

Effects of Combustion-Chamber Deposits on Octane Requirement and Engine Power Output

CONTROLLED service tests were carried out to measure the effects of combustion-chamber deposits upon octane requirement and power output of passenger-car engines. Engine power loss attributable to deposits varies rather widely with engine design. The effect of combustion chamber deposits is probably no greater than that of other factors, such as changes in ignition system characteristics.

Duckworth, J.B.

EFFECT OF VARIATION IN PASSENGER CAR OCTANE REQUIREMENTS ON THE UTILIZATION OF MOTOR GASOLINE QUALITY

Grosser, W. R., Kelly, H. S.

ALCOHOL-WATER INJECTION FOR HIGH COMPRESSION ENGINES ¹

Porter, James C.

THE NEW CADILLAC ENGINE

TO illustrate a successful approach to the problem of designing a higher compression engine, the authors show here the course followed in the development of the new Cadillac engine. Although it appears the basic design of this engine can be used up to a compression ratio of 12-1, the authors say that the actual compression ratio of the future Cadillac engine will depend upon: 1. The production of higher octane fuel at a suitable price. 2. Technological progress by the petroleum industry. 3. The urgency of the need for conserving our natural resources. 4. How insistently the motorist demands more miles per dollar. 5. Plain, old-fashioned competition.

BARR, H. F., COLE, E. N.

KNOCK - LIMITED PERFORMANCE of Several Automobile Engines

REPORTED here is a program designed to give the knock-limited performance at full-throttle operation of 24 automobiles. Various models were used in the test work, including four 1942 models that were converted to higher than normal compression ratios to simulate a possible future trend. Curves have been developed to show how octane number correlates with the performance of these standard and special engines as they are installed in automobiles.

BARBER, EVERETT M.

Items per page:

1 – 50 of 73