GM LE2 engine conversion

Discussion in 'Chevy' started by Chris Matheny, Dec 11, 2019.

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  1. Jan 7, 2020 #41

    Jazz30-06

    Jazz30-06

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    A recommendation, if I may. I would run all injectors all of the time if you can control fuel well enough. That way you can switch to whichever is still a "good" bank if need be and know they were firing previously.
     
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  2. Jan 7, 2020 #42

    Chris Matheny

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    I had thought about that but with the complete two Lane harness and ECM setup I'm planning it will not work. I'll likely just fire the engine on the one system to make sure everything is good then switch to the other system for flight just like checking mags/plugs before takeoff. All plugs will be firing all the time but will have a check to momentarily kill one set then the other to check plugs and coil packs.
     
  3. Jan 8, 2020 #43

    Chris Matheny

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    Well, while milling the top off my valve cover tonight I moved the setup back to final cut the areas under my clamps and ran the valve cover right into my Z axis way covers and broke the valve cover casting. Good thing I have another one I will cut tomorrow. This will then be used to make a plug and mold for the carbon fiber valve cover. Ahh one step forward and two back. I did get all my locations finalized for the sheet metal intake manifold flange.
     
  4. Jan 8, 2020 #44

    cheapracer

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    Covers these days are often an integral part of the head's strength. You might want to check that with GM.

    Then there's the heat transfer factor, valve covers are also often an integral part of that scheme as well.
     
  5. Jan 8, 2020 #45

    Chris Matheny

    Chris Matheny

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    Luckily that's not the case here. It's a big part of the PCV system that I will not be using their setup.
     
  6. Jan 9, 2020 #46

    Jazz30-06

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    Wait, you're running two completely seperate EM systems?
     
  7. Jan 9, 2020 #47

    Chris Matheny

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    Yes, two ECM's on all separate sensors and injectors.
     
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  8. Jan 9, 2020 #48

    stanislavz

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    How do they know, to add twice the fuel, when one is dead ?

    + alive one, have to shut down power from dead ecm - mosfet 99% fails as short circuit, so, they will flood engine.

    And for full power you do need not 4 injector at all. Multipoint injection is necessary for low power only.

    So - i would go for two tbi injector, one per ECM, and some sort of "watchdog"
     
  9. Jan 9, 2020 #49

    Chris Matheny

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    Only one ECM and set of injectors will be active at a time. If in flight any one point of failure occours you will be able to switch to an entirely new system for safety.
     
  10. Jan 9, 2020 #50

    stanislavz

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    I was installing aftermarket ecu in high schools for some years - i would not like this solution. The biggest show stopper was sensors/vonnectors. Sometimes - lost sync due to emi. And you cant just on the fly swith on/off ecud -You still need an time to sync timing whell. Plus sparks dont like to be left cold. I suggest to ru ecu all time, just turn on/off only injector banks. Coils hot all time.
     
  11. Jan 9, 2020 #51

    stanislavz

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    And i do think from time to time on magneto like electomechanical fuel injector - mechanical low pressure fuel pump, normal injector pulsed from magneto like coil. Sorry off-topic
     
  12. Jan 10, 2020 #52

    Chris Matheny

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    All coils will be hot and all plugs sparking every time. The switchover from one ecu to the other would not be on the fly. If engine died in flight it would be a simple switchover and restart situation.
     
  13. Jan 10, 2020 #53

    Toobuilder

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    At 300 feet over trees on the departure end of the runway a simple switchover/restart might burn more time than available
     
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  14. Jan 10, 2020 #54

    stanislavz

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    Shall i draw a circuit for it ?
     
  15. Jan 11, 2020 #55

    Chris Matheny

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    This would hold true in a certified engine also.
     
  16. Jan 11, 2020 #56

    Chris Matheny

    Chris Matheny

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    Location for the secondary crank sensor machined. Clears flexplate.
     

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  17. Jan 23, 2020 #57

    Chris Matheny

    Chris Matheny

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    Got all my big parts of my redrive done. Now I'll have to get the shafts splined. There is some room to shed weight on it after proof. The second prototype might be a casting, time will tell.
     

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  18. Jan 25, 2020 #58

    Jazz30-06

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    Why change to a casting? You already have the billet piece which should be more uniform in structure and therefore stronger/lighter.
     
  19. Jan 25, 2020 #59

    Chris Matheny

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    I will only change to a casting if this box proves itself and there is a market. All bearing, shaft and gear loads are designed around a 600lb-ft at 2700 with a 2000hr TBO and 99.9% bearing reliability. I should be testing it in the spring on a stationary test engine. Time will tell. There have been smarter designers than I fail but it will be an learning curve on the 3 designs of torsional vibration mitigation I have in my pea brain.
     
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