spray bar

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by bill, Dec 26, 2016.

  1. aj481x

    aj481x Member

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    A little surprised the subject of fuel pressure has not come up in this discussion, certainly affects atomization.
     
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  2. TOL

    TOL Active Member

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    You must have been reading my mind. Those nozzles are impingement style (Bete for example), fixed orifice jobbies. Pretty small turn up/down delivery ratios possible.
     
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    Last edited: Jan 5, 2017
  3. Blake

    Blake New Member

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    I have been following this thread for a while and pardon me for bring this up but, why wouldn't you put an EFI system on the engine. You can maintain constant pressure on the valves/injector with Waterman nozzles that have a great spray pattern and atomization. You can adjust the amount of fuel going into the hat at different parameters. You can get injector sizes from 350lbs/hr (1400lbs/hr with 4) to 1000lbs/hr (4000lbs/hr with 4). There are 4 outputs each 90 degrees apart so from 25% to 100% you will have a continuous spay into the hat. You can adjust the amount of fuel by RPM and MAP so the proportion of fuel and air can be the same in the hat and thru the blower into the plenum or you can slope it up or slope it down with RPM change or boost change and adjust the port injectors so that you have constant GPM vs Boost pressure, which I think Mike is dead on with what he said other than when the Cam starts to rollover (which you can adjust for with EFI). Plus you get cylinder by cylinder data to determine where to go next, you are not going in blind about how much to put up top vs down below. Just something to consider and banter about or ignore.
    Blake
     
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    Last edited: Jan 5, 2017
  4. TOL

    TOL Active Member

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    Hi Blake. I agree with you about the total ECU control thing. My direction too, as you and I have discussed.

    The "spray bar" concept is mainly aimed at inlet air densification through evaporative cooling. You can use EFI components, with an ECU, to feed MFI nozzles (ie: Waterman), but you don't really get the same cooling effect, as the atomization from the MFI nozzles is relatively poor in comparative terms. What I am working on right now is a way to create the same effect as a spray bar, yet with nothing hanging in the wind and with a wide dynamic turn up/down ratio controlled by the ECU. It has been interesting to see how the baseline mechanical spray bar approach has worked out so far.
     
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    Last edited: Jan 6, 2017
  5. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    It is legal again in PX, but from what I heard talking to the PX guys that tried Nitrous on a screw blown motor a few years ago - was that the main advantage was from the nitrous super cooling the injector hat charge.

    Not a nitrous guy but I was always told Nitrous works best with gasoline.

    I think this was more or less what they did years ago when they had nitrous on the Nitro FC's.

    In other news - in regards to spray bars - my sources tell me a spray bar behind the throttle body was one of a certain PS team's major advantage. Finally other PS teams started buying intakes from said sponsor/mfg. At the end of the year this was ruled 'not within the spirit of the rules' for PS.

    Not directly on topic, but fuel to the fire...
     
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  6. Blake

    Blake New Member

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    TOL,
    I agree but, let's approach this differently. Does it really matter. Methanol evaporates at 148F, going though the blower how much will be left in liquid form that would be different between the waterman nozzles and the spray bar?
    In the hat plenum how much more air do you think can be pulled in by cooling the charge compared to how much volume is being displace by the alcohol being discharged by the spray bar?
    Let me try to explain without getting too technical. The latent heat of evaporation of water is 540 Calories per gram of water evaporated. Methanol is 264 Calories, Gasoline is 76 Calories (typical). It takes on Calorie to raise one gram of water 1 degree Centigrade (background).
    I don't think it matters much if the Methanol evaporates before going into the blower or in the compression cycle of the blower. I admit technically it is better before the blower the difference is very small, what matters is that it does get evaporated and cools the intake charge.
    With that being said how much is there to gain by being able to adjust the amount of Methanol in the hat verses the constant flow of the spray bar? I do not have experience with the spray bar but, have a lot on the EFI side and I think the amount of flow into the hat matters queit a bit. Too much is not good and to little is not good. Too much and the Methanol does not evaporate, the intake air is displaced and the maximum amount of air intake is not achieved and the fuel clings to the walls of the intake manifold. Too little and the intake charge is not cooled enough and the air density is lower than it could be. Both cause the loss of power in the engine.
    Ideally having a spray bar that is adjustable would be best, I think EFI is second best because you can keep the pressure on the nozzles high (good atomization) and control the amount of fuel going into the hat at the same time.
    Are people claiming they are getting more power from the spray bar because of the atomization/evaporation of because they are now closer to adding the correct amount of fuel up top?
    Blake
     
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  7. Blake

    Blake New Member

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    Will,
    That is interesting, I can definitely see how that could really help a PS engine. Nitrous is great for cooling the intake charge and that helps tremendously. I will be very interesting to see if Nitrous gets tried or works out on the PDRA Pro Extreme class.
    Blake
     
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  8. Mike Canter

    Mike Canter Top Dragster

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    Blake, I disagree with you. I have tuned the motor with and without the spray bar. I know when the mixture is correct based on the plug readings. I also have a manifold temperature sensor. I know what is going on. The fuel from the spray bar lowers the intake manifold temperature which lowers the density altitude within the motor which requires more fuel to make the AFR correct and results in more power.

    Also, nitrous has been tried in PDRA PX class but rule change now limits it to a single power adder.
     
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    Last edited: Jan 6, 2017
  9. Blake

    Blake New Member

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    Mike,
    I am not the best at conveying ideas and thoughts in writing but, I don't think I was disagreeing with you other than the thought of I think it would be better to be able to control the amount of fuel coming out of the spray bar without changing it's atomization effect for certain conditions the engine is seeing. My second choice would be constant flow. I completely agree that having a spray bar is better than not having a spray bar and yes it will do everything you said. Not trying to back track either the question is can the waterman nozzles be manipulated to work almost as well as the spray bar or could the spray bar be hooked up to an 1000lbs/hr injector with a check valve to be able to control the amount of fuel coming out of the spray bar? I think it might be worth something to keep adding fuel to the hat as the RPM goes up.
    Blake
     
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  10. Mike Canter

    Mike Canter Top Dragster

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    The amount of fuel coming out of nozzles and the spray bar on a MFI system is not constant. MFI systems are not constant flow systems. The fuel pumps are calibrated to match their output to engine rpm. The higher the engine rpm the more fuel is pumped out. We tailor this output to match the boost by using a main jet, pump loop circuit and fuel bypasses. Yes you could replace the spray bar with an injector. I believe that once the engine rpm gets high enough so the fuel pressure gets above a certain point we always have atomization out of the nozzles and spray bars.
     
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  11. JustinatAce

    JustinatAce Member

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    Power gains can typcially be seen more down-track. Early in the run, we have torque multipliers to get the car moving, so you may need to adjust those settings to get the car off the starting line. Biggest changes you see in power gains when the rest of the car is setup to use the power are in the splits from the 60 to 330 and further as well as MPH. If you're going faster, it should take less time to cover the distance as long as the car is going straight.
     
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  12. bill

    bill Member

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    so mike how much difference in the intake temperature is it with and with out spray bar
     
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  13. TOL

    TOL Active Member

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    Blake, it all really boils down to two considerations for a screw compressor, namely:

    1) Are you trying to densify the inlet air mass flow into the screw in order to maximize the total air mass air flow through the screw? Remember, once the rotor volutes close (compressor inlet cycle over) all you can then do is influence temperatures from that point forward.

    2) Or are you trying to simply control the enthalpy of the combined mass flow out of the screw at the discharge port, into the intake manifold of the engine?

    Those are really two different tasks, and they warrant two different sets of considerations/attention.

    When we run fuel (methanol in this case) through the screw, it causes the screw to behave more isentropically and less adiabatically than initially intended. The PSI screw is nothing more than a dry single stage industrial screw compressor which is being forced into coolant flooded mode via the introduction of a volatile coolant (methanol).

    It all depends what a person wants to accomplish, and what else is going on in the big scheme. Do fixed mechanical spray bars work? Yup. Do they have a wide dynamic range or easily adjustable turn up/down ratio? Nope. Would having a wide turn up/down ratio be desirable under ECU control? Yup. Should a person want to map out the flow of the hat fuel, apart from the port fuel? Yup.

    An argument could also be made, in certain circumstances, that no evaporative hat cooling is desired during the inlet phase of the screw. It all depends what you want to accomplish.

    From the engine's point of view it all boils down to what's going into the cylinder and being trapped behind a closed intake valve. There are lots of steps between the hat and the chamber. In the case of MFI, no control over those steps or stages. In the case of an ECU, varying degrees of control depending upon how you set things up. Remember, all the engine really knows is what it has to work with near TDC behind a closed intake valve.

    Hint. Think about having two pumps, and two control loops. One for the hat, and one for the ports. You can then do different things with each as opposed to one simply being a proportion of the other.

    It's kind of cool thinking about all of this stuff !....
     
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  14. Blake

    Blake New Member

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    TOL,
    I completely agree with you, ideally a completely homogenous fully evaporated charge going into the blower, screw or roots would be the best as the incoming charge would be at it's densest point. This is not really possible on a car. The goal is the get the densest charge and homogenous as possible into the cylinder before the intake valve closes.

    I think the spray bar is great, can we make it better? I do have two systems running in the ECU code one is open loop only for the hat and the other is selectable open loop or closed loop for the runners. Since it is not practical, therefor not possible to have a completely homogenous completely evaporated charge in the hat before the volutes close, I think it is best to aim for a completely evaporated charge coming out of the bottom of the blower, liquid methanol at this point costs power because it displaced air that could have been ingested into the intake of the blower. The amount of charge that it takes to do this is absolutely not constant and the orifices of the spray bar are not nearly as linear as the nozzles in the runner so the spray bar can not be set for ideal conditions other than one spot in the RPM/DA, water grains and other minor factors. I personally think that water grains might not matter so much up in the hat as compared to the runner inlets.

    The purpose of all of this is can we go faster/generate more power and keep parts alive. What is happening in the cylinder is a stratified charge which is why the motor runs better and is more responsive. With the spray bar the homogenous evaporated charge in the cylinder is much higher with it than without it. I know we can do a better job with EFI but, are we there yet and is it possible to merge the two. We have done both screw blowers and roots blowers, the way it is described above and have had great success, it can always be done better though.
    Blake
     
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  15. TOL

    TOL Active Member

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    Agreed.

    Using conventional thinking, the spray bar is just a tiny step forward, at least in the form that it has been applied thus far.

    Circle back, and notice what I said earlier about two pumps and two control loops.

    What could a person do with a smaller amount of hat meth at 500-700 psig on tap? Maybe even add external air atomization to help as well?

    That should plant a few seeds without giving away the whole farm :)....

    Actually, stratified charge in the cylinder is exactly what we want at the time of IVC. We want liquid vaporization to be continuing right through to, and past, the point of spark ignition. Part of the essential process in these solid motors. The trick is to have enough vapor to work with though at the same time.

    Thanks Blake.
     
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    Last edited: Jan 9, 2017
  16. Blake

    Blake New Member

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    TOL,
    In my opinion the two pumps must remain separate and one must be open loop or you would create a large oscillation between the two.
    We have tried a aerated waterman nozzle to great success, for simplicity we fed it from the plenum under the blower, you could use a bottle to get more pressure. 500 to 700psi would be great for atomization also probably better than the spray bar. Turn on time would be an issue but, I know how to deal with that with giving away the farm either.

    Yes, a stratified charge with the right proportions is always best. As long as the droplets from the runners are not to big. One problem with meth is that because the latent heat of evaporation is so high, as the outer shell of the drop evaporates the inner droplet cools and that makes it harder to evaporate. This is one advantage gas has over meth but, stratified charge works very well for gas engines.

    Could go one but, probably starting to bore everybody with this crap.
    Blake
     
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  17. jody stroud

    jody stroud ZOMBIE Top Dragster

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    This is what what the inside of a hat with a spray bar looks like...... If it shows up clear.
     

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  18. h2b puller

    h2b puller Member

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    Here is a link for seeing the spraybar on Mike"s flowbench.

    what i"ve seen on pulling engines with the spraybar it"s very hard on the rotors and teflon below the spraybar (is this normal with the spraybar or ?
     
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  19. Mike Janis Jr.

    Mike Janis Jr. New Member

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    Hi guys! Great read on this topic! Awesome discussions and thoughts. At Mike Janis Superchargers we are always working on innovation. Trying to come out with the newest designs and products for our customers to be able to set records and win races. We have incorporated our fuel deal into our MJ All Billet 2 Hole Dragon Slayer Injector Hat......I can tell you first our setup is not like the "Spray Bar" everyone is referring to here. Our setup doesn't fall off in horsepower in the upper RPM bands (not only on our dyno, but on customers who have dynoed our setup they see the same thing). We have spent a lot of time in R&D to get away from the traditional deal everyone is referring to. We have been using this setup for many years....now it is just more noticeable with our new hats. We have around 50 hats out there in the market now over the past 12 months time and the customers have been extremely happy, which means we did our job. Not only have we been able to incorporate a built in fuel deal into the hat all in one piece, our hat has allowed for one of the best flowing shapes to let the air enter the supercharger. (See attached picture) We will continue to develop the best products we can at Mike Janis Superchargers. Thanks! Any questions or interest in our products please email me at mikejanis1065@gmail.com or call at 716-628-2591.
    #MikeJanisSuperchargers #AmericanMadeHorsepower #GotBoost?!?

    Mike Janis Jr.

    PS Thanks Will Hanna for the awesome place where people can speak!
     

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  20. jody stroud

    jody stroud ZOMBIE Top Dragster

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    Ran same strips and coating for a whole season for the last two years. No problems with either. One was a SSI blower and one was a Hammer Supercharger.
     
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