Yes, with respect the increase in tap size will not effect static head pressure at the float needle valve, only the available flow.
The two main factors in head pressure calculus are height and Specific Gravity(density) of the fluid in play.
In a vented tank situation the available flow is irrelevant,
unless there is a lack of it>then starvation>lean burn on wide open throttle straights and other high demands, dune riding etc.
Back to our all eyes mystery
In regards to
Head or rather verticle head is a measure of the height of liquid above a set point. No matter how wide it is the actual pressure will be the same at a given depth.(ocean or bucket its the same) With that said, friction in a smaller pipe increases thus slowing flow but in the size we are discussing this is negligible and not worthy of calculating.
There are a few miniscule variances not worth calculating eg; Temperature for one,
BUT, one very important factor of calculation is the density(specific gravity) of the liquid in mention.
Pure unadulterated H2O weighs the "basis of the entire metric system" ie; 1 Kilogram per liter.
The old super grade came in at close to .75 kg per liter(fuel floats on water because its lighter gig).
0.8 of a kilogram per liter is a very close mean for all intents and purposes for our fuel/oil two smoker blends,,,,
So the head pressure outcome at the float needle valve seat is actually 20% less if considering mixed fuel/oil of a 2T than if it were a calculation factored from say the SG of water instead.
If considering the pressure at the float needle seat of my 78 Magnum (from calculation, not pressure gauge),
The outcome of a tank with only 5mm from empty is 0.0192 bar(only 0.278473 of one PSI.)
When my tank is full, the level is 420mm above the Float needle valve seat.
Pressure of water at a 1 meter high head is 0.1 bar
But we are talking fuel/oil mix so multiply 0.1 bar by 0.8 for fuel/oil mix = 0.08 bar
Now multiply that by a full tank head above valve height of 0.420 of a meter = 0.0336 Bar(0.487328 P.S.I.) of pressure at my Float needle seat.
So that is in a
static scenario with vented tank full at 420mm height above valve, Less than half of one PSI.
I would love to know the pressure of a trailered shaken Jerry can in the sun?
As our resident rock hugger has noted
my nephew had a wr400 yammie that used to run for 30 mins then stop... checked the breather ... ball bearing jammed in it. Apparently some ones chookshed was burned down later that nite...
So vibration agitation(whatever) of a
non vented tank of fuel will produce enough vapour pressure to keep the bike in giddy up mode for 30 minutes?
I also wonder how much a sound float needle valve can handle?
Those vacuum pulse diaphragm pumps on Out Boards are rated at 3.5 to 4 PSI(I have tested many of them).
I wonder how much pressure it would take to show up fault in a Mikuni VM38?
Anyhow just all shit hypos'
Come on Mick,
Hey remember when Ji Gantor got the answer for that "what steel are Maico frames made of" but then went boating for the weekend and kept us on suspenders, instead of telling us the answer
