SpudFiles

hi all im new here. i have a gun that was "spray and pray" but i changed it to propane and it doesnt work i used the fuel tool

http://www.burntlatke.com/ft_live.html

and it still doesnt work it was fine as a spray and pray ,this is my first serious gun , my chamber volume is 85 cubic inches ,and my barrel is 32 cubic inches.
any of your help would be very well helpfull

thank you

You may need to change the pressure based on the vapor pressure of propane at whatever temperature.




I would make the meter to work on 50 psi or so, and use an air compressor regulator to maintain that pressure. They were on clearance for $5.00 at Harbor Freight a little while ago, but I think they may have been discontinued. I should have bought more.

whats the volume of your meter? what pressure you filling it to?

I am using like a half of a tank, and my hose is 4 3/8" long not counting the fittings and vaulves and is 3/8" ID, its not working very well, now that i shortened the hose i must blow a little air into the chamber... do u suggest making the hose about 3/4" shorter. thanks o yeah i dont have a regulator should i try to get one

sprayandprayboy wrote:I am using like a half of a tank, and my hose is 4 3/8" long not counting the fittings and vaulves and is 3/8" ID, its not working very well, now that i shortened the hose i must blow a little air into the chamber... do u suggest making the hose about 3/4" shorter. thanks o yeah i dont have a regulator should i try to get one

What??????

sprayandprayboy wrote:half of a tank

Is not a unit of pressure... Please try again

the propane tank is half full

sprayandprayboy wrote:the propane tank is half full

we get that but what pressure are you filling you meter pipe to and how much volume is that pipe?

my meter pipe is the hose it is a high pressure fuel line i dont know how mutch pressure a half full propane tank holds i do not have a regulator, sorry i should have said that my "meter pipe" was a hose.

You've been filling the meter to whatever pressure the tank is? You don't have a gauge on the meter?

Fuel tool says you only need your meter pipe 3.1" long. I HIGHLY recommend manometric fueling, because you will not have potentially massive errors because of a change in temperature.

Uhh, saefroch, I don't think manometric is ideal for a non-airtight gun.

S&P:
As long as you have liquid propane sloshing around in the tank, the pressure inside will be the same (around 120 psi, but varies with temperature).

You don't absolutely need a regulator or a pressure gauge, but it may make life easier. If you could post a picture of your rig that would help us trouble-shoot.

I HIGHLY recommend volumetric metering with a pressure gauge or regulator over manometric metering, especially for a 1x combustion. Unless you want to have a completely air tight chamber that you fill to precisely 0.62 psi for every shot.

Regulator.

several more

yes i still have liquid propane sloshing ... i cant get a piture until friday

Well I guess I don't understand what "manometric fueling" means. To me, it just means "fueling based on pressure," which would indicate the use of a gauge, but the use of an independent metering volume or pipe is optional. I take it that this term normally refers only to chamber fueling?

i dont understand "manometric fueling" is either