Fuel injection systems

[Roger B]

The two cylinder engine ran better with the improved delivery valve so I had a look at the horizontal engine. There was a fuel leak past the delivery valve with only 0.8 bar from the fuel feed pump.

<a href="https://www.youtube.com/watch?v=QUn85ryqzMI" target="_blank">http://www.youtube.com/watch?v=QUn85ryqzMI</a>

I removed and dismantled the pump. There was a significant amount of rusty clag in the inlet port and delivery valve, probably due to the high moisture content of the cooking alcohol I used to use for trials. After lapping the delivery valve seat I cleaned it all in the ultrasonic bath and reassembled, replacing the delivery valve spring as there were signs of corrosion 

[Roger B]

Seems to run well  1000-4000 rpm

<a href="https://www.youtube.com/watch?v=2cAJzv1CCb0" target="_blank">http://www.youtube.com/watch?v=2cAJzv1CCb0</a>

[Kim]

Wow!  I'll say!  That runs GREAT, Roger!   

You have a daunting number of experiments, time, and effort into this!  What's your next step?  Are you satisfied?  Or is this still just one more step in your road toward perfection?

Kim

[90LX_Notch]

Outstanding.  Congratulations Roger, this has been such an impressive project.  It runs beautifully.

-Bob

[Admiral_dk]

So now you have two engines running great with your system      

I was almost thinking that you really had it all nailed until I realized that this is also running on petrol right now ....

Are all the rack bits for the diesel injector ?

[Roger B]

Thank you all for your support   

I don't think I can do much more with this version of this engine. The throttle response is excellent, I will also make some load trials to compare with the best carburettor version which may require a better radiator.

I am not yet happy with the twin. I think that the wedge stroke adjuster has too much mass/inertia for the speed range. The rack pieces are to make a smaller version of the helix control pump I am using on the diesel so I ca see if that will work better  The biggest problem may be that the injected volume is 1/4 the volume of the horizontal so the pump working stroke is around 0.15-0.2mm. I am looking at a 1.5mm bore pump but that changes every component on the way   

[Roger B]

I have stopped using this thread now due to the size. It continues here:

https://www.modelenginemaker.com/index.php/topic,10603.0.html