Camshaft tuning is an essential a part of supercharger tuning. Camshafts orchestrate the valve opening and closing events in the engine and choose whether what comes out of our motor is beautiful high power music, or a mess of dysphonics. Using the appropriate supercharger optimized cam shaft can go a long way towards Supercharger Porting and provide considerable power gains for the investment invested.
To comprehend camshaft timing and camshaft selection we must understand first:
Relativity: Changing if the valves open or close (intake or exhaust) changes the the valve timing with respect to:
The piston position within the cylinder. Based on where the pistons is within the stroke, and where our company is inside the combustion cycle, then opening the valves will exploit the stress difference between the cylinder and also the intake and exhaust manifolds.As an example it might seem sensible that the ideal time and energy to open the intake valve is when there is peak vacuum inside the cylinder so that once the valve opens, the highest amount of clean air may be ingested. Similarly, it makes sense not to open the exhaust valve until peak cylinder pressures happen to be achieved in the combustion chamber and also the combustion is complete and all sorts of the ability is extracted.
The high and low pressure pulses developed by the design and runner lengths in the intake and exhaust manifolds.It would make sense to open up the intake valve just like the reflected pressure waves in the intake manifold get to the intake valve being a high-pressure area of the wave, thus opening the valve around this high-pressure point gives a ‘ram air’ effect through volumetric efficiency resonance tuning increasing air ingestion which increases power.Similarly on the exhaust side, it seems sensible to start the exhaust valve, just like the reflected low pressure (vacuum) portion of the exhaust wave (reflected back from the collector) reaches the back of the exhaust valve.
At this point soon enough there is both peak pressure inside the cylinder, and vacuum inside the exhaust which creates a higher pressure differential and a faster evacuating exhaust gas. With regards to the ignition timing event, for instance a shorter duration or advanced exhaust cam, opens the exhaust valve sooner with regards to when the mixture was originally ignited, because of this although by advancing the exhaust cam we may have matched our header design and opened the valve with the lowest possible exhaust back pressure for optimum efficiency, concurrently, we have now reduced the amount of time the mixture is combusted and perhaps opened the valve before reaching our peak cylinder pressures and disposed of some horsepower.
The intake valves with respect to the exhaust valves: and this is usually described with regards to lobe separation angles (the offset in degrees between the middle of the exhaust cam and between the core of the intake cam), or with regards to how many degrees of overlap (the number of degrees that both intake and exhaust valves are open at the same time).
Because the combustion in the cylinder occurs in a higher pressure than atmospheric pressure, and also, since exhaust valves are generally small compared to intake valves (for this same high-pressure reason) then exhaust gas velocity is much higher than intake gas velocity. So, in a few engines it really is helpful to open the intake valve sooner than usual during the last part of the exhaust stroke, this is known as overlap.
During overlap – in the very end from the exhaust stroke – the quantity of pressure left inside the cylinder is low so it will be possible to breathe in new air under atmospheric pressure, simultaneously, the high velocity of the exhaust gasses exiting help attract even more clean air from the intake side inside an effect similar to ‘syphoning’ in which the fluid (in our case air) flows as a continuous stream drawing in new intake air right after the old exhaust gas leaves.
The other part of phenomenon that concerns timing intake valves with regards to exhaust valves will be the duration of time where both valves are absolutely closed, which can be your power stroke. This is actually the area of the combustion cycle where the mixture may be compressed and combusted. If either (or both) intake or exhaust valves are open you will struggle to ebrtxr compress nor combust the mix, and also the absolute duration of time (in levels of rotation) that your mixture is combusted and able to reach peak cylinder pressures is afflicted with camshaft selection and cam timing. Something to remember is the fact that valve angle offers quite a bit related to exhaust scavenging, obviously you will definitely get maximum scavanging when the exhaust and intake valves had ‘line of sight’ i.e. in the event the valves were separated by an angle of 180*.
If you have, the exhaust air can directly pull in new air. Conversely, you would probably hold the least possible scavenging if you had valves that have been with a narrow angle (zero degrees in the extreme) in between each other, so that the air would essentially have to make a U turn to can be found in through the intake and get pulled out your exhaust.