I finally got my heads back from the shop that did the port-matching to my SVT LIM, and I'm a bit concerned with the new injector "dimple" that they made. It looks too shallow to provide a good spray pattern, like it might deflect some of the injector spray and/or puddle the fuel. The shop said they didn't want to make it deeper because they were afraid to compromise the strength of the walls by making them too thin, and they said it would be ok that way anyways. Did you guys have to add any aluminum to the outside of the heads? Please check out the links to my pics below and tell me what you think. I should be able to get more pics of the heads with the LIM and injectors sitting on it tonight. I would especially like to hear from DemonSVT, Blackcoog, Warmonger and anyone else who has first-hand experience about this. T.I.A.!
Pics:
Pic 1 Pic 2 Pic 3 Pic 4
Hey, i am a newbie, but u should know i just finished my 3litre project and to tell u the truth, thats all my injector ports looked like, and it ran great, the only thing is, Due you plan on gasket matching? Because if you planed on using the factory gaskets theres not enough materiel where they filled the old injector ports to seal properly, it should protrude farther than that.
One thing you guys may want to consider doing......
I cut my new injector ports to spray into both valves rather than just one. I also cut back on the center divider a bit to enhance that idea.
why would you have your spray pattern aimed at both valves? What's the advantage?
The 3L's are aimed at both valves being in the center of that oval port. In that case the air and fuel would be mixed more evenly when entering the combustion chamber. I always try to angle mine at both valves.
I'd say the porting above is a bit shallow but if the gaskets match up you should be ok. I normally add aluminum to the top and bottom of the oval port and it doesn't look like they added any opposite to the original injector spot, but most on here don't do that anyway. Make sure your gasket seals correctly. It might be really close but you should be ok if it does.
...on a 3.0.Owners may want to take a look at the
nozzle hole position on an oval port injector Vs a
'split port' injector.Oval port 3.0 injectors have the
nozzle head clocked so the holes are always in the
same position...split port holes are random...which
poses the question ,if using a 'modded' oval port but
with the injector moved to the 'split port' position
should you 1)retain the oval port injector or 2)find
an injector to match the lbs' of a 3.0 oval port BUT
with the random spray pattern of a split port.Why does
the oval port injector have clocked holes on the
nozzle?....so that two of the 4 nozzle holes go in
each of the valve areas and not the 'center' portion
of the oval port....spray pattern and angle is very
important....
.....think,.....where do you guess the injector spray
should be on an oval port injector that feeds two
areas that have say a dimension of 55 MM port wall to
port wall fed by one injector in the middle Vs the
spray of an injector designed to spray on a smaller 30
MM port wall?...Think about the angle of the 4 sprays
on those injectors,where do you think they should fall
in relationship to the port...be it small & round or
oval and wide?....think about divergent spray angles
and why you want they spray in a specific area of the
port....think....Where is the injector sparaying in
YOUR port set up ?????
Thank You!
This is exactly why I modeled my injector port after the stock setup ... because I'm using the stock injectors.
Might I suggest a scenario if you will: "aiming" the injector from the far left to try and inject into the far right will only result in slamming the fuel into the dividing wall. This will cause "some" fuel to get to the right port, "some" will be caught by the intake stream of air and pulled into the left port, but "some" will be slammed into the dividing wall and will because unsuspended (de-atomized). Proportions don't matter here ... assign "some" whatever value you want ... the fact remains that it's not ideal for atomization. Also consider the "turbulance" that is created from a split port UIM design dumping into an "expansion chamber" with a "shared" area between two seperated chambers. You will get some cross flow for sure, but I suspect that the majority of air will keep it's initial direction with a lot of boundary turbulance. Someone correct me if I am wrong in my assumptions.
....you have oval port heads with the injector in the
twin port position....the oval ports have had the
center section of the port ground away....ontop of the
intake ports/head you bolt a conventional twin port
LIM with the secodaries retained....what is the
air/fuel flow into the ports like with a closed
secodary...?...Picture this with a stoc twin port
injector with a narrow nozzle spray angle then picture
it with a wide angle 3.0 oval port injector......
...think about the velocity of the air coming thro
that single open LIM being split and fed to two open
valves via the oval port?....its direction ,velocity
and it's ability to atomise fuel from the offset
injector with unequal length spray paths?.....
I think that TH and I are on the same page here. I cut mine to aim directly at the back of the valve ... just like the stock setup because I'm retaining the use of the stock injectors. I guess the better question here is who is aiming at the center and using the stock injectors? If you are, you may not be helping at all and may be hurting your fueling atomization. Now, if you have and you are using the oval port injectors, you are accomplishing what you thought you would when you cut the heads. The key variable here and what Terry is pointing out is that the injector spray pattern is different in the two heads and most people that use the oval port heads and retain the split port injector location reuse their split port injectors.
Originally posted by fastcougar:
I think that TH and I are on the same page here. I cut mine to aim directly at the back of the valve ... just like the stock setup because I'm retaining the use of the stock injectors. I guess the better question here is who is aiming at the center and using the stock injectors? If you are, you may not be helping at all and may be hurting your fueling atomization. Now, if you have and you are using the oval port injectors, you are accomplishing what you thought you would when you cut the heads. The key variable here and what Terry is pointing out is that the injector spray pattern is different in the two heads and most people that use the oval port heads and retain the split port injector location reuse their split port injectors.
Naaa, The real question is: Who the hell has gone through the trouble to change the injector mounting boss angle in the LIM (not the head) and fuel rail feed nozzle angle enough to allow the injector to be "AIMED" anywhere at all?
None, nada, no one who's gone public anyways. 
So who the heck cares? THe purpose of widening out the valley/channel where the injector spray comes out into the head is to give it the best shot possible for fuel to hit the second valve inlet, irregardless of any other issues. If there's metal in the way then the chance of getting fuel to the second valve is low. So use what you've got and hope you get enough over there. If you don't, no worries because it won't be acting any worse than the stock split port system does, which is pretty darn good anyways right????
exactly what tom said....
you can't "aim" the injector...it's gonna spray the same unless you modify the LIM. I just slightly cut mine to right hoping that when my 2ndaries open up...that extra cut will help the air pull a little more fuel to the right.
But I don't think anyone has aimed any injectors anywhere
Thanks for clarifying that Tom ... that is exactly what I was thinking but forgot to mention. When I said "aim", I meant the angeling of the channel, not the injector. It's a given seeing as how the injector is aimed based on it's fixture in the LIM. It would take more than just recutting the LIM, you would have to actually modify the fuel rail as well since the top "cap" has very little deflection or "wiggle" room to "point" the injector face.
So basically what you're saying is that I should be fine, especially if I just grinded the injector lanes on the heads out a tad more?
You do have room for it.
In it's currant form, it may just disperse the spray pattern a bit more by hitting such a ramp which may help atomisation, and since the A/F mixture is more or less drawn in once the valves open it might not be a bad thing.
Just a theory anyway. It isn't what I did, but it sounds like it could be an option to me.
I would think that the opposite would be true. Liquid particles that are forced to share the same place normally congile into larger particles ... they "pool" together. Like TH said, it would depend mostly on the velocity of the air in which the particles are being injected. This was my theory and why I made my injector valley as deep and spread out as I could. Mine started out deep and shallow and then bleeds out and expands as it meets the floor of the chamber behind the valve.
.....oval port with offset injector is a compromised
system.It's neither a good spray angle for a twin port
as you are now spraying into an oval in an offset
position and not good for an oval as you still have a
secondary,closed,above the second valve with a 'snake'
airflow and lowered velocity.Only a custom injector
with a clocked nozzle head and modded spray angles,2
for the the 'open' lim and 2 to try to traverse the
added distance from the injector across the port to
the second valve may help the poor spray pattern to
the second valve or a two injector system per
cylinder.....the airfow thru one port of the lim is
off when secondaries are closed and the injector spray
position is off when the secodary is open....neither
is good for fuel mixing .The stoc twin port system
injects air fuel to one port all the time,when the
secondary opens all that does is add more air to water
down the over rich mix in the injector port....that
'final' mix happens in the cylinder .The best place to
get this mix right would be in the port,as a stoc
central injector 3.0 does with an oval port.....might
as well weld in a wall to an oval port and call it quits......
OK, this thread has bugged me for a bit now and I have to put in my final word. Take it for what it's worth.
There is much more to porting and mod'ing these heads to do well. Relocating the port injector is simply ONE step in a multi-step process. Relocating the injector port is one of the EASIEST mods to these heads one has to make to put some serious power down with them. There's a ton of other things you have to do to get these to work well! The total amount of time I put into my heads, the injector ports had a tiny fraction of it. Attention is needed elsewhere to pull these multiple modifications off. Look at my dyno proof with a craptastic break in tune for proof, if you need to.
When one is able to produce power in NA or FI form that is simply wicked for this platform to even handle, why would you go to the trouble to retain the center injection port!? If it's that optimal, than go ahead and make a custom LIM and fuel rail to retain it and keep the Aluminum UIM's, or show me an engine in a Contique that has retained the POS plastic UIM/LIM that has made some power worthy of mentioning past a daily driver amount.
As "compromised" as my system is, I'm doing really f$*%ing well
I ususally don't say this but this puppet posting by TH is getting a bit annoying. If he want's to post here than he should re-join our community.
Every setup is a bit of a compromise unless you have the big $$ to tool up your own castings to you exacting specifications etc. I know my setup isn't 100% perfect but it works well enough for a streetable NA setup. There are certian things I would change if I had the $$ to do so but the gains I would likely see in return would be far less than the total dollars spent to achieve that ultimate number. Also everyone who does this has their own idea of what the ideal setup for them is. For me it was retaining the stock look of the 2.5L engine but also gaining the additional oil drainbacks which should help the longevity of my engine (espically considering the hard track abuse my car will continue to enudure). One thing that I find interesting is that dollar for dollar these poor offset injector locations (as TH claims they are) on the modified oval port heads have for the most part made more HP or at minimum the same HP as ported split port "hybrid" 3L's for less money. Bottom line is everyone makes thier choice of what they want to do for thier build and it is up to them to make the most educated decision as to what the best options are for themselves.
