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Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by promodracer, Aug 5, 2014.
Where can I get quick jet area chart to figure my jet areas quicker.
click on jetsize download
its excel sheet
I was thinking of just a chart that lists jet sizes with area next to it. I figure if I calculate the hard way kind my skills and understanding will improve.
What range jets you want chart for? Ii can make you one
Go to Gorrs web site Area chart and gallons for jet size .----lots of good info
How do you know what size the hole is ?
Be very careful of the Ralph Gorr website Jet Flow Charts. According to Ralph his GPM Flows at 150 psi are with water and not methanol. There is a big difference in GPM. The charts are OK for the jet area.
There is a simple area chart on this page in PDF format.
The question was about AREA not water or menthanol--
Ralph and spike flowed my rage pump and i am using his gucci (as he calls it ) bv with idle and stage circuit.
Some where a mistake was made and i was told to increase one jet by .010 Now my pump pressure is only 114 at 8000 rpm. So i have dropped all manifold jets by .002 as i have heat on straps only down to base only. So i want to now calculate total jet area to get a starting point.
So are you thinking my 244 lb pump pressures at.8000 rpm were with water. Or am i confusing things
One more thing i have a 65 lb idle check which seems foreign to k style bv guys.
I did not see it dave. Did you vave some small air bleed deals maybe push locs with plugs for hat.
40 through 70s up to 80.
Mine are all flowed but i suppose thats not relevant.
Ok so whats the best way for me to calculate my gorr flowed jet area. Forgive me im learning.
I would reccomend a flow meter
Jetsize sqin of area
Third one on the list. Hit your "refresh" button a couple of times in case you have been to that page before.
Air Bleeds are on the FI Tools page
The idle check pressure is right according to the info on Gorr's web site (http://gorrfuelsystems.com/uploads/online_manual.pdf). Do not so what we did and drop it to 'normal' bv values or you'll burn something up (we did a piston, which blew out the rocker cover gaskets and pushed oil under the tyres and it went very pear shaped from there...).
Dave gave a link to a great chart but if you ever get stuck without the chart, you can use a little math to figure it out. Pen and paper works but a calculator is quicker whether in hand or on a computer. It's the old πr² or pi x radius squared formula.
So for example, if you have a .100 jet or nozzle, the diameter of the hole is .100. You divide the number (diameter) in half and that would give you the radius which in this case would be .050.
Take that .050 and multiply it by itself. So it would be .050 times .050 which equals .0025. This is the r² or radius squared part.
Now take that .0025 and multiply that by pi which is 3.1415926. How far you stretch out the pi number after the decimal place will slightly affect your final number. Not a big deal, just something to be aware of when comparing.
This would be .0025 times 3.1415926 which equals .0078539815.
Expressed in math it would be: πr² = 3.1415926 x .0025 = .0078539815. You could round this off to .007854 if you like to make it more manageable.
You need memorize pi for this to work easily so that is a drawback to this method.
Alternately, you can use another shortcut way to find what the area is. Multiply .7854 x d² where d is the diameter. So using the above sized nozzle, you would have .100 x .100 = .01. Then .01 x .7854 which equals .00785400. Using .7854 is familiar with most folks as it is used in figuring cubic inches and also for figuring out the volume of the cylinders when cc’ing an engine.
Figuring this out only accounts for the area of the nozzle or jet. The actual hole size may not be the same as what is stamped on the piece or the entrance to the hole may have irregularities that will affect flow. Pressure affects flow too.
If you take water flowed at 100psi x .9868 you get accurate measure of methanol Don't know about 150psi
Yes, that is correct. I have jet area and GPM charts I have corrected to methanol.
Mike, can you please send me a copy of your GPM charts corrected to methanol to firstname.lastname@example.org? (both nozzle and main jets)
I'm getting crazy because I find different methods for the conversion. In my opinion the right formula should be
FlowAlky = FlowWater / sqrt(specific gravity).
Lets say specific gravity is 0.8 so it turns out that
FlowAlky = FlowWater* 1.118
Is it wrong?
EDIT: I'm referring to 150PSI but the conversion should not be affected by the testing pressure