Very interesting, always wondered about that. The critical cylinders in an inline 6 are cyls 1&6 since there is only 240deg. crank rotation from the previous cylinders (2&5). Since I am planning to run the inline6 with a GM ECU (same as 4.3L) I would need to place the O2s in the cyl.1 and cyl.4 exhaust stream.
There also seems to be some add ons you can put on mega squirt to turn it into semi-sequential like canems. I'm looking deeper into that because I already have a mega squirt I used on a v8. Canem asked about the chevy six firing order and port lay out but haven't told me if their controler would work yet. They are looking into it. I'll let you guys know what kind of replys I get.
Harry, After had trouble with the siamesed head and port fuel injection. I think the easiest fix is porting the siamesed opening larger and installing a divider. Got a new design in my own engine and am testing it. So far so good. The engine runs better than ever. Idle is clean and crisp response to throttle. Tom
Tom I may very well decide to take your route. I like the idea of being able to use the bigger port if the timed injections work as advertised but I also could get in way over my head with the electronics. I have been able to tune the mega squirt before so I would like to stick with that. I should just add some dividers and go with it. Do you feel I could still reach my 500hp. goal with the dividers? Just a little more screwing around before I make a decision. I seem to make it more difficult than it needs to be but my boat still floats and thats what counts. Thanks for the help.