Idle dribblers on a K valve system

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by bigaldart, Feb 27, 2018.

  1. bigaldart

    bigaldart New Member

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    Has anyone a schematic or able to provide a description of how a dribbler system is plumbed. This will be for blown alcohol on a 540 BBC, Hi-Helix 14-71 Kobelco blower with Delta opening. Inlet manifold has provision for two nozzles per cylinder. Thanks in advance for any help you can provide.

    Alan
     
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  2. jay70cuda

    jay70cuda Member

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    WHy do you need a dribbler system. Your setup is pretty similar to a lot of racers?
     
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  3. Mike Canter

    Mike Canter Top Dragster

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    That was going to be my question also but I think I have a drawing somewhere. Let me look tomorrow
     
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  4. bigaldart

    bigaldart New Member

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    Not necessarily going to run dribblers. Just like to have the option available. I also like to understand how things work so a plumbing schematic is step one towards considering things. It is unlikely I will start with them but you never know until you look. Thanks for the responses so far.

    Alan
     
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  5. Blownalky

    Blownalky Top Sportsman

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    Fuel1.jpg Fuel2.jpg Fuel2.jpg Fuel1.jpg

    Can do it several ways. Use the schematic and run two lines to each port from port distribution block(s). Picture of the distribution block is an all in one Gorr. You can use two 8 ports too.
     
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  6. bigaldart

    bigaldart New Member

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    Thanks for that, but surely plumbing it that way would not have the nozzles active at idle as they would still be controlled by the port check and sufficient BV opening.
     
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  7. Mike Canter

    Mike Canter Top Dragster

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    You are correct. You do not want the idle dribblers going through a check valve.
     
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  8. Blownalky

    Blownalky Top Sportsman

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    That’s why I included the picture of the Gorr block. It’s actually three circuits: one for idle with no check, one for dribblers with a low pound/rpm just off idle check and one with a higher pound/rpm check for above off idle. Real numbers are five pounds for the off idle/dribbler circuit and twenty five pounds main for the Gorr block. That again is one way to do it. You could put some of the idle circuit in both the hat and ports or just the hat. PSI recommendations for a screw have three circuits with three sets of checks and two open ports for the idle above the rotors. All depends on what you want to do.
     
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  9. BEDNAR1320

    BEDNAR1320 Member

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    I just drilled and tapped my hat block for the extra lines and ran them to the port dribbler nozzles.
     
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  10. TADHemiracer

    TADHemiracer Member

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    I guess I missed something. I don't see a need or a benefit in a separate idle dribbler nozzle system when the BV has an idle circuit in it already. I see how it would work but don't see a need to have the extra nozzles. After all, how much time do you spend at idle?
     
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  11. TADHemiracer

    TADHemiracer Member

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    And so what if the EGTs are not the same at idle, Stage EGT yes, idles, NO. Just sounds like a more complicated fuel delivery system than needed. Maybe it is just me.
     
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  12. BEDNAR1320

    BEDNAR1320 Member

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    In my application the front cylinders, especially #2 were very fat at idle to the point of going out, if I leaned the BV enough to prevent this the rear cylinders would get very hot 900-1000° at idle. Adding dribblers to the rear cylinders feeding off the hat block cooled them down allowing me to lean the BV and keep the front cylinders from going too fat.

    I guess moving the blower back would help or cure that issue also, but my wide open fuel/air distribution is pretty much spot on. Plus it was less expensive to add the dribblers.
     
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  13. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    Ok, here's my stab at answering a few questions in this thread -

    To do a 16 intake nozzle 'dribbler' system, you would plumb your 'hat' nozzles that would go through the blower the same as you would with a conventional 8 intake nozzle system. No difference up top. The difference is you have two distribution blocks, each with their own check pressure. As mentioned earlier, a typical design will have the dribblers at 5-9 lbs and the ports at 20-30 lbs.

    I believe Tom Conway was the one who pioneered this system. The purpose of this system is with a clutch car, leaving at part throttle to be able to even cylinder temps up at stage rpm. So let's say you have No. 7 where you want it down track, but it's hot or cold at stage. With a 16 nozzle system, you could swap area between the two nozzles to get it where you want it at stage and down track.

    When leaving on the two step, it doesn't do a lot of good. I have played with 16 nozzle systems trying to even cylinders up at idle so they would theoretically be closer at stage, but what a cylinder idles at and what it does at stage are two different things once you get all the fuel and air coming from the blower.

    Brian - I had something similar happen on a customer's car with a roots. The idle was a little too low and the idle check was a little too low. So there wasn't enough system pressure behind the barrel valve to crack the port check. We were down to 4 lbs on the ports and at 1680 it wouldn't have any fuel coming out of the line at idle (we cracked it loose to see). So we got it idled back up where it needs to be (2000 in neutral) and raised the idle check a couple lbs and the back cylinders cooled right down.
     
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  14. BEDNAR1320

    BEDNAR1320 Member

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    Will, I idle at 21-2200 in neutral, idle check 10#, port 26#. Keep in mind I don't have a flow meter, so I have separate lines from the K valve to the hat block and port block.
     
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  15. bigaldart

    bigaldart New Member

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    Great information people, thanks to everyone. Now I have a mental of picture of how it goes together should it be needed. Will in particular for that insight into dealing with idle distribution by raising check pressure. Thank you vry much.
     
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