Engine construction is exactly the same ie. pistons, rings, valves, injectors etc. the only difference is the fuel intake, so what exactly creates the louder mechanical noise.
2007-09-18 23:28:13 · 10 answers · asked by Tango 7 in Cars & Transportation ➔ Maintenance & Repairs
The basic engine construction may be the same (although most of the components actually differ - block, pistons, injectors), but the thermodynamic cycle in which the engine operates is different - the petrol engine operates on the Otto cycle, the diesel engine operates on the Diesel cycle.
In a petrol (Otto) engine the fuel/air mixture is ignited by a spark, and a flame front spreads through the cylinder, burning the fuel gradually and slowly in comparison to a diesel engine, giving a gradual increase in cylinder pressure.
In a diesel engine the fuel is injected into the cylinder after compression of the air in the cylinder, and is ignited instantly by the heat due to compression. This gives a more instant burn, and hence a faster increase in cylinder pressure. It is this more sudden increase in pressure that causes the characteristic diesel noise.
2007-09-19 06:11:48 · answer #1 · answered by Neil 7 · 1⤊ 0⤋
Noisy Diesel Engine
2016-12-12 15:16:03 · answer #2 · answered by egbe 4 · 0⤊ 0⤋
High noise levels in diesel engines (known as the diesel knock or clatter) that occurs, more pronounced when the engine is cold (just started) and at low rpm, is caused by the sudden ignition of the diesel fuel when injected into the combustion chamber. This noise is a product of the sudden temperature change (due to high compression 1:15 to 1:20 leading to high pressure resulting in high temperature), hence it was more pronounced at low engine temperatures.
2007-09-19 00:25:56 · answer #3 · answered by Viswajith K Navin 2 · 2⤊ 0⤋
Hi the noise created is by the diesel igniting as diesel ignites under compression and does not need a spark it just has to be warm.
Also diesel engines have a far greater compression ratio.
2007-09-19 02:37:17 · answer #4 · answered by maclaren 4 · 1⤊ 0⤋
Higher compression. Diesel explodes under pressure. Petrol burns when a spark ignites it. The noise is caused by the sudden temperature and pressure change, even more so when the engine is cold.
2007-09-18 23:33:15 · answer #5 · answered by ? 7 · 5⤊ 0⤋
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RE:
Why do diesel engines sound more noisy than petrol engines?
Engine construction is exactly the same ie. pistons, rings, valves, injectors etc. the only difference is the fuel intake, so what exactly creates the louder mechanical noise.
2015-08-06 17:40:36 · answer #6 · answered by Anonymous · 0⤊ 0⤋
High compression, Diesel engines fire on pressure, not spark.
2007-09-18 23:36:07 · answer #7 · answered by Anonymous · 1⤊ 0⤋
It has to do with the fact that diesel ignites at a higher temperature than petrol.
2007-09-18 23:40:40 · answer #8 · answered by Anonymous · 0⤊ 2⤋
due to heat of compression (high pressure)..
2014-02-21 06:16:55 · answer #9 · answered by none 1 · 0⤊ 0⤋
much higher compression rates, this is also why they are more economical.
2007-09-19 01:04:54 · answer #10 · answered by matrix 3 · 0⤊ 0⤋