BS 6507:1984 download free.British Standard Method for Bench testing engines for agricuftural tractors and machines for net power.
O INTRODUCTION
BS 6507 is in conformity with clause 7. and subclauses 6.1.3. 6.2 and 6.3.1 to 6.3.11 of ISO 1585; it relates to tests on an engine capable of being fitted into several types of agricultural tractors and machines.
1 SCOPE AND FIELD OF APPLICATION
BS 6507 specifies a bench method for testing the following categories of engines which are intended for use in agricultural tractors and machines and which may be fitted with a supercharging device using a mechanical supercharger or turbocharger
a) spark ignition engines;
b) compression ignition (diesel) engines;
Engines given in a) and b) can have the following variants
c) reciprocating internal combustion engines;
d) rotary piston internal combustion engines.
In particular, it allows curves to be plotted of net power and specific fuel consumption at full load as functions of engine speed.
2 REFERENCES
ISO 789/I. Agricultural tractors — Test pmcedures — Part I:
Power tests. 1)
ISO 1585, Road vehicles — Engine test code — Net power.
3 DEFINITIONS
For the purpose of BS 6507 the following definitions apply
3.1 net power: The power obtained on a test bed at the crankshaft or its equivalent, at the engine speed specified
5.3.4 No data shall be taken until torque, speed and temperature have been maintained substantially constant for at least 1 mm.
5.3.5 The engine speed during a run or reading shall not deviate from the selected speed by more than ± O or ± 10 revimin, whichever is the greater.
5.3.6 Observed brake load, fuel consumption and Inlet air temperature data shall be recorded simultaneously and shall in each case be the average of two stabilized sustained values which do not vary more than 2 % for brake load and fuel consumption.
5.3.7 A time of measurement of not less than 30 s shall be used when measuring speed and fuel consumption with an automatically synchronized counter timer combination; for hand operation, the time of measurement shall be not less than 60 s.
5.3.8 The coolant outlet temperature in liquid-cooled engines shall be controlled at 80 ± 5 °C unless otherwise specified by the manufacturei.
For air-cooled engines, the temperature at a point indicated by the manufacturer shall be kept within — of the maximum value specified by the manufacturer.
5.3.9 The fuel temperature at the inlet of the injection pump or carburettor shall be maintained within the limits established by the engine manufacturer.
5.3.10 The temperature of the lubricating oil measured in the oil sump or at the outlet from the oil cooler, if fitted. shall be maintained within the limits established by the engine manufacturer.
5.3.11 The exhaust temperature shall be measured at a point in the exhaust pipe(s) adjacent to the outlet flange(s) of the exhaust manifold(s). This temperature shall be maintained within the limits established by the engine manufacturer.
5.3.12 The fuel used shall conform to the specifications published by the manufacturer of the engine under test.
For diesel engines, the fuel shall be one supplied and delivered by the refinery to the customer without any supplementary smoke suppressant additives. In cases of dispute, tests shal be made with the CEC reference fuel CEC RF-03T-69. For spark ignition engines, in cases of dispute, tests shall be carried out using CEC reference fuel CEC RF-O1T-69 (see annexes A and B).
5.4 Test procedure
Record data at a sufficient number of operating speeds to define completely the power curve between the lowest and the highest engine speeds recommended by the manufactUrer. For part load performance measurement, see
ISO 789/l.
if these limits are exceeded, the corrected value obtained shall be given, and the test conditions (temperature and pressure) precisely stated in the test report.
NOTE — The tests may be carried out in air-conditioned test roon where atmospheric conditions may be controlled.
6.4 DetermInation of correction factors
6.4.1 Spark Ignition engines — Correction factor, a12). 3) The correction factor, a5. for spark ignition engines (carburettor or injection) shall be as calculated from the
T is the absolute temperature, in kelvins, at the air inlet to the engine;
p is the total dry atmosphere pressure, in kilopascals, i.e. the total barometric pressure minus the water vapour pressure.
6.4.2 Diesel engines (compression-ignition)
6.4.2.1 Correction factor, ad
The correction factor, ad, for diesel engines at constant fuel rate shall be as calculated from the formula
f is the atmospheric factor (see 6.4.2.2.);
fm is the engine factor, i.e. the characteristic parameter for each type of engine and adjustment (see 6.4.2.3).
6.4.2.2 Atmospheric factor
The atmospheric factor, f, which indicates the effect of environrnental conditions (pressure, temperature and humidity) on the air drawn in by the engine shall be as calculated from the foNowing formula:
a) normally aspirated and mechanically supercharged engines:
in which
q 18 the fuel flow, in milligrams per litre per cycle of engine swept volume per cycle Img/(l.cycie)I;
r is the ratio of the comprpsa outlet pressure to tr compressor inlet pressure ir 1 for normally aspwatecl engines).
The formula for the engine factor. f is only valid for a q value between 40 and 65 mg/fl.cycle). For values less than 40 mgi(l.cycle). a value of 0,3 shall be taken for/rn, whilst foi values greater than 65 mg/flcycle), a value of 1,2 shall oe taken fOtfm.
7 MEASUREMENT OF SMOKE VALUE
The measurement of smoke value is not currently included in the test code.
The measurement is optional.