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  • Users: PFM
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  1. PFM

    EFI Fuel Plumbing

    Pat, I have seen you on this board for years, thanks for the reply. I have one of those early flat fours with FI. They could not be considered high performance and this application is. I have heard all kinds of stories about fuel delivery problems, resonance troubles etc. just trying to find...
  2. PFM

    EFI Fuel Plumbing

    All, There will be a return line from a distribution block(s) located within 3 to 4 inches of the injector. So fuel line from pump to distribution block, hose to second bank distribution block, hose to regulator and bypass to tank. From each block are three lines 3 to 4 inches long -6 hose to...
  3. PFM

    EFI Fuel Plumbing

    All, Long time no visit. I am working on a flat 6 cylinder (Porsche) adding a second set of injectors. Due to location a "fuel rail" is impractical and this prompts my question: Are short fuel lines (-6) from a central supply block a big problem? I do understand the fuel in this line is...
  4. PFM

    Fuel Injector Specs

    Warpspeed, Well yes and no, when you fab all your parts making the injector fit is not all that bad. I did find this great link on another web site http://users.erols.com/srweiss/tableifc.htm THis was the info I was looking for. Regards, PFM
  5. PFM

    Fuel Injector Specs

    Hello all, I hope someone here has detailed info and flow rates for a wide variety of fuel injectors. A link to a web site with this info would be just fine. I am trying to make some good decisions on a purchase and this info is all but impossible to find, so far. Thanks, PFM
  6. PFM

    ASMI Flow Nozzle

    Hello all, Please help the rookie with a question, I have several ASMI Nozzles I know they were used on a high end air flow bench, I have some doccuments on them but no CFM numbers. The info is as follows, Effective Area .484823, Actual Pressure Ratio 1.049138, RH? 38.24, Mass Flow 0.071831...
  7. PFM

    4-VALVE HEAD - OPTIMUM PORT VELOCITY??

    V114, I envy your project. OK if the carb flows 270 CFM at 12" it would flow 413 CFM at 28" in a perfect world. I would want to flow the head first with a radius inlet at max valve lift plus .1 inches (for good measure), then add the intake manifold with a radius inlet, it should be within -1%...
  8. PFM

    Horsepower Per CI vs VE

    Hello all, I am trying to find a correlation between Horsepower per cubic inch and Volumetric Efficiency. I read that some prostock engines are making better than 2.5 HP per cubic inch at 9000 plus RPM. Is there a path back to VE from this as a start? It's the math problem again :-( PFM
  9. PFM

    Valve Float Due to rapid Acceleration

    All, Do I feel a shift here? Strokersix I think you are with me somehow they add to each other. I think the math is beyond my old brain, too many years since those parts had to work. Ivymike, is there room in one of those equations for engine acceleration to have an effect on valve float? I do...
  10. PFM

    Valve Float Due to rapid Acceleration

    John, "It is simply not possible to accelerate the valve more rapidly on the way up to maximum RPM, than it is accelerated while operating at maximum RPM." You state that with such conviction. Though IvyMike has given me an example I think I can live with I still have some issues I cannot...
  11. PFM

    Valve Float Due to rapid Acceleration

    Mike, Thanks for bringing out the 2X4, sometimes when my record gets stuck it needs a tap back to reality. The car deal got through my fog and made the point. Rod, As for your cam and not floating the valves with a flick of the throttle well that is a whole new thread too, what if the valve...
  12. PFM

    Valve Float Due to rapid Acceleration

    Thanks all, The input has been great but I still see no clear answer. Let me push the example a bit further. I hope my math is good. Again we accelerate the motor from 4000 RPM to 8000 RPM but this time in .0070 seconds. The valve and spring package is good to 8500 RPM. My math says at 4000 RPM...
  13. PFM

    Valve Float Due to rapid Acceleration

    Franzh, You are right, I am looking at a snap throttle type acceleration, or a low first gear launch at the drags. I still see the potential for the motor to accelerate at a rate higher than the given RPM. Thanks for the post. Dave
  14. PFM

    Valve Float Due to rapid Acceleration

    Norm, Thanks for the link, it is on the right path. I am not convinced that Pat is correct. I guess the answer may be in the instantaneous acceleration vs the average we call RPM. I have not been able to prove this (with math) one way or the other to my satisfaction. If we push my example to an...
  15. PFM

    Crank reference angle vs. timing errors

    OK I follow the logic trail on this just fine, dare we assume ( I do hate to use that word) that this would affect any delay based ignition / EMS system that uses few pulses per engine revolution? I called MSD today and got no solid answer. If you want a real scare, I helped configure one of...
  16. PFM

    Valve Float Due to rapid Acceleration

    Pat, Thanks for the reply but this is not due to tach lag, the data AQ does not miss much. The ignition changes are not due to torsional distortion either take a look at thread 71-107708. RPM is a very slow dimention "Minutes" as opposed to Micro seconds requied to accelerate an engine. If we...
  17. PFM

    Valve Float Due to rapid Acceleration

    All, I have seen in print an article discussing valve float due to rapid engine acceleration at an RPM below that at which valve float occurred under a slower acceleration rate. I have seen evidence of this in engines on track that used low gearing and hard acceleration. I believe I have seen...
  18. PFM

    Oversize Piston Rings

    Swall, I have seen this done with OK results and terrible results, I stay far away from terrible results. I run air cooled Porsche stuff, and follow the engine spec for ring gap. What is the cylinder bore material? The hone finish is also inportant for ring seal for the specific ring and bore...
  19. PFM

    Who here really knows how to make BOOST?

    ijs12fly, If you can add an injector ( in the rules) before the turbo, on the exhaust side, you can add fuel and spool up the turbo. This is the method used in the WRC cars someone already mentioned to prevent turbo lag. You may want to look at Greddy for a controller for the injector. I am...
  20. PFM

    Results if I join Viper plenums..?

    Viper488, "There's only air in those plenums, so the only thing the joining is going to provide is air (lean)without changing the programming. The whole idea is to gain flow. If there is a gain in the dry flow from the plenum through the runners, it's going to ceate a lean condition isn't...

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