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What is delay period in CI engine?

Abstract. The ignition delay in a diesel engine is defined as the time interval between the start of injection and the start of combustion. This delay period consists of (a) physical delay, wherein atomisation, vaporization and mixing of air fuel occur and (b) of chemical delay attributed to pre-combustion reactions.

What are the factors affecting the delay period?

I C ENGINES – II Air Motion & Combustion •Factors Affecting the Delay Period : – Quality of fuel Self ignition temperature is the most important property of fuel which affects the delay period. A lower self-ignition temperature results in lower delay period. – Fuels with higher cetane number give lower delay.

What is the main objective of supercharging engine?

The objective of supercharging is to increase the charge density of the working medium (air or air-fuel mixture), by any means and with the help of a suitable system, before it enters the work cylinder, i.e., to precompress the charge.

What are the factors affecting knocking?

Factors Affecting Knock These are the temperature, pressure, density of the unburned charge and the time factors. Temperature factor includes inlet temperature of the mixture and temperature of the combustion chamber walls.

Which one affects knock Examveda?

Solution(By Examveda Team) The knock in diesel engine occurs due to Instantaneous and rapid burning of the first part of the charge. Diesel engine knocks when there is accumulation of fuel in the combustion chamber which happens when the injected fuel fails to burn as there will a huge delay period.

What is knocking in fuel?

Knocking, in an internal-combustion engine, sharp sounds caused by premature combustion of part of the compressed air-fuel mixture in the cylinder. These pressure waves force parts of the engine to vibrate, which produces an audible knock.

What are the key factors to reduce knocking in SI engine?

Because pressure and temperature are strongly linked, knock can also be attenuated by controlling peak combustion chamber temperatures by compression ratio reduction, exhaust gas recirculation, appropriate calibration of the engine’s ignition timing schedule, and careful design of the engine’s combustion chambers and …

What can I put in my engine to stop knocking?

Below are the top oil additives to stop car engine knocking, especially for older engines.

  • 1) Sea Foam SF16.
  • 2) Archoil AR9100.
  • 3) Liqui Moly Cera Tec Friction Modifier.
  • 4) Lucas Heavy Duty Oil Stabilizer.
  • 5) Red Line Break-In Oil.
  • 6) BG MOA Oil Supplement.
  • 7) Rev X Fix Oil Treatment.
  • 8) Lucas Engine Oil Stop Leak.

Why is my engine knocking when I accelerate?

Engine Knock. If you detect a rapid pinging, tapping sound coming from the engine as you drive, your engine could be suffering from knock. You may find this problem gets worse as you accelerate. Engine knock can also be caused by incorrect ignition timing, an incorrect air/fuel ratio or a malfunctioning knock sensor.

Will thicker oil stop engine knocking?

Once an engine starts to knock, the rod can fracture without warning. So, the first job in slowing down the deterioration is to thicken your oil viscosity and boost the oil pressure inside the engine. You’ll know if it is working because it should quiet the knocking.

What kind of noise does a bad oil pump make?

A noisy oil pump is a rare symptom, as oil pumps only make noise when they’re starting to fail. You’ll probably hear a whirring or whining sound when this happens, even when the car is idle. This indicates the oil pump’s internal gears are worn out, meaning you’ll need to replace the entire pump.

Can thin oil cause knocking?

The most common cause of all of these knocking problems is loss of oil pressure from a clogged filter and oil pickup screen causing oil pump failure or just running the engine low on oil from oil loss through oil burning, oil leaks, and lack of maintenance oil and filter changes.

Can you drive with a rod knock?

yes, you can do it. put some heavyweight gear oil in the crankcase, if one cylinder is knocking, pull the plug on it to diminish the pressure on the rod and lessen the knock, shift at 1500 rpm, keep your revs low, drive slow, coast as much as possible.

How much does it cost to fix a knocking rod?

On average, the cost to repair an engine rod can range anywhere from $2,500 or more depending on the vehicle. Potentially you could spend more than what the car is worth.

How long can you drive rod knock?

Not long at all. Rod knocks are often considered to be the death rattle. The last one I heard lasted about 200 miles or so. A rod knock is the bearings worn out and the rod slapping around on the crank.

Does rod knock go away at higher rpm?

It goes away in higher speeds when it gets louder.