Flow Meter

[Daniel's Racing]

None of these flowmeters are actually measuring the flow. They only measure the pressure left after you create a leak by opening the needle. It is just a number of no other relevance. It is a cheap way to improvise but not actually measuring the flow.

A flowmeter that was actually measuring the flow would work at various pressures and still read the same. You could use it to say where any particular combo should run best at(or get it close) versus having to find the setting yourself that works well and using that as a reference to duplicate later on. Still of coarse there would be variables that would make everyone use something a little different but the numbers would have relevance to what is actually able to flow through the needle. At the very least everyone would be dealing with the same numbers every time from every flowmeter on any setup. You could say great I am running the same setup try 5 1/2 and it would be really close on the next guy's flowmeter.

When is someone going to build one that actually is a flowmeter not just measuring the residual backpressure but the actual amount of air/propane or whatever that is being expelled through the needle ?

Something like this but of coarse calibrated for a finer amount of airflow like would be going through a .12 - 1.0 engine needle.

https://www.instrumart.com/products/10204/aalborg-gfm-mass-flow-meters?utm_source=bing&utm_medium=cpc&utm_campaign=Thermal%20Flow%20Meters&utm_term=aalborg%20gfm&utm_content=x%20-%20Aalborg%20Flow%20Meters%20-%20Thermal%20Mass

 

[Matt Schofield]

What's it flow at?

I flowed it 7.5 Terry at 40 on the Mag.
Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[Terry Keeley]

What's it flow at?

I flowed it 7.5 Terry at 40 on the Mag.
Sent from my SAMSUNG-SM-G930A using Tapatalk

Right in the ball park!

 

[Terry Keeley]

None of these flowmeters are actually measuring the flow. They only measure the pressure left after you create a leak by opening the needle. It is just a number of no other relevance. It is a cheap way to improvise but not actually measuring the flow.

A flowmeter that was actually measuring the flow would work at various pressures and still read the same. You could use it to say where any particular combo should run best at(or get it close) versus having to find the setting yourself that works well and using that as a reference to duplicate later on. Still of coarse there would be variables that would make everyone use something a little different but the numbers would have relevance to what is actually able to flow through the needle. At the very least everyone would be dealing with the same numbers every time from every flowmeter on any setup. You could say great I am running the same setup try 5 1/2 and it would be really close on the next guy's flowmeter.

When is someone going to build one that actually is a flowmeter not just measuring the residual backpressure but the actual amount of air/propane or whatever that is being expelled through the needle ?

Something like this but of coarse calibrated for a finer amount of airflow like would be going through a .12 - 1.0 engine needle.

https://www.instrumart.com/products/10204/aalborg-gfm-mass-flow-meters?utm_source=bing&utm_medium=cpc&utm_campaign=Thermal%20Flow%20Meters&utm_term=aalborg%20gfm&utm_content=x%20-%20Aalborg%20Flow%20Meters%20-%20Thermal%20Mass

"Old school" propane flow meters actually do measure the flow in SCFH through the needle and spray bar. The change in flow when the needle is opened or closed is dependent on a constant pressure to be relevant. That flow through the system needs to be adjusted for air density for a good needle setting.

Newer style "blood pressure" type meters work as you say, measuring the pressure created through an opening. They too need to be adjusted for air density.

 

[Mike Hughes]

I gave up on my propane yrs ago. My MAC 84s flow big numbers. So after a couple of secs it would freeze up the value and then it was crap until it was unfrozen. Its kind of cold up in the NW most of the time so it only worked for 1 or 2 races without issues. Boris meter is what I use now. Works great to get you in the ball park and for trouble shooting.