All, I think people may find this interesting. I am interested in fuel injecting a Packard straight 8 engine, which has Siamese intake ports as many old engines do. The conventional wisdom is that these type of engines can't get sequential port fuel injection, due to the 2nd cylinder robbing fuel from the 1st cylinder, as discussed many times here. I was doing research on this issue. I have found that a group interested in the British Classic Mini from the 60's that was produced there for many decades, actually up to the year 2000 had a 5 port, 4 cylinder engine (Austin A-series) figured out how to make sequential port fuel injection work on a Siamese port engine.
Basically what they are doing is programming an EFI system to think the engine is twice the displacement it actually is and only using the injectors for the 1st cylinder of each Siamese port pair. The injectors are timed to middle versus start or end of spray time, so that the middle of the injector spray is when the 1st cylinder's intake valve closes of the pair.
It takes more time to get tuned, since the injector timing needs to be precise so half of the fuel load goes in each cylinder. A wideband O2 in each cylinder of 1 Siamese port cylinder pair is required to tune the engine. For a 4 or 8 cylinder engine injectors need to be sized for a duty cycle of only 20-25%. So the 1st cylinder doesn't go lean. For you 6 cylinder guys, the degree of separation on the Siamese port is greater so 27-33% duty cycle sized injectors will work for you.
A Megasquirt 3/Extra will do this, but it only supports 2 additional staged injectors in a wet manifold setup, which you may need based on your HP goals. If you have a 4 cylinder engine you can use a Megasquirt 2/Extra with the special Siamese Code, which allows for staged sequential port fuel injection. So for the 6 cylinder guys you could run two efi setups, 1 for the outer 4 cylinders and 1 for the inner 2 cylinders if you have to have staged sequential injection.
I am not running yet so I can't give you real world info on this. I just thought people would want to know. The turbominis.co.uk forum has good information and helpful people if you are wanting to pursue this.
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=612576Best Regards,
John R.
