In terms of reliability yes, however I was thinking in terms reducing friction... wouldn't every hp they could squeeze out be helpful. The snowball effect of which has been discussed here. My (admittedly non-enigneer) brain would think the close to 5 bar boost would require some heavy duty springs?
I dont see how friction to turn the cam would change much versus pneumatic if the springs are designed properly. Pneumatic is also addtional complexity and space taken up.ncassi22 wrote: ↑Sat Jan 13, 2018 1:39 amIn terms of reliability yes, however I was thinking in terms reducing friction... wouldn't every hp they could squeeze out be helpful. The snowball effect of which has been discussed here. My (admittedly non-enigneer) brain would think the close to 5 bar boost would require some heavy duty springs?
I didn't take into account that the air would need to apply the same pressure as a physical spring would to keep the valve closed or pressed against the rocker. Pretty dumb on my part
I have not denied their existence - my point is that as soon as you need more than 1 spring and friction damping you are already better off using a pneumatic system.bill shoe wrote: ↑Fri Jan 12, 2018 10:28 pmGoogle "triple valve springs", then go to images. It's the standard high performance valvespring config. I think the middle spring is often there to provide control and light damping to the inner and outer springs that do most of the heavy lifting.
I know, right? I've wondered that from the start and the only thing that seems possible is for the injector to create a denser cloud close to the holes in the pre-chamber and then hope that enough of it gets sucked/ pushed in there by the compression. (The pressure gradient is evened out/ lowered so that it is equal on both sides of the "membrane" that the holes form, thereby pulling the fuel with it.)amho wrote: ↑Fri Jan 12, 2018 8:23 pmI always thought that the injector is placed in the top of prechamber, but If injector is in exhaust side (as motor fan pic. indicates) how do they have rich mixture in the prechamber? there might be multiple injection first one when piston is near tdc to mainly fill prechamber?hurril wrote: ↑Fri Jan 12, 2018 8:15 am
Injectors on the exhaust side is nothing strange. The injector merely sits on the cylinderbank together with the exhaust valves instead of with the intake valves.
https://drive.google.com/open?id=1tpCUl ... SY3ZJV5gNa
For my simple view Hysteresis is when the rebound properties of the spring are different from the bound properites.. Making the spring slighlty unseat at high cycle speed..Tommy Cookers wrote: ↑Sat Jan 13, 2018 11:46 am'prevent hysteresis' - what nonsense ?!
hysteresis is an inherent characteristic of the material and not something that can be changed by design
metals have little hysteresis and higher strength versions of metals ie spring materials have less than little hysteresis
so the best qualified spring materials via high strength are also the best via low hysteresis
hysteresis can down in the region of ten parts per million and should be close to that in a performance valve spring
ok a race valve spring will be generating thousands of times per second that hysteresis (loss of strain energy) as self-heat
which will certainly need removing by properly designed coolant flow
force measurement in eg wind tunnel tests of race cars or when buying a piece of steak depends on the low hysteresis of metal
the load cells or balances work by measuring the dimensional change in metal with change in load
hysteresis would show as a residual error ie the output not returning to zero when the load is removed
true hysteresis is the residue after unloading and allowing the self-heat to disperse
most load cells are fortunately small enough for natural heat dispersion within the time taken by the calibration procedure
but with large load cells the calibration procedure should allow for this (but probably hasn't)
various behaviours of the strain-sensing side tend to add to an overall measurement 'hysteresis'
regarding eg triple valve springs (or similar doubles) ..... afaik
interference friction develops at incipient surge resonance of main spring(s) and by design this won't be at continuous rpm
Compression Spring Hysteresis:
The mechanical energy loss that occurs as a result of the spring ends' tendency to rotate when compressed during cyclic loading and unloading.