From: "George Lendich" <lendich@optusnet.com.au>
Date: 2005/08/19 Fri AM 04:44:34 EDT
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: Injectors

OK Chaps,
The local supplier can supply LS1's and hopefully their the same type you all refer to as he doesn't have them in stock and has to order them in.
Is there anything to reference what they supply against i.e. markings- any one have a photo of LS1's.
Can you estimate a price on LS1's, which I can do a comparison, as the price given was rather expensive.
George ( down under)

  Ed, Dave and Tracy,
  Thanks a bunch!
  I'm trying to source alternative parts for the Aussie situation, wherever it's possible.
  I will try for the LS1 coils locally.
  Will get SATURATED Injectors.
  Any recommendations on fuel pumps - flow rate or other things to look at.
  I think Tracy's preference is for a particular type ?
  George ( down under)

  ---- Original Message -----     From: Ed Anderson     To: Rotary motors in aircraft     Sent: Thursday, August 18, 2005 9:38 PM
    Subject: [FlyRotary] Re: Injectors


    Hi George,

    Unless there is a new type of injector on the market, most injectors have a fixed impedance (resistance to current change).  They are generally classified into two categories -  Low impedance or High impedance.  The low impedance generally have a resistance (measured by Ohm meter) of around 2 - 3 ohms and are also referred to as "Peak and Hold" type injectors.  These type use an initial surge of higher current to "yank" the pintel open and then the current drops to a lower sustained level to "Hold" these injectors open for the rest of their ON time.   The second type - High Impedance injectors -generally measure from 14-16 ohms and are also referred to as "Saturated" types.      The basic difference is that the "Peak and Hold" have a bit longer open time (for the same duration pulse) because the initial higher surge of current "yanks" the pintel open quicker than the steady sustained current of the "Saturated" type injectors.  The peak and hold type are often found in the higher flow injectors used by racers.   IT could be that the salesman was talking about the "peak and Hold" type as the current does change during the pulse driving it.

    The key and important thing is that (generally) an EFI system that is designed for the higher current of a Peak and Hold injector can also safely  drive the lower current Saturated type .  However, many  EFI systems designed for the Saturated type run a risk of damage (due to the higher current requirement) if they try to run the lower impedance Peak and Hold type.      To really make it confusing - Mazda used both types in various years/models of the 13B.  It really doesn't matter what Mazda used as much as making certain YOUR EFI is matched with the proper type of injector.  Tracy's EC2 can drive both types, however, you will need some resistors (5 Ohm, 25 watt as best I recall) if you use the Peak and Hold type injector in order to limit the current draw.  No resistors needed if you use the saturated type (higher impedance) injectors.

    So if there is some EFI system that changes the impedance of the injector - its news to me.  Hope this helps.

    Ed
      ----- Original Message -----       From: George Lendich       To: Rotary motors in aircraft       Sent: Thursday, August 18, 2005 3:26 AM
      Subject: [FlyRotary] Injectors


      OK Chaps,
      You know I know nothing when it comes to electronics and things, but I have to ask some questions OK!
      I contacted BOSCH for Aussie equivalents of what you guys are using for Injectors, Fuel Pumps and Coils.
      Now they ( BOSCH Agent) asked me if the EFI used ( That would be Tracy's) is of the type that varies the impedance of the Injectors - it had to be the very first question and I don't have a clue what the hell he's talking about so please help here!
      Another question is that Tracy favours the type of coils that is peculiar or different to other types of coils - could someone tell me what that is - in English so I get it right.
      TIA
      George ( down under)