6 replies to this topic

[milkandoj]

The stock 450cc vr4 injectors, blue top with the BLACK bottom, are they a wide angle spray pattern, or a narrow pencil spray?

Being a 2 valve intake i'd assume id need injectors with a wide angle spray or that directs it two ways into each valve (like the later evo injectors)

The later injectors with the figure 8 cut out in the pintle cap, i "assume" angle the spray in two directions to each valve. Is this correct? (Evo 1-3, 510's... Evo 4-8 560's... Rvr 450's.)

I'm deciding on what spray pattern to go when getting new injectors.
If stock vr4 450's are a narrow cone the intake would be adapted to suite the contact of the narrow bean of fuel and be a different shape to later evo motors. So i would stick with that.
If they are a wide cone i can stick with that, or an injector that fires it to two sides. So there is minimal pooling with the walls of the intake ports.

In my searches i found some pics that show what i'm asking. Related to other twin valve motors.

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Edited by milkandoj, 31 August 2010 - 12:39 PM.

[D3bb4]

for best atomisation, fuel needs to either be sprayed onto a surface, or in the centre of the highest velocity air. I'd assume would be fine to spray into centre of the port divider based on that... but yeah, spraying onto the back of the valve is good; but again - it's a surface. Might go re-read some books on this now...

[Evo-00x]

GVR4 450cc injectors (blue tops) are a single spray nozzle design.



However, RVR turbo/DSM turbo 450cc black top injectors have a twin spray pattern like the yellow top Evo injectors (I have a set of 450cc RVR turbo black top injectors Im selling for $100 set if anyone is interested - they look the same as the injectors pictured below)

Edited by EVO-00X, 31 August 2010 - 02:22 PM.

[milkandoj]

Im aware that vr4 injectors are single spray. And i know the evo, and rvr ones look the same, i was asking about the actual shape of the spray they give. Ive got them all except rvr ones in the garage haha. Thanks for the pics anyway.

What i'm trying to figure out is are they a narrow pencil beam that hits the divider. Or a wider beam. So i know what the shape of the intake was built to use. If i could find the spray angle that would pretty much be all i need to make my mind up.

Single valve engines often run a narrow beam so the fuel hits the center of the hot valve and vaporizes that way and the extra interta behind the narrow jet gets it there without being blown back onto the walls of the inlet.
Most multi valve engines have injectors that are the single pintle with the twin diffuser cap like the evo and rvr injectors or have have a pintle or disk with a cap with multiple holes to atomize the spray better and often split it in two directions. Too wide a beam and it hits the walls.

The stock 450cc vr4 injectors, blue top with the BLACK bottom, are they a wide angle spray pattern, or a narrow pencil spray?

The later injectors with the figure 8 cut out in the pintle cap, i "assume" angle the spray in two directions to each valve. Is this correct? (Evo 1-3, 510's... Evo 4-8 560's... Rvr 450's.)

Edited by milkandoj, 31 August 2010 - 04:03 PM.

[to4garret]

Good luck finding that info.

May need to make a test rig using a spare fuel pump, rail, Fpr and exciting the injector with some D cell batteries.

[BMGTZ]

Good luck finding that info.

May need to make a test rig using a spare fuel pump, rail, Fpr and exciting the injector with some D cell batteries.

or take one too an injector cleaning place and ask to see it in action.....maybe even compare it to and evo injector. i think i have one of each you can borrow for this purpose if you want to go down this path

[Evo-00x]

Ah sorry, I missed the question.
The stock GVR4 single spray injectors have a narrow pattern and you'll end up with more fuel hitting the walls, pooling and making it harder to get the A/F ratios right for tuning at high rpm.
The twin spray injectors was the revised design Mitsubishi obviously upgraded to for the latter 4G63T 16v heads. The twin spray design split the fuel spray pattern into each port better (before the valves) and they provided better tuning capability.
Basically, the better the efficiency of the atomisation of the fuel in the centre of the port the better it distributes through the split. Multiple (finer mist) > twin > single spray.
Still, even with different spray patterns if you dont choose the correct injector size/spray pattern/efficiency range to suit your needs they can make tuning much more difficult that it needs to be.
I remember looking back into it a while back when shopping for big injectors and I eventually went with Precision Turbo injectors with a 6 spray tip - they're pretty popular with the DSM's (see pic below).
Im sure there's gotta be videos around easily showing you the diference between single vs twin vs fine spray patterns in multivalve heads.

Edited by EVO-00X, 01 September 2010 - 12:54 AM.