4 runner intake for 6 cylinders?

[jakobsladderz]

If you can somehow design your manifold to mate up with the division b/w the 1+2 and 5+6 runners, such that you end up with (nominally) 6 intake runners, that would work best with port injection, although you'd probably get away with an injector pointing into each valve, at the expense of some mix variation. I wouldn't try the shared arrangement if the valve timing is not 360 crank ° opposed though, as there will definately be fuel distribution issues. for TBI it probably doesn't matter as much. I believe some of the mini people (as opposed to small people) have a similar issue as some of the older engines have 3 ports, with the middle 2 siamesed into one..

[Jim]

If I were you I would NOT attempt to create a new manifold or install
individual injectors for several reasons :

1) You would completely lose the original "look" of the engine .

2) You will definately have problems with Mixture Distribution .

3) You will lose your intake heating , without that heating one or
the other of the 2 ports in the front or rear inlets will very
likely hog most of the fuel because it's still in wet droplet form
and hasn't been fully vaporized by being heated .

4) Single barrel Throttle Body Injection units are all over the place
in any junkyard , (check out GM 4 cylinders) this would probably
allow you to keep the original Air Cleaner as well as prevent
mixture distribution problems and it could probably be made to
bolt-on with a simple to make aluminum spacer .

5) No Custom Fuel Rail to build .

6) No problems with selecting expensive injectors .

7) No machining of a manifold that might be imposible to replace .

8- You have to have a Throttle Body anyway you do it ,
why not get one with an injector built-in ?

9) This engine will never make alot of power , going crazy
modifying the intake is not going to make it smoke the tires off .

10) GM TBI units run on much lower pressure (13 psi) which is
safer and cheaper than "Port" injectors (45 to 75 psi)

11) Simpler wiring , if you find a donor car with the TBI harness
in good shape you would save many hours of work and have a
factory look to boot .

[Matt Cramer]

It looks like you could modify the front and back runners by putting a divider in them, thereby "un-Siamesing" the ports.

The other possible solution that I can think of would require a custom cam (or reverse cam drive) and fabricated manifolds, but is workable and was done on a fair number of flathead Ford V8's: Reverse the ports. Use the intake for the exhaust and the exhaust, which has six beautifully separate ports, for the intake.