Camshaft tuning is a vital a part of supercharger tuning. Camshafts orchestrate the valve opening and closing events in the engine and determine whether what comes out of our motor is beautiful high power music, or perhaps a mess of dysphonics. The usage of the correct supercharger optimized cam shaft can go a long way towards Supercharger Rebuilding and give considerable power gains for the money 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 regarding:
The piston position within the cylinder. According to in which the pistons is in the stroke, and where we have been within the combustion cycle, then opening the valves will exploit pressure distinction between the cylinder and the intake and exhaust manifolds.As an example it could make sense that the ideal time for you to open the intake valve is when there is peak vacuum inside the cylinder in order that if the valve opens, the highest level of outdoors could be ingested. Similarly, it makes sense to not open the exhaust valve until peak cylinder pressures happen to be achieved within the combustion chamber as well as the combustion is finished and all of the power is extracted.
The high and low pressure pulses created by the design and runner lengths in the intake and exhaust manifolds.It would sound right to open up the intake valve just like the reflected pressure waves inside 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 offers 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) part of the exhaust wave (reflected back through the collector) reaches the rear of the exhaust valve.
At this stage in time there is both peak pressure in the cylinder, and vacuum within the exhaust which results in a higher pressure differential along with a faster evacuating exhaust gas. With respect to the ignition timing event, for example a shorter duration or advanced exhaust cam, opens the exhaust valve sooner regarding when the mixture was originally ignited, this means that although by advancing the exhaust cam we could have matched our header design and opened the valve with the lowest possible exhaust back pressure for best efficiency, at the same time, we have now reduced how much time that this mixture is combusted and perhaps opened the valve before reaching our peak cylinder pressures and disposed of some horsepower.
The intake valves with regards to the exhaust valves: and this is usually described when it comes to lobe separation angles (the offset in degrees between the middle of the exhaust cam and between the core of the intake cam), or when it comes to how many degrees of overlap (the number of degrees that both intake and exhaust valves are open concurrently).
Since the combustion inside the cylinder occurs with a much higher pressure than atmospheric pressure, and also, since exhaust valves are generally small compared to intake valves (with this same high-pressure reason) then exhaust gas velocity is much more than intake gas velocity. So, in a few engines it is actually good for open the intake valve sooner than usual during the last portion of the exhaust stroke, this is known as overlap.
During overlap – at the very end of the exhaust stroke – the quantity of pressure left inside the cylinder is low therefore it is possible to breathe in new air under atmospheric pressure, simultaneously, the top velocity from the exhaust gasses exiting help attract much more clean air through the intake side inside an effect just like ‘syphoning’ where fluid (in our case air) flows as a continuous stream drawing in new intake air following the old exhaust gas leaves.
One other element of phenomenon that pertains to timing intake valves with regards to exhaust valves is definitely the period of time where both valves are absolutely closed, that is your power stroke. This is actually the portion of the combustion cycle where the mixture can be compressed and combusted. If either (or both) intake or exhaust valves are open you may be unable to ebrtxr compress nor combust the mix, and also the absolute period of time (in degrees of rotation) that your mixture is combusted and allowed to reach peak cylinder pressures is impacted by camshaft selection and cam timing. One important thing to notice is that the valve angle has a lot concerning 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 so, the exhaust air can directly pull in new air. Conversely, you would probably have the least possible scavenging if you had valves which were with a narrow angle (zero degrees on the extreme) between each other, so the air would essentially have to make a U choose come in with the intake and acquire pulled out the exhaust.