Port Nozzel pressure

we set our barrel valve by using manifold temp.

 

Interesting!

How have different blowers or engine combinations compared?

 

I was taught to check the leak with the lines disconnected. But, that's not the way the motor runs. So I check it with them connected. I believe it's a truer reading.

 

Port nozzle pressure

What is the purpose of running a poppet in the port nozzle side of the system?

 

Port nozzle pressure

Thanks Mike, I thought it may have had something to do with that.

 

if the blower is getting hot at idle (I haven't checked it with a temp gun but it is very hot quickly) , does that mean that poppet is set too low?

 

I think your confused. Port fuel is below the blower, so it has nothing to do with how hot the blower gets. If your blower is getting hot at idle, then you need to add some area to the hat nozzles or increase the BV leak.

 

hmmmmm,
I think Lucky is right on. With the port nozzles on at idle and definitely the hats are on, compare this to only having the hats on. The blower will be cooled more by having the ports off at idle.
My $.02
Lucky, maybe you should put your system on my flowbench?
Maybe in the dead of this next South Dakota winter you could bring it up from cozy Arkansas

 

I'm glad I found this since I am just getting into blown alcohol. I'll be searching other threads about fuel systems and following this as well.

1 question though. I havent even bought my setup yet, but I will have it all very soon. So I dont know anything about this stuff yet and am learning.

How do you actually do this leak test? If you are checking to see what it is at idle and the lines are all unhooked " or still conected " how do you turn the pump? Is this something that has to be done off the motor?

 

Here is a link to the one that I have and use. I got it from Good Vibrations:
http://goodvibesracing.com/barrel_valve_leakdown.htm

 

aahhhh. so your testing with air and not alcohol. We test our gas all the time since we run nitrous, but we use the feul itself and get flowing pressure. Thats why I was confused. Looks like I will need to get a gauge set.

Thanks

 

Putting Mike's response in your and my "easy to understand" terms
Using air to do a leak down test will not show a result much different than if you figured out how to do it with whatever fuel you use. (gas or alcohol). Mike is just saying the test is just telling you an approximate "percentage" of leak-by when the barrel valve is in the closed position (idle). In other words, how much gas / alcohol is getting to the hat when you are sitting at idle with the throttle closed. It is a reference percentage for you to use to get your system set up initially whenever you have made a change. I know , I know, now I am making this sound complicated. Use the percentage as a starting point, adjust from there.
Example:
You remove the hat and disconnect the linkage, the butterflys have to come out so you can reach the bolts behind them. You need to get it bolted back up and you have no clue where your barrel valve linkage was set. ....... set it back to that original leak-by percetage and you have a great starting point!
Sorry, I truly made this too long and drawn out but .........

 

it's all good info.

 

I know, ......... that's why I love this place!