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Secondaries in LIM make no sense...

Brokendown

CEG'er
Joined
Aug 11, 2009
Messages
326
Location
Farmington Hills, MI and Big Rapids, MI
I have been doing a ton of research into this as I am wanting to my 3L right. I was thinking about doing a port matched swap because I want to use my SVT UIM. As I was sitting in my Airflow Analysis class I started thinking about this stuff...The reason the secondaries work on the 2.5 heads is because there are two separate ports all the way through the cylinder heads. But in a portmatched 3L head, there is one port for both the open runner and the secondary runner.

So in reality, keeping your secondaries is pointless because the air will just go around them and actually terribly screw up the swirl effect the engineer designed the 3L cylinder head to create. But gutting the LIM will also reduce power because the air slows down so much.

I guess my point and question, which I am sure people have discussed and if the lack of a tune is the issue I understand. But why don't people just use the 3L LIM and then port match those for the SVT UIM? Theoretically, the 3L UIM would be better use, but people want to use the SVT UIM for looks and ease and all that stuff. I want to use the SVT UIM because personally I think it will flow better than the 3L UIM, as far as N/A is concerned. But I will be doing tests on the flow bench to find out which one would be ideal. Plus using the 3L LIM would allow the use of the 24# injectors that come on the 04+ models which would be a nice addition with a 65mm Mustang TB...

Also, I am not saying I am right, hence why I am posting this and wanting your feedback. Please don't be offended or attack me for what I say. I am man enough to admit when I am wrong.:laugh:
 
because the SVT UIM is split port and the 3L lim is oval port. the split port is physically larger then the oval port. I don't think you can adapt the split port to the oval port like is done with the 3l heads to match the split port UIM.

now you can use the NPG LIM which creates a transition from the split port to the oval port so it all just bolts together. And you can use the 3L injectors since they are located in the same orientation as the 3L lim.

also you should match injectors to the lim that you are using. the spray patterns are different depending on split or oval port.

now don't forget that the secondaries create two hp and torque peaks, one in the low rpm range and one in the upper rpm range.
 
The original intent of the staged intake manifold is to keep air velocity high during low engine speeds to promote cylinder filling and aid fuel economy while allowing for much higher air volume at higher engine speeds.

I will agree that when you match an oval port head with a split port intake, it is no longer ideal. I believe, however, that it still provides most of the low engine speed benefit, just not optimal.

At high engine speed, when both primary and secondary are feeding the oval port, it doesn't matter as long as the ports are reasonably matched. I mean that the oval port doesn't care if there are two sources as long as it gets what it needs.

Oval ports as we see them on this engine don't do much for fuel economy or low speed power. At least that is my opinion from owning and driving both a Contour SVT and an 03 Escape. I know the Escape is heavier and has a bigger engine, but the fuel penalty is more than it should be. I'm sure that has a lot to do with the need Ford felt with redesigning the heads and ports on the newest Escapes.

If you are after absolute highest HP at high engine speeds, ditch the secondaries. If you intend the car to be a daily driver with some sort of semblance of reasonable fuel economy, keep them.

At least that's the way I see it.
 
That makes sense. I am looking for power in the higher RPM ranges because I am hoping to autocross it but at the same time I am going to be daily driving it more so it is a toss up for me. The other thing I like though is the 24# injectors the 3L has. Matched with a bigger TB and ported and polished heads and manifolds and a better fuel pump, that would be ideal. But sticking with 19# injectors and doing all this, to me, would be a waist because they would have trouble supplying the fuel and get burned out too quickly.

I do very much appreciate the feedback by the way.
 
to my knowledge no one has had an issue running 19# injectors in a 3L. and I know of a 3L hybrid that has close to 60k on it and its untuned and runs the stock 19# injectors.
 
That makes sense. I am looking for power in the higher RPM ranges because I am hoping to autocross it but at the same time I am going to be daily driving it more so it is a toss up for me. The other thing I like though is the 24# injectors the 3L has. Matched with a bigger TB and ported and polished heads and manifolds and a better fuel pump, that would be ideal. But sticking with 19# injectors and doing all this, to me, would be a waist because they would have trouble supplying the fuel and get burned out too quickly.

I do very much appreciate the feedback by the way.

Your pump and injectors won't need to be changed until you go FI. Stick with the stock pump and the 19's.
 
You should stick with the 19s only I'd you Re using the svt heads an cams. Cause that's whY they flow an are designed for a split port. They have a smaller spray pattern where's the oval port uses a wider spray pattern
 
Thanks for all the good info... If you guys are saying just stick with 19# injectors then that's probably what I will do considering you guys have been around the block with this stuff. I will still think about it but I really appreciate the information.
 
That makes sense. I am looking for power in the higher RPM ranges because I am hoping to autocross it but at the same time I am going to be daily driving it more so it is a toss up for me. The other thing I like though is the 24# injectors the 3L has. Matched with a bigger TB and ported and polished heads and manifolds and a better fuel pump, that would be ideal. But sticking with 19# injectors and doing all this, to me, would be a waist because they would have trouble supplying the fuel and get burned out too quickly.

I do very much appreciate the feedback by the way.

Unless you're doing Auto-x with 110 mile sweepers you will be better served by a more robust power curve (3 liter). You will also enjoy the daily drive-ability of the 3 liter manifolds.

Port matched swaps are so antiquated and hodge podge I can't believe people still do them. Then again there are quite a few retards in the world.
 
Are you calling me a retard? Listen douche, all I ever read in my research is you talking about how awesome full 3L swaps are, but you don't get it. Many people have had both and many people like different parts about both. The fact that you call people "lazy" because they want to use SVT manifolds because they are easier to hook up and they think they look better just shows how much of a tool you are. As it turns out, the higher range of the power matched with a 4.06 final drive would be a better idea for autocrossing...it will create a lot more zip and the very few times I am below 4000 rpm, the 4.06 gears will make up for that. I am not saying a full 3L is bad but I am sick of you talking about how stupid port matched swaps are when in reality it makes a lot more sense for a lot of people over a oval port swap. Maybe for a turbo the bigger oval port setup would be better but for N/A the port matched design will create more velocity. And I saw last night talking about how much more CFM the oval ports flow. If you knew anything about air flow, more CFM doesn't always mean that's better for the engine. There are so many factors involved you have to look at the whole picture.
 
Are you calling me a retard? Listen douche, all I ever read in my research is you talking about how awesome full 3L swaps are, but you don't get it. Many people have had both and many people like different parts about both. The fact that you call people "lazy" because they want to use SVT manifolds because they are easier to hook up and they think they look better just shows how much of a tool you are. As it turns out, the higher range of the power matched with a 4.06 final drive would be a better idea for autocrossing...it will create a lot more zip and the very few times I am below 4000 rpm, the 4.06 gears will make up for that. I am not saying a full 3L is bad but I am sick of you talking about how stupid port matched swaps are when in reality it makes a lot more sense for a lot of people over a oval port swap. Maybe for a turbo the bigger oval port setup would be better but for N/A the port matched design will create more velocity. And I saw last night talking about how much more CFM the oval ports flow. If you knew anything about air flow, more CFM doesn't always mean that's better for the engine. There are so many factors involved you have to look at the whole picture.

Ummm straight 3l is way more easy than hogging out the head or even spending more money for the swap parts it take to use the svt intake. Last time I checked people autocrossing want lowerend power cause most tracks are short straight aways. That's why there isn't alot of turbo cars autocrossing cause they don't make the lowend power of a na. Not saying there isn't any turbo cars. Just most are na
 
Unless you're doing Auto-x with 110 mile sweepers you will be better served by a more robust power curve (3 liter). You will also enjoy the daily drive-ability of the 3 liter manifolds.

Port matched swaps are so antiquated and hodge podge I can't believe people still do them. Then again there are quite a few retards in the world.

Are you calling me a retard? Listen douche, all I ever read in my research is you talking about how awesome full 3L swaps are, but you don't get it. Many people have had both and many people like different parts about both. The fact that you call people "lazy" because they want to use SVT manifolds because they are easier to hook up and they think they look better just shows how much of a tool you are. As it turns out, the higher range of the power matched with a 4.06 final drive would be a better idea for autocrossing...it will create a lot more zip and the very few times I am below 4000 rpm, the 4.06 gears will make up for that. I am not saying a full 3L is bad but I am sick of you talking about how stupid port matched swaps are when in reality it makes a lot more sense for a lot of people over a oval port swap. Maybe for a turbo the bigger oval port setup would be better but for N/A the port matched design will create more velocity. And I saw last night talking about how much more CFM the oval ports flow. If you knew anything about air flow, more CFM doesn't always mean that's better for the engine. There are so many factors involved you have to look at the whole picture.

:laugh: brokendown, meet pudmunkie. pud, brokendown. lol. dont let him get to u bro. thats pud for ya. i'll give him this much... he's always looking for sumthn better. when splitports were the talk of the town(ceg), he was on that bandwagon as well. quite faithful to it i might add. now he's seen the "light":laugh:
 
My bad...Sorry Pudmunkey, I shouldn't have gone off like that. But going back to what Contour2gq said, yes you do want some low end power but when I autocross, I am almost NEVER below 4,000 rpms. But for the very few times I do, the 4.06 gearing will give enough push to make up for the lesser power down below. I'd rather have an engine that can rev out to 7000 rpms versus one that falls flat on its face at like 5725 (I think I read that somewhere). And yes, turbo cars generally don't make good cars because of the turbo lag. But don't confuse having higher turbo horsepower and higher N/A power. With a turbo car, even when you downshift and your engine shoots into the high rpms, the engine will still take a half a second to build that boost back up.

And as far as easiest swap goes, they both have their difficulties, but port matched, TO ME, would be easier because then I don't have to coon rig an EGR (I want mine, despite what people think, it improves gas mileage and when under power, it doesn't seem to effect performance), mess with all my vacuum lines, get some custom intake, HAVE to get a tune, all that stuff. Where port matched, really all you have to worry about is grinding out those ports. And I don't need bugzuki plates because I can just take a gasket, scribe it on the head, port it out that way and fill the injector valley with weld and then grind that down.

To me right now, a port matched swap would be the best option for me, I am just trying to look out for future mods down the road. So yeah, back to my question, does anyone make bigger after market injectors besides the NPG 42# injectors?
 
That makes sense. So then would regular Mustang 24# injectors work on my SVT LIM and UIM. I am wanting bigger injectors because I am hopefully going bigger on all my intake stuff so I will need to go bigger on my fuel stuff.

not exactly positive. i'll research that and find out. how bigger exactly r u going on ur intakes? That wouldnt necessarily require the use of bigger injectors, i dont think.
 
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