Airdog System

[trapper]

i know this may have been brought up before but i will ask again.......... since i am still working on my project i am looking at a 100gph airdog system, would this work good for my turbo 6.9?

 

[Cincinnati Guy]

An airdog is basically a waste of your money running on an IDI, you will not be gaining anything.

 

[trapper]

i see where you are comming from but all i was seeing it as is a all in one filtration system

 

[RLDSL]

Total waste of money on a mechanical injection system. Those things are designed for these newfangeled electronic injected diesels that fire off an injector via the computer 5 or more times each time teh piston hits the top of the hole, When air gets into the fuel system the pump cavitates and it momentarily sucks air or is pushing against air and winds up with one or more of those triggered openings of the injector being dry fires, so they came with with systems like the Air Dog and other FASS systems to take care of that little problem.

On our old beasts where they only fire one time each time the piston come around, it simply isn't a problem. If it gets to the point wher eit is, then it's injection pump rebuild time. I've even driven 90 miles and forgot to turn my lift pump on and the truck drove just fine until I got up into the mountains where I was pulling hard. THe draw section of teh injection pump pulls pretty good on it's own. There is no need for you to spend half a grand on something to take the air out and boost the pressure

 

[icanfixall]

We really can't use any pressure over about 6 or 7 lbs plus.... all that extra fuel has to be returned to the tank. I don't feel safe in telling you that our return lines can handle 100 gph rate of fuel. If the line is so full of back pressure the injection pump will stop working... Thats how these injection pumps shut down by the closeing of the fuel shutoff check valve by the solenoid... So I'm told...

 

[idiabuse]

so How does one get rid of the air in the line? I dont get air if I have more than 15 gallons of fuel, but when it gets into the front tank I start to get the momentary surges.
Never last longer than 10 seconds and maybe as short as 2 seconds.
Either way I dont like my injection pump getting air.
I have a completely revamped fuel system with all 1/2 line and a holley blue pump with the bypass deleted, using a bypass fuel regulator at the filter head.
In wich it returns fuel to both tanks.
Works great except for the air.

I would like the AirDog too but have too many other projects...

Javier

 

[Black dawg]

Javier, do you have the return line from the filter header to the return tee? It usually helps out with these kind of issues.

 

[rhkcommander]

so How does one get rid of the air in the line? I dont get air if I have more than 15 gallons of fuel, but when it gets into the front tank I start to get the momentary surges.
Never last longer than 10 seconds and maybe as short as 2 seconds.
Either way I dont like my injection pump getting air.
I have a completely revamped fuel system with all 1/2 line and a holley blue pump with the bypass deleted, using a bypass fuel regulator at the filter head.
In wich it returns fuel to both tanks.
Works great except for the air.

I would like the AirDog too but have too many other projects...

Javier

pickup tube busted off in the tank

 

[RLDSL]

i see where you are comming from but all i was seeing it as is a all in one filtration system

If you're just wanting a really good filter system, look at the big truck and marine sites. THis place has tons of them The racor 500 fg is a real good filter seperator if you want to get teh junk out of your fuel before it gets to your main filter ( look under turbulator, call them to find out which one has the element you want in it). If you have room to mount it, I've got a brand new Racor 777R30 that I'd let you have cheap ( cheap is a relative term, but if you were ready to drop $550 on an Air dog, then , it wouldn't look too bad

 

[RLDSL]

so How does one get rid of the air in the line? I dont get air if I have more than 15 gallons of fuel, but when it gets into the front tank I start to get the momentary surges.
Never last longer than 10 seconds and maybe as short as 2 seconds.
Either way I dont like my injection pump getting air.
I have a completely revamped fuel system with all 1/2 line and a holley blue pump with the bypass deleted, using a bypass fuel regulator at the filter head.
In wich it returns fuel to both tanks.
Works great except for the air.

I would like the AirDog too but have too many other projects...

Javier

The stock filter head has a return line on it with a check ball in the line to keep fuel flowing one way ( that is out the line only from the filter head )and if it is plumbed correctly, any air that has found it's way into the system will find it's way to the top of the filter head and bleed itself off via the return line to the tank.
That said, with that fuel pump, your return system is completely overloaded before you ever put your foot on the pedal.
I figured out why a Holey red at 7-9 psi will change timing and a facet dura lift at 10 psi wont, and it's due to the fact that the facet only moves 30 gallons per hour where the Holley moves 97 gallons per hour and our little tiny 5/16 return lines are simply not large enough to handle that much fuel volume. Company truck drivers have known this for years and have carried vice grips with them and when they go out on their shifts, at the first *** stop, the vice grips go on the return line to restrict the flow on the return line, it effectively changes the timing and increases the injected amount and kickes it past the governer about 10 mph, but it'll idle like crap and buck and jump like crazy in between.

The red pump causes a measurable timing change at 97 gph flow ratethe blue has a 110 gph flow rate so the problem is exasperated that much more, and since there is a flow restriction problem that is being introduced into the equation , it is unsure how effective the original factory filter head is going to be at bleeding off air when the pressure differential on the other side of the filter head has changed ( obviously it's not working because too much pressure in the return line if the air is now being forced through the injection pump intermittantly instead of harmlessly going out the return line which is why you are getting the hiccups.
I just noticed you said you ran 1/2" line, but the restriction lies on the engine. The return kit on teh engine holds you back and throws a wrench in the works, it could even cause some major problems, going from a smaller to a larger size return line can mess up the loop sometimes. The system relies on a steady flow, start to finish.

 

[idiabuse]

The stock filter head has a return line on it with a check ball in the line to keep fuel flowing one way ( that is out the line only from the filter head )and if it is plumbed correctly, any air that has found it's way into the system will find it's way to the top of the filter head and bleed itself off via the return line to the tank.
That said, with that fuel pump, your return system is completely overloaded before you ever put your foot on the pedal.
I figured out why a Holey red at 7-9 psi will change timing and a facet dura lift at 10 psi wont, and it's due to the fact that the facet only moves 30 gallons per hour where the Holley moves 97 gallons per hour and our little tiny 5/16 return lines are simply not large enough to handle that much fuel volume. Company truck drivers have known this for years and have carried vice grips with them and when they go out on their shifts, at the first *** stop, the vice grips go on the return line to restrict the flow on the return line, it effectively changes the timing and increases the injected amount and kickes it past the governer about 10 mph, but it'll idle like crap and buck and jump like crazy in between.

The red pump causes a measurable timing change at 97 gph flow ratethe blue has a 110 gph flow rate so the problem is exasperated that much more, and since there is a flow restriction problem that is being introduced into the equation , it is unsure how effective the original factory filter head is going to be at bleeding off air when the pressure differential on the other side of the filter head has changed ( obviously it's not working because too much pressure in the return line if the air is now being forced through the injection pump intermittantly instead of harmlessly going out the return line which is why you are getting the hiccups.
I just noticed you said you ran 1/2" line, but the restriction lies on the engine. The return kit on teh engine holds you back and throws a wrench in the works, it could even cause some major problems, going from a smaller to a larger size return line can mess up the loop sometimes. The system relies on a steady flow, start to finish.

thanks for the reply, I run my holley at 3 psi.
I modified the filter head by drilling and tapping the inlet/outlet to use AN fittings.
I also ran the injector return to the tank return line.
Here is a pic of the filter head with a bypass regulator mounted.

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Javier

 

[idiabuse]

pickup tube busted off in the tank

Oh yes it is, busted off, I fixed it for the first and last time

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[RLDSL]

thanks for the reply, I run my holley at 3 psi.
I modified the filter head by drilling and tapping the inlet/outlet to use AN fittings.
I also ran the injector return to the tank return line.
Here is a pic of the filter head with a bypass regulator mounted.

You must be registered for see images

Javier

The way that is setup, it *should* be sucking any extra air through the return system on the engine via a venturi action when those pipes join back together, but the sheer volume being moved may be botching it up ( heck, that may be the whole problem, it may be pulling so strong on that leg , that it is sucking the fuel away from the injection pump inlet in little spurts,causing it to drop out making you think you were getting air, that would mimic the behaviour of that kind of regulator ). The factory had that system balanced pretty delicate.That's the problem when you start fooling around with speed shop parts. you add one thing to improve, then you have to add another to fix what you improved, then another to adjust the fixed improvement. I'm not criticizing, I used to be ten times as guilty, trust me

 

[idiabuse]

The way that is setup, it *should* be sucking any extra air through the return system on the engine via a venturi action when those pipes join back together, but the sheer volume being moved may be botching it up ( heck, that may be the whole problem, it may be pulling so strong on that leg , that it is sucking the fuel away from the injection pump inlet in little spurts,causing it to drop out making you think you were getting air, that would mimic the behaviour of that kind of regulator ). The factory had that system balanced pretty delicate.That's the problem when you start fooling around with speed shop parts. you add one thing to improve, then you have to add another to fix what you improved, then another to adjust the fixed improvement. I'm not criticizing, I used to be ten times as guilty, trust me

seems as if you understand what I did, that says alot, and it seems you understand what it is doing.
I would agree with you, on a second note, this setup is 2000% better than the botched OEM set up that has others wanting to take their trucks to the shredder

The issue I have with air is really nothing, but you know, we all try to make what we have better, at least some of us do.

Thanks for your input!

Javier