Mechanical Engineering - IC Engines and Nuclear Power Plants - Discussion
Discussion Forum : IC Engines and Nuclear Power Plants - Section 1 (Q.No. 7)
7.
The exhaust valve in a four stroke cycle petrol engine
Discussion:
17 comments Page 1 of 2.
Ashish said:
1 decade ago
Exhaust valve opens before 50 degree of BDC and remains open even after completion of exhaust stroke after 20 degree TDC so that it ensures complete removal of flue gaseous from cylinder.
Hence it avoids deterioration of fresh incoming charge during suction stroke which may mix with these burnt gaseous. This time lag of opening and closing of valve is essential during high speed as less time is available for flue gaseous to be thrown away.
Hence it avoids deterioration of fresh incoming charge during suction stroke which may mix with these burnt gaseous. This time lag of opening and closing of valve is essential during high speed as less time is available for flue gaseous to be thrown away.
RAJA MUTHU KUMAR said:
4 years ago
The effect of opening the exhaust valve before the piston reaches the BDC results in an overall gain in output. The effect of closing the exhaust valve after TDC is the inertia of the exhaust gases tends to scavenge the cylinder by carrying the maximum amount of gas left in the clearance volume. This will result in increased volumetric efficiency.
(1)
Narayan said:
9 years ago
The exhaust valve is kept open for such prolonged duration in order to let the products of combustion escape from combustion cylinder. This setting is different for light and heavy engines and may also differs with different automakers.
J bhargavi baaji said:
1 decade ago
Here the angle doesn't matters. As per the value timing diagram, value open before the the cycle starts and closes after the cycle. As per the question, the value opens before the exhaust process ie before the BDC and closes after TDC.
Md.RafiqueAzad said:
8 years ago
Cam profile is 60 degree so if it begins to open 50deg before BDC; it should travel not more than 120deg. i.e exhaust valve should close at 110 deg before TDC.
Mohammad Safiq said:
6 years ago
In the Valve timing diagram of the four-stroke engine the last stroke is the exhaust so for the modified valve timing diagram the Valve opens before BDC.
Sangangouda patil said:
1 decade ago
In valve timing diagram it is a 4 stroke called exhaust stroke hence exhaust valve opens before BDC at 50 and closes after TDC 15.
Vicky said:
9 years ago
How the opening and closing of an imelt valve and exhaust valve depend on the angle? Give reason with proof.
SIT said:
1 decade ago
Valve timing diagram: opening of valves are before and after dead centers.
Viswa said:
1 decade ago
In valve timing diagram any valve open always before either bdc or tdc.
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