In an internal combustion engine, there is the combustion chamber, a piston and an inlet and an outlet. These outlet and inlets are actually valves that act as doorways to let in the combustion mixture and take out the exhaust gases. But what we do not know is that these valves actually serve a bigger function than just that and that is maintaining the pressure levels inside the chamber and sealing it away from the outside world. The valves are proper doorways and seals to make sure that the compression are done in a proper manner and there are no leakages from any ends.Now one has to understand that the burned valve does cause issue, but it is not a problem, but it is an effect of an already existing problem which needs addressing. So if you happen to have a burnt valve in the engine then you really need to look out for the following issues with your bike as follows:
1. Engine Overheating:
During the combustion cycle of the engine, the valves open and close continuously at tremendous speeds. Now in this the exhaust valves are the ones under more stress because they are the ones to let off the hot air after combustion and for this process they do heat up. This is the reason why they are provided with properly conduction at the valve head so that the heat dissipation is done at a proper rate. But if the engine happens to overheat and the heat dissipation is not possible in a proper manner, then in that case the Valve of the engine burns.
2. Engine Running Lean:
When the engine is running lean, there is more air than fuel in the mixture and a lot of this air is unused in the process. This air is then hot and since is unburnt, carries a lot of heat with it which eventually ends up heating the valves a lot causing them to burn. Also the unused air can even cause corrosion to the inside of the engine including the valves overtime.
3. Incorrect Seal Fitting:
The seals fitted at the zero stage of the valves have to be proper. If they are not the valve would not fit properly and there will be leakage in the system. This leakage will carry on during the combustion process and the heat and flames will all escape out at an untimely manner and this will result in the burning of the valve.
4. Carbon Deposits:
If the fuel quality sometimes is not proper, then in that case the fuel when burnt creates a lot of carbon dust which settles inside the combustion chamber and hence causes carbon deposit issues. These deposits causes problems later on of valves not being shut properly and creating leakages in the engine, etc. which later leads to valves being burnt due to loss of compression.
5. Valve Spring Malfunction:
The valves movement is all taken care of the springs which aid in the opening and closing of the valves. So in case the springs of the valves goes kaput, then the valve does not open and close properly leading to jamming of the valves and this later goes on to cause troubles. This is why the valve stays open or closed unevenly and causes issues with the heat transfer and in combustion leading to burnt valves.
During the combustion cycle of the engine, the valves open and close continuously at tremendous speeds. Now in this the exhaust valves are the ones under more stress because they are the ones to let off the hot air after combustion and for this process they do heat up. This is the reason why they are provided with properly conduction at the valve head so that the heat dissipation is done at a proper rate. But if the engine happens to overheat and the heat dissipation is not possible in a proper manner, then in that case the Valve of the engine burns.
2. Engine Running Lean:
When the engine is running lean, there is more air than fuel in the mixture and a lot of this air is unused in the process. This air is then hot and since is unburnt, carries a lot of heat with it which eventually ends up heating the valves a lot causing them to burn. Also the unused air can even cause corrosion to the inside of the engine including the valves overtime.
3. Incorrect Seal Fitting:
The seals fitted at the zero stage of the valves have to be proper. If they are not the valve would not fit properly and there will be leakage in the system. This leakage will carry on during the combustion process and the heat and flames will all escape out at an untimely manner and this will result in the burning of the valve.
4. Carbon Deposits:
If the fuel quality sometimes is not proper, then in that case the fuel when burnt creates a lot of carbon dust which settles inside the combustion chamber and hence causes carbon deposit issues. These deposits causes problems later on of valves not being shut properly and creating leakages in the engine, etc. which later leads to valves being burnt due to loss of compression.
5. Valve Spring Malfunction:
The valves movement is all taken care of the springs which aid in the opening and closing of the valves. So in case the springs of the valves goes kaput, then the valve does not open and close properly leading to jamming of the valves and this later goes on to cause troubles. This is why the valve stays open or closed unevenly and causes issues with the heat transfer and in combustion leading to burnt valves.
So now that we know the reasons how valves could burn or do burn, it is also important to know what happens when the valves burn and the solution for it. When valves burn, they develop cracks in them and this leads to first and foremost, loss in the compression of the engine. This affects the performance of the engine big time and leads to even misfiring or uneven combustion that can leads to sputtering of the engine or even stalling of the engine mid-cycle and so on.The solution actually means simply changing the broken valve but also along with that, one has to check that this issue need not appear once again and hence tweaking the bike is important. The spring, the seals, the carbon deposition, the fuel mixture, etc. everything needs to be properly checked out else the issue will keep of persisting.
So this is the issues with a burnt valve. One should address it ASAP or else it could lead to permanent engine damage and when that happens, we all know the issues one has to face which means having to fit in a completely new engine to the engine catching fire or blasting which can be fatal as well. So make sure your engine is in perfect shape and running well and keep it maintained and proper at all times.
By: Pratik Patole