I need a 3L UIM explanation.......and some part buying advice

[Instigator]

I stop by the mechanic today to get a quote on bypassing my A/C compressor because the thing doesnt work and why the hell keep it on the belt anyway? but i was really interested in what i saw when i got there.......

before i go off track, i walked into his lot and up to his garage and i see a 98-99ish mercury sable wagon on the lift. Low and behold there is a 3L motor torn to pieces on the ground in front of it. I ask what year. He says 1999. I ask what happened. He shows me the block.....(the part i wanted to most) and theres this gaping hole in the side. Then he shows me the rod that went thru it:cry:

so no 3L block for me.....

anyways, theres the complete intake track, fuel rails, IMRC, Upper and lower manifolds separated from the block and heads.
they were putting a new 3L in the wagon when i got there.
so i ask dennis, if whatever you dont need can i have? he said what do you want.....i told him the upper manifold, the lower manifold, the IMRC, throttle body assembly....

should i ask for anything else? cuz hes just gonna give the stuff to me.:banana:

I want to do the 3L upper swap with my SVT Upper........will i notce a further gain over the SVT?

If so, what EXACTLY do i need for the swap? Ive been followingl the posts on this and its hard to put things together.....

So far i will have:
1.) 3L Upper Intake Manifold
2.) 3L Throttle Body, and Bracket.........do i need the throttle cable?
3.) 3L Lower intake manifold and IMRC..........will my injectors and fuel rail work? is it even worth to swap? are the ports bigger in the 3L LIM?

I read about customizing the IAC or the EGR perhaps? What do i need (or do) to make the swap work?

thanks for reading my long post and answering my Q's..........(if you did any of these):)

[jojolmnop]

no, the ports are smaller. i measured 30mm on mine. my svt lim sitting on the floor next to is measures 35mm. soooo... i gotta port it open more before install. give me time to buy the other parts needed.

anyways, you probably won't see many gains. from what i hear, your torque curve will be better due to the same size runners. other than that, only thing is just the work you'll need to do to route egr. nothing some copper tubing and welding won't fix. as for the lim, you might as well keep your svt one as it works well with the upper. same goes with the imrc.. you can keep that one just in case your current one dies tho.

another incentive for the conversion will the be the extra $300+ you can make selling your svt upper. hehe.

[mcon99]

Is the 3.0L upper better than the stock upper? YES

Is the 3.0L upper better than the SVT upper? Debatable. It's probably close, and the SVT upper might have an advantage at 5K+rpms due to the larger ports at supercharging effect built into the design. Still, being how much cheaper the 3.0L upper is, and how much easier it is to port, it is a great mod.

Don't need 3.0L LIM or injectors or fuel rail for upper swap. get the TB and bracket.

I'm not sure why you needed to see your mechanic about a non-a/c belt. As far as I know, all you would need to do is buy a non a/c spec'ed belt and install it, since it would take the same path minus the a/c pulley

[FastCougar]

I deleted my reply after consulting an engineer here at work ... I was wrong. If you didn't read my reply to Mcon99, you didn't miss anything other than I was completely off-base in my thought process.

[warmonger]

3L upper that much better than a stock upper? Some circumstances maybe, but mostly NO.

3L upper is a single runner design rather than dual runners. You are running a computer that is expecting a dual runner manifold with IMRC control and it plays with the fuel and timing curves BASED upon the expected manifold. Plus the cams are designed with it in mind.
The dual runner manifold uses short runners and long runners to maximize torque at low and high rpm. The 3L manifold will yield a nice large torque increase around 4000 rpm, but will fall short of the stock manifold at high rpm. This engine is designed with an ATX mated to it, NOT an MTX. There are no Fords using a 3L duratech MTX that I know of, at least not with that style manifold and pcm.
The ATX needs better midrange torque as the torque converter stall speed is also matched to it.

The runner diameters on the 2.5L are tuned based upon displacement, and the length upon expected rpm range.
Figure you can raise the diameter 10-20% to reduce drag on the airflow and still not decrease the velocity of the air too much. This is a trade-off of course, bigger runners equals better high volume flow (high RPM) but slower low-volume flow (low RPM) so you'll lose low-rpm torque.

What does this mean in terms of the 3L manifold?

Large single runner design means low velocities at lower rpm and means your take-off torque is going to suffer in a 2.5L...badly.
The high rpm breathing will potentially be better, but then you have the runner length to deal with. The length is tuned for mid-range, not high rpm, therefore reducing its high rpm breathing capability. It's a wash as far as the high end benefits.
So you get a nice torque spike in the mid-range for all your trouble.

Next, throw in the fact that the cams were designed for a dual runner intake with one cam lobe (primary side) best for the long runner and low rpm, and the other lobe (secondary) better for high.

If you take this information as being accurate as I do, then you'll quickly see that the trade-offs suck for JUST changing over a 2.5 upper to a 3.0 upper on a 2.5 engine. I still don't think its that great on an SVT 3L hybrid motor, but some people believe it is and I'm less likely to call them idiots because AT LEAST the 3L breaths more air and can use the manifold a little better.
Your best bet is to get an SVT manifold, or hand port out your own 2.5L upper and then send it to extrude hone for at least one-pass. It'll only cost you the $300-$400 dollars if heavy modification is in your future.

warmonger

[mcon99]

i'll admit you make a convincing arguement

however I'm sticking with my judgement until I see some dyno data to settle all of this for once and for all :)

[PuckPuck]

This engine is designed with an ATX mated to it, NOT an MTX. There are no Fords using a 3L duratech MTX that I know of, at least not with that style manifold and pcm.
Lincoln LS w/ 3.0L Duratec AND Manual Transmission (http://www.nctd.com/review-intro.cfm?ReviewID=667)

Many people have felt gains from the SE 2.5L manifold to the 3.0L Manifold... wether or not you get gains from the SVT to 3.0L or vice versa is debatable. However you defintely feel it with just the 3.0L manifold over the SE.

As far as optimal for the PCM, perhaps, but optimal for air flow, NEVER. We all know that bends in a manifold are horrible for air flow. This has been documented hundreds of times in numerous books and articles disucssing intake manifold designs. Some of the best manifold designs use a plenum sized slightly larger in size than CFM requirements per rotation, and equal lenght runners from the plenum. 2.5L UIM have none of this. I would even go to say the front most cylinders get far less air than the back cylinders because of the sharp bends and manifold design. The 2.5L manifolds have 4 SHARP 90* bends, while the 3.0L manifold has 1 sharp 90* bend and 1 gradual 90* bend. Yes porsched helped develop the 2.5L manifold, yes it's almost an engineering amazement, however i think it has more to do with packaging and noise than power output.

If you make the other necessary mods to open up the breathing on your car, and haven't yet upgraded to the SVT UIM, I would strongly consider the 3.0L UIM.

[Instigator]

so should i stick with my SVT and sell the 3.0 manifold?

or should i swap?

[Blackcoog]

Your choice. If you do some porting work on the 3.0L upper then switch to it. If not then stick with the SVT so you don't have to deal with all the fitment issues.

[HoosierContour]

My suggestion:
Sell your SVT UIM for $405 on ebay and buy an entire 3L long block for $400.
Use the 3L UIM or the entire engine, for more power.

[Jagular]

Hey, does that mechanic still have the 3.0L block? If so I want it. I don't care if its windowed. I will pay to ship it up here.

[Instigator]

sorry man, i went there to pick up the intake stuff yesterday to sell it on ebay, and none of it was there. My mechanic said the guy wanted all the old stuff incase something went bad on his new motor. I dont blame him, he blew the old one cuz he was too lazy to take care of it...

[warmonger]

Originally posted by: PuckPuck

This engine is designed with an ATX mated to it, NOT an MTX. There are no Fords using a 3L duratech MTX that I know of, at least not with that style manifold and pcm.
Lincoln LS w/ 3.0L Duratec AND Manual Transmission (http://www.nctd.com/review-intro.cfm?ReviewID=667)

Many people have felt gains from the SE 2.5L manifold to the 3.0L Manifold... wether or not you get gains from the SVT to 3.0L or vice versa is debatable. However you defintely feel it with just the 3.0L manifold over the SE.

As far as optimal for the PCM, perhaps, but optimal for air flow, NEVER. We all know that bends in a manifold are horrible for air flow. This has been documented hundreds of times in numerous books and articles disucssing intake manifold designs. Some of the best manifold designs use a plenum sized slightly larger in size than CFM requirements per rotation, and equal lenght runners from the plenum. 2.5L UIM have none of this. I would even go to say the front most cylinders get far less air than the back cylinders because of the sharp bends and manifold design. The 2.5L manifolds have 4 SHARP 90* bends, while the 3.0L manifold has 1 sharp 90* bend and 1 gradual 90* bend. Yes porsched helped develop the 2.5L manifold, yes it's almost an engineering amazement, however i think it has more to do with packaging and noise than power output.

If you make the other necessary mods to open up the breathing on your car, and haven't yet upgraded to the SVT UIM, I would strongly consider the 3.0L UIM.


Puck, you know I wrote there is no 3L MTX "Ford" car. I also stated "at least not with that style manifold and pcm"! The LS is a rear wheel drive Lincoln and it has different heads, cams, direct acting buckets on th valves and different intake.
Not a fair comparison.
As I stated, the Taurus/Sable/Escape motors are all 3L's designed for ATX's and would be sort of a compromise with the MTX.
Also, a bend is a bend is a bend. If you have even one bend then you slow your intake velocity down to the speed that it can handle, the other bends make little additional difference. The velocity doesn't just speed up again because it is going straight. It can only speed up again if the passage becomes smaller, increasing velocity but decreasing flow throughput. Besides, the air doesn't instantly change speed from one bend to the next. The manifold flows at a relative steady-state and any "one instant" that you look at it. All velocity changes are gradual and based upon RPM changes more or less.
Basically, if you size the piping right, then bends aren't going to reduce power. The longer runners are better for certain torque ranges, period, bends or no bends.
The 3L manifold gives a bump in torque in the midrange at the expense of the low and the high, nothing more. The BUTT dyno says more because its higher in that one area than it was anywhere else before. If thats what you're looking for then go for it, but there are many ways to define success.
My method for success is a broad flat torque curve and more area under the HP curve. The 3L manifold can't match the port matched dual honed upper SVT IM combined with dual honed and portmatched lower IM for its broad power curve.
Just look at my dyno results to see what I mean.

Check my website if you want to see the broad power capability of this combo on a basic low compression 3L hybrid. Compare to any dyno of a 3L upper and see what you get. Just bear in mind that this dyno on my page was without the msds headers, my low end torque on my engine bumped up 7-11 ft-lbs in some areas just from the headers when I put them on, equaling the height of the second torque hump.

My homepage (http://home.earthlink.net/~twilson2800/index.htm)

[Blackcoog]

What compression are you running right now with the turbo warmonger? How did you lower it if you did?

[warmonger]

I hand machined the combustion chambers so that they were similar to the 3L chambers, then I put in the 3L valves too. I did it almost 2 full years ago, back in Sept-Oct of 2001. The heads have been perfect so far. I cc'd the heads before I installed them and I came up with a static compression ratio of about 10.2-10.3:1 I am currently running the same motor with the addition of the turbo and I'm making about 300+ wHP and 265 wTQ. That is up by about 90 wHP and 85-90 wTQ with just the basic 3L engine I had.

warmonger