Bosch FI in Boats

Discussion in 'Gas Engines' started by thudpucker, Feb 5, 2014.

  1. thudpucker
    Joined: Jul 2007
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    thudpucker Senior Member

    My VW Rabbit had the Bosh FI and I liked it very well.;)
    Winter and summer it started good, except one winter at -20F for a week or so. Then I had to heat it up with the ReddyHeater.:mad:

    How does the Bosch work, seemingly without a Computer? Maybe a Computer was there and I didn't know what I was looking at.:confused:

    I think the Bosch could be used on a 4 Cyl Flat Head (American) engine. But I'd like to know some more about it.
    Hey.....:)
     
  2. BMcF
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    BMcF Senior Member

    The Bosch fuel injection systems have always had a computer or electronic controller..in the earliest versions (like my old '74 Volvo wagon) the "computer" was entirely analog and used contact points in the distributor to time the fuel injector pulses. In my old Volvo the controller was mounted under the passenger seat.

    I've adapted EFI to a number of older engines over the years (working on a '49 flathead V-8 EFI conversion right now) but I stay away from the older analog systems and use more modern control units that are digital and can be tuned/retuned to fit the application. There is a company called Howell that actually markets a retrofit kit that would propably suit your purposes but theirs are all throttle-body injection based, not multi-port.
     
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  3. Westfield 11
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    Westfield 11 Senior Member

    Megasquirt

    Which 4cyl gas flathead are you working on? Jeep?
     
  4. thudpucker
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    thudpucker Senior Member

    I had two Four-bangers in mind. One from a M-F tractor and one from a fork lift.
    I wa shoping to get away from Carb's entirely for better milage and smoother operations.
     
  5. CDK
    Joined: Aug 2007
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    CDK retired engineer

    They call it Engine Control Unit (ECU) and it really is a computer.
    If you can transplant the mechanical parts like injectors and sensors to a fork lift engine I see no reason why it should not work there. For good performance the memory chip that stores the injection map must be rewritten or replaced.
     
  6. thudpucker
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    thudpucker Senior Member

    Thanks all.
    I had one more engine in mind. The Mercruiser 140.:)
    But I can't go any farther with it this month.
    Thanks again.
     
  7. Westfield 11
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    Westfield 11 Senior Member

    The Merc 140 is OHV IIRC, not a flathead. Not sure, but I thought that the newest versions were EFI....? Regarding the two flatheads, a SBC might be lighter and would surely be cheaper to alter. Lots of parts out there for a small block, new or used and all cheap.
     
  8. thudpucker
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    thudpucker Senior Member

    All good points Westy.
    Thanks
     
  9. FishStretcher
    Joined: Oct 2011
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    FishStretcher Junior Member

    The early rabbits had Bosch CIS (K- Jetronic). I think the earliest had no oxygen sensor. It was essentially mechanical. The mass air flow sensor was a plate in a venturi that changed the metering of fuel to "injectors" in the ports. But they weren't solenoid injectors. They opened with pressure, that's it. Later units had more electronic refinement (K-jet with lambda, etc.), but the earliest may have had none. I bet E10 gasoline would be rough on the laser cut slits in the fuel metering valve.


    http://howautowork.com/list_of_contents/part_1/ch_1/SPARK_IGNITION_ENGINE_28.html
     

  10. thudpucker
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    thudpucker Senior Member

    Fish, thanks for that link. I'll read till my eyes hurt.
     
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