Injector tester

saw a small flowbench for testing flow in injectors or jets in ajs trailer. any idea who makes this ? looks real nice to do a quick check on a injector to see how it flows. this was smaller than a shoebox in size. any ideas and how much this cost?

 

Just use your leakdown tester.
Jeff

 

How do you do that ?

 

Basically your leak down tester is a flow meter. Our alcohol dragster engine idles at about 50 lbs fuel pressure so I use that as my reference on a dual gage leak down tester. Hook up a step down to a -3 fitting and leak the nozzle you want to change; lets say it leaks 30 psi at 50 psi input pressure. Then leak the nozzle in the direction you want to go...to richen the cyl you want a new nozzle that will leak lower at the 50 psi input pressure such as 29 psi at 50 psi input pressure. When the output pressure is lower at the same input pressure it is flowing more volume and the secondary pressure will be lower. You will be stunned at the variety of flows that the same number nozzle will show.
For small changes move 1/2 to 1 pound pressure at a time. Ignore the nozzle number, pay attention to the flow number and then look at what the egt change is and move from there. Just make sure you go in the correct direction...at 50 psi, lower secondary pressure is more flow and higher secondary pressure is less flow. Good luck, let me know how it goes.
Jeff Johnsen

 

I might be wrong here but don't air flow different than alcohol?..Dave

 

You are flowing a nozzle that you want to change with air and you are flowing the one you want to change to with air. You are looking at the change flowing the same media.
Not only that the cop beside the road is very happy to check your alcohol by flowing your air........
Jeff

 

injector erector

funny enough, thats what ive been doing lately. i made a custom leakdown with about a .150 orifice in it and 8 hoses on it so i can flow all 8 at once and compare the total flow of 8 vs 8 others. the only thing is i cant figure out, i have a 80 jet that should read 20percent leak, but it doesnt its 84 or so. with either a stock .040 orifice tester or my big flow one. using the airflow seems to be a accurate way to test, but we just sent 8 nozzles off to be flowed and replaced with 6 that flow the same, and got a huge change in the rich side with the ones sent back. im not sure what to think. is my air method not working, and wet flow is more accurate, or should only wet flow in gpm only method. i do see a lot of difference even with the same number jets like you say,so something is working right. ive used leakdowns on engines for years and they seldome lie to you. any ideas? maybe this guys flowbench is off too?

 

I did not intend to suggest that the air check method will give you a gpm factor which a flow bench configured to flow a nozzle or jet will. It will however give you a very accurate comparison of one nozzle to a similar sized one and allow you to richen or lean a single cylinder to a very fine and accurate amount. I see changes I make down to as little as 20* at stage or high gear depending which nozzle I'm adjusting. I do also flow 2 nozzles on a single cylinder together when I want to change both to adjust both stage temp and high gear temp....like if it is cool early and hot late and I have to change both, I flow each individual change and then both together to ensure my total is correct for what I want.
I do not flow large numbers of nozzles together; as you indicate, a conventional flow meter, with it's oriface restriction might go wonky if you do not have that sized correctly and perhaps if the air supply had an inadequate volume. In my view I am in deep enough water dealing with one cylinder at a time and the only time I consider all the others when I'm adjusting one is if I'm concerned that I've made enough changes to affect the others due to orifice area/fuel pressure change. Having said that I do change several nozzles at a time if it is required between runs but I do pay attention to the total area change.
I have used a friend's wet flow bench and did so just after he had had the 2 flow meters on it calibrated at substantial expense....we flowed a pump through one meter and then through the other and they were approaching 2 gallons different...he was not happy. The moral that I took from that is that it is just a number and we want to ensure that each little change, in real time in the real world is what we intend it to be and then we look at our dyno data...the race car computer output and the et slip to see if it helped or hurt us. My best advise is to look at each cylinder as it's own little engine and deal with each one on it's own, just like your children. They each respond to something a bit different from the others....does #6 or #3 like what the others like? No, so deal with them as individuals and try to make each one be all it can be even if it is a bit different from most others.
Jeff

 

exactamundo

that sounds pretty fair reasoning to me. i see there is many ways to approach this, just as long as u understand what your doing with the changes and how u measured the change. makes total sense to me . thanks for the advise. appreciate it.

 

Sid Waterman Tester

http://www.watermanracing.com/Pages/flowbench3.html

A real trick piece.

Steve

 

Here is what i use. In my jet box, i keep a chart of the air leak of each jet. I've seen WIDE spreads in what identical jets flow.

This is a -06 <-> -03 reducer, and a -03 <-> -03 female union. Connect to leak down tester, use standard -06 leak down hose.

 

this has been a great thread..1 question do you have to use a orfice..'jet' of some sort I have a single guage leak down for my BV is it ready to use as is? it came with all the hook ups for nozzles ect. its a kinsler I think?..thanks dave

 

leak me

all the single and dual gauge leakdown testers usually come with a .040 industry standard orifice built into the gauge. some of the larger ones come with a .o60. with this in mind as the thread suggest, it is ok to use either to flow a single jet to get readings, but if you gang say 4-8 jets on it, the orifice will be too small to support the larger area of the jets together. the one i built from a earls erector set i put a very large orifice in it, and can do batches of 8 to see all 8 total with no restrictions. the reading isnt anything i can corolate to a single jet reading as far as i can tell, but its a good test to back up any theories if you are getting variances in a batch of jets marked the same, but really dont flow the same as many people have found out like myself. i guess the best thing of this, is its a cheap easy effective way to do a backyard check without spending a ton of money to pay somebody to tell u the same thing. my only question i havent had answered is i am trying to get a industry standard jet to calibrate or check the leak gauge to see if anythings changed, but havent really got that .080 supposed theory leak to work out yet.

 

Greg, I use the same for the Top Fuel cars...

EDB