jseng1 wrote:Slick - I started out with the timed Atlas breather. I got rid of it and use the reed valve. The timed breather does not work the same for all RPM when under load but the reed does. The air has to pulsate and it compresses. When the RPM changes - those pulsations do not always match the timed opening of the disc. We learned this in racing and discarded the timed discs. The reed doesn't care about timing - it just senses the pulsation. The four 1/8" holes in the cam are enough because once the positive air is pumped out there isn't much pulsating air movement going on. There are others who have tested and compared the reed to the timed breather - maybe they could chime in here.
I can accept your explanation of the phase difference between the timed disc and the actual pressure pulse.
The point I was trying to make in my previous post, is with the timed disc in place
, the reed does not improve the negative pressure in the sump, according to my measurements. I can only defer to your experience with the timed disc removed
It would be interesting if you can provide some pressure measurements with your new reed valve on your Atlas' timed port (you once posted your rotary disc is removed). If such data shows a substantial benefit, it is a pity a complete tear down is necessary to remove the rotary disc.