High-Speed High-Output Diesel Engines - Revision history

Toro Andersen at 14:32, 4 October 2026

2026-10-04T14:32:33Z

Toro Andersen at 13:41, 4 October 2026

2026-10-04T13:41:33Z

Toro Andersen at 13:37, 4 October 2026

2026-10-04T13:37:39Z

@@ Line 56: / Line 56: @@
 "specific power per unit of piston area" (N/F)<math>\sqrt{s/d}</math>
@@ Line 195: / Line 196: @@
-the specific power-to-swept volume ratio is inversely pro-
+for a given load category and geometrically similar engines, the specific power-to-swept volume ratio is inversely pro-
 portional to the bore.
-Fig. 10 shows the relationship between the specific pow-
+Fig. 10 shows the relationship between the specific power-to-swept volume factor and the bore for different values of the specific power-to-piston area factor. For example, with geometrically similar engines of equal thermal and mechanical stressing of their piston resp, crankshaft assemblies, the doubling of the bore would halve the power per unit swept volume. In the same figure data are plotted for four high-speed engines belonging to four different performance categories, and one slow-speed marine propulsion engine.
 The data of these engines are listed in Table 2.
-Table 2 shows that a normal high-speed engine (for ex-
+Table 2 shows that a normal high-speed engine (for example, Engine No. 1) has the same power output per unit of piston area as the slow-speed marine engine No. 5, where the power of the latter must be regarded as being rather high compared with other similar engines. With high-speed engines, however, by means of suitable measures such as piston cooling the specific power output per unit of piston area can be increased for marine engines to 304 bhp/ft?, as shown for No. 3 engine. Yet this still does not exhaust the possibilities of increasing the specific power output. As No. 4 engine shows, by an increase in speed, mean effective pressure, and by other measures, the specific power-to-piston area factor of the same engine can be raised to beyond 600 bhp/ft?, a value which cannot be approached even remotely by slow-speed engines. This comparison clearly demonstrates the possibilities for high-speed engines to increase their specific power output; it also demonstrates the wide power range which can be obtained with one and the same engine.
 The higher the specific power-to-piston area factor is of an engine which has proved to be reliable in actual service, the higher is the standard of technical development which the particular engine can be said to have reached. Hereby the measures are quite decisive by means of which higher specific power output per unit piston area has been attained, without exerting a detrimental influence on the reliability of the engine.

Toro Andersen at 10:55, 4 October 2026

2026-10-04T10:55:50Z

← Older revision		Revision as of 10:55, 4 October 2026
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	"specific power per unit of piston area" (N/F)<math>\sqrt{s/d}</math>		"specific power per unit of piston area" (N/F)<math>\sqrt{s/d}</math>



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	To simulate the maximum stresses in the cylinder head and liner due to ignition pressure Pz, the tangential stress		To simulate the maximum stresses in the cylinder head and liner due to ignition pressure Pz, the tangential stress
			[[Category:Articles]]

Toro Andersen at 10:55, 4 October 2026

2026-10-04T10:55:29Z

Show changes

Toro Andersen at 08:18, 4 October 2026

2026-10-04T08:18:35Z

← Older revision		Revision as of 08:18, 4 October 2026
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	"specific power per unit of swept volume" (N/V)<math>\sqrt{s/d}</math>		"specific power per unit of swept volume" (N/V)<math>\sqrt{s/d}</math>

	"specific power per unit of piston area" (N/F)√s/d		"specific power per unit of piston area" (N/F)<math>\sqrt{s/d}</math>

Toro Andersen at 06:41, 4 October 2026

2026-10-04T06:41:45Z

← Older revision		Revision as of 06:41, 4 October 2026
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	The fact that the ratio of power per unit of swept volume is influenced by the stroke-to-bore ratio can be explained by the fact that as this ratio changes there is also a change in the ratio of the heat-affected surface to the corresponding swept volume. With the longer stroke engine, where the piston diameter is smaller, the distance of heat flow from the center of the piston crown to the cylinder wall is smaller. Therefore, the temperatures at the center of the piston crown become higher if the piston diameter is increased. The results of similar investigations on the influence of cylinder bore and stroke-to-bore ratio on the piston temperature are plotted in Fig. 7. This graph shows that, even if mean effective pressure, piston speed, and stroke-to-bore ratio remain constant, an increase in the cylinder bore causes higher temperatures at the center of the piston crown. It will also be noted that the increase is steeper with short-stroke engines than with long-stroke engines. In order to obtain more realistic parameters for comparisons, the ratios of power per unit of swept volume and power per unit of piston area must be related to the stroke-to-bore ratio √s/d as follows:		The fact that the ratio of power per unit of swept volume is influenced by the stroke-to-bore ratio can be explained by the fact that as this ratio changes there is also a change in the ratio of the heat-affected surface to the corresponding swept volume. With the longer stroke engine, where the piston diameter is smaller, the distance of heat flow from the center of the piston crown to the cylinder wall is smaller. Therefore, the temperatures at the center of the piston crown become higher if the piston diameter is increased. The results of similar investigations on the influence of cylinder bore and stroke-to-bore ratio on the piston temperature are plotted in Fig. 7. This graph shows that, even if mean effective pressure, piston speed, and stroke-to-bore ratio remain constant, an increase in the cylinder bore causes higher temperatures at the center of the piston crown. It will also be noted that the increase is steeper with short-stroke engines than with long-stroke engines. In order to obtain more realistic parameters for comparisons, the ratios of power per unit of swept volume and power per unit of piston area must be related to the stroke-to-bore ratio √s/d as follows:

	"specific power per unit of swept volume" (N/V)<math>\sqrt{s/d},</math>		"specific power per unit of swept volume" (N/V)<math>\sqrt{s/d}</math>

	"specific power per unit of piston area" (N/F)√s/d		"specific power per unit of piston area" (N/F)√s/d

Toro Andersen at 06:41, 4 October 2026

2026-10-04T06:41:13Z

← Older revision		Revision as of 06:41, 4 October 2026
Line 53:		Line 53:
	The fact that the ratio of power per unit of swept volume is influenced by the stroke-to-bore ratio can be explained by the fact that as this ratio changes there is also a change in the ratio of the heat-affected surface to the corresponding swept volume. With the longer stroke engine, where the piston diameter is smaller, the distance of heat flow from the center of the piston crown to the cylinder wall is smaller. Therefore, the temperatures at the center of the piston crown become higher if the piston diameter is increased. The results of similar investigations on the influence of cylinder bore and stroke-to-bore ratio on the piston temperature are plotted in Fig. 7. This graph shows that, even if mean effective pressure, piston speed, and stroke-to-bore ratio remain constant, an increase in the cylinder bore causes higher temperatures at the center of the piston crown. It will also be noted that the increase is steeper with short-stroke engines than with long-stroke engines. In order to obtain more realistic parameters for comparisons, the ratios of power per unit of swept volume and power per unit of piston area must be related to the stroke-to-bore ratio √s/d as follows:		The fact that the ratio of power per unit of swept volume is influenced by the stroke-to-bore ratio can be explained by the fact that as this ratio changes there is also a change in the ratio of the heat-affected surface to the corresponding swept volume. With the longer stroke engine, where the piston diameter is smaller, the distance of heat flow from the center of the piston crown to the cylinder wall is smaller. Therefore, the temperatures at the center of the piston crown become higher if the piston diameter is increased. The results of similar investigations on the influence of cylinder bore and stroke-to-bore ratio on the piston temperature are plotted in Fig. 7. This graph shows that, even if mean effective pressure, piston speed, and stroke-to-bore ratio remain constant, an increase in the cylinder bore causes higher temperatures at the center of the piston crown. It will also be noted that the increase is steeper with short-stroke engines than with long-stroke engines. In order to obtain more realistic parameters for comparisons, the ratios of power per unit of swept volume and power per unit of piston area must be related to the stroke-to-bore ratio √s/d as follows:

	"specific power per unit of swept volume" (N/V)√s/d		"specific power per unit of swept volume" (N/V)<math>\sqrt{s/d},</math>

	"specific power per unit of piston area" (N/F)√s/d		"specific power per unit of piston area" (N/F)√s/d

Toro Andersen at 06:37, 4 October 2026

2026-10-04T06:37:06Z

Show changes

Toro Andersen at 21:11, 3 October 2026

2026-10-03T21:11:17Z

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 == High-Speed High-Output Diesel Engines - 35 Years of Development of Railroad and Marine Applications ==
 By Markus von Kienlin and G. W. Maybach
@@ Line 23: / Line 24: @@
 tons were made of aluminum. Convenient mounting of running parts posed a special problem at the time for these pow-
-White metal bearings could not be used, and
+White metal bearings could not be used, and lead-bronze bearings were still in too early stages of development. Therefore, it was decided to provide both the crankshaft and big ends with roller bearings, the composition of material and thermal treatment for which were the subject of lengthy and painstaking development by the company.
-The best solution in this direction appeared to be the disc-
+In operation, these engines attained mileages between general overhauls of as much as 100,000 miles (about 2500 operating hours) and more, which prior to World War I was regarded as quite satisfactory. After termination of World War Il the situation was entirely different. Under the influence of the immense advance of the diesel locomotive in the United States and elsewhere, railway companies became increasingly interested in converting their heavy traction service to diesel operation.
-webbed crankshaft, which inherently has greatly improved
+If European manufacturers wanted to take part in this development, they had to counter the American diesel locomotive with its heavy and slow-running engine by a type of vehicle which would be available for a more universal application, offer more favorable weight conditions, and which in respect of output and service life would at least equal the heavy engines.
-vibration characteristics, and which also provides ideal con-
+For Maybach Motorenbau, as the representative of the European trend, the demand for long life of the engine and components became small-size engines had to be designed which would be capable of offering mileages between overhauls at least equal to those then attained in rail traction by the finest types of slow-speed engines. Beyond that, these engines were supposed not only to compete successfully in the field of diesel traction, but also to conquer new fields of application. Considering that for the aforementioned GO-type engines the roller bearings in the big end of the connecting rods were the limiting factor for the running performance, it was obvious that further development should aim at plain bearings for the big ends and a modernization of all running parts.
-ditions for the entire bearing problem.
+The best solution in this direction appeared to be the discwebbed crankshaft, which inherently has greatly improved vibration characteristics, and which also provides ideal conditions for the entire bearing problem.
 This was confirmed by the experience gained by May-