carbs to EFI, megasquirt?

You can use larger, single injectors in each runner of the intake manifold to deliver the fuel - with each injector supplying two cylinders - at least, that's what I'd always assumed

I wouldn't have thought it would be too hard,providing your engine management is up to the job.As long as you're getting the correct lambda reading at the end of it all,then fuelling should be good. Surely no real difference to single point injection?

that holden set up looks interesting.

I'm still a FI newbie though so cant quite tell how that works.

1 throttle body? How many injectors?

3 throttle bodies may be a great idea actually.

I'm my head i was basicaly thinking of 1 throttle body/plenum set up with 1 injector for each port.

If using 3 injectors would the need to be any bigger than if i was using 6? Wouldnt the injectors just fire twice?

Actually, i guess that depends on the cylinder cycle.

Ive not got very far into thinking this through yet


Would megasquirt be able to support 1 injector for 2 cylinders or would 2 injectors in each port be better?

Back to the 3 ITB idea, got any good links to how that kind of thing works in general?


Thanks.

In my mind (with a lack of FI knowledge) the whole thing doesnt seem too hard to sort out but i don't know if my mind is simplifying things due to a lack of knowledge or if FI really is as simple as i think LOL

This pic shows the complete set up, but also reminds me that Holden went from a 9 port to a 12 port head as part of the upgrade.



There are some more pics in the ad
cgi.ebay.com.au/VK-Commodore-6-Inlet-Manifold-Injectors-Throttle-Body-+_W0QQitemZ180434597484QQcmdZViewItemQQimsxZ20091120?IMSfp=TL091120164001r2653

www.megamanual.com/v22manual/minj.htm

have a read through this ;D make a cup of tea first though.

Martin (30psi) that is exactly what ive been thinking about. Just tried to find my parts book and manual so i could find the firing order and have a look at the cam to see what order the cylinders fill. Books must be in the car though so that will have to wait untill tomorrow. Theres no rush, if this happens it wont be for a few months yet.
If the siamesed cylinders don't fill at the same time then the injector would have to fire twice as often right? Rather than having to provide twice as much fuel.

I guess it would also help if i got my spare head out, maybe i could un-siamese the inlets?


Single point injection had crossed my mind but I'm not sure if it would be a great way to go with a 2.6 6c engine, especialy if i want to add forced induction at a later date.

Scary, thanks for the link. Saved to fave's, ill have a good read through that later.

Rich606, the vauxhall injectors sound interesting. 2 in 1 kind of affair. Ill look inot that further.

As for the holden set up, looks like thats out the window then. Would have been tricky anyway trying to source all the parts. I'd be far happier making my own manifolds and picking whatever TB i like.



Any more thoughts on 3 ITB's? I'm assuming if theres any thoughts of possible forced induction it would be far easier to go with a single TB.
If i scrap forced induction ideas though, 3 ITB's would be nice. Would it be easier, harder or no real difference to get that set up though? All that realy changes is each siamese pair has its own air supply, the fuel set up doesnt really change at all does it?

I wonder if there's any engines of about 0.8l that use single point injection, a 3 cylinder out of a Daewoo or Perodua or something. 3x0.8 is 2.4l, so a bit smaller than your engine, but I don't imagine the Zephyr engine revs particularly fast or has a particularly high volumetric efficiency. Three of them might flow enough air and fuel, if they can be separated from the inlet manifold and a manifold built to join them to the Zephyr engine.
Just thinking aloud but it's another potential place to start looking.

If there is a direct line of sight down the port to the back of the valve? With a bit of clever injector positioning you may well be able to just run it as if it was a normal 6 port set up, with the injectors firing directly at there assigned cylinders.

thanks, had a quick read and thats very interesting.

I had sort of assumed that all injection was sequential but obviously not.

I had assumed that FI was more efficent because of that.

As I say, mt FI knowledge is still in its infancy.

So if batch fired, as already mentioned, i'd just need to fire in twice as much fuel. The injection system has no idea how many cylinders there are or what the engine cycle is, it just chucks in fuel at a rate regulated by the systems sensors.

The more I find out the simpler it is