Chainsaw Repair

Quote from: 1manband on March 06, 2016, 07:29:55 pm

......very tough to convince you of anything........hahahahaha.

LOL, I'm a bonehead for sure!   

But look at the red curve of Figure5 again.  This is at 3000rpm, or if scaled to an engine with a 10,000rpm power peak, it would be at 8,333rpm.  The red curve does not peak and fall off, it plateaus.  This is because once the case volume gets low enough the pressure differential gets very large, and you can no longer get ahead of the flow rate. 

glad you are having fun with it.

if you are on board with graph #5, being similar to #6......?  x-axis scale on #6, has a big 3000 to 6000 jump.

motor A's hp peak is at 3600 in stock form.  thinking it may only rev a few grand or so higher?

the only way to get an better handle on that would be to plug in it's numbers, which i have not done.  will have to look into that.  would be a good check.

i have not been focusing on pressure and mass flow, with this so much.  when the math came to a dead end, lost interest.  will rekindle that angle again eventually.  the fuel's mass compared to the air's is much greater.  kind of like wind trying to blow sand around on the beach.  takes a lot to get it moving because of the mass difference.  as rpm's rise, velocity naturally increases, looking just at pressure differentials may be bit deceiving because it is compressible flow.  lots of things going on.