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Discussion Starter · #1 · (Edited)
OK, during my engine build for 2010 I needed to retain a stock Intake Manifold for class rules, so I ended up looking at alot of stock IM's used on various DURATEC engines and this is what I have learned.

First off, all of the DURATEC Manifolds for FWD vehicles are black plastic. Only the Ranger uses an aluminum manifold.

Second, there are two types intake manifold control systems used on the DURATEC Engine.

The "Tumble Flap" device is a simple butterfly valve located in the manifold runners within 1/2" of where it mates to the cylinder head. This is mainly an emissions device to improve combustion in the engine by creating a "tumble" motion in the intake airstream as the air enters the cylinders.

The "Runner Control" device is another butterfly valve buried deep in the center of the manifold. This is an engine performance tuning device that allows the ECM to switch between the long or short path through the manifold. The longer path is used at lower RPM's to enhance low end torque, the short path is used at higher RPM's to improve peak power.

Details:

I have personally handled 3 types of DURATEC Manifolds:
2005 D20 Focus
2004 D23 Focus
2006 D23 Escape

These 3 manifolds use a unique combination of the 2 control devices as follows:

The D20 Manifold only uses the Tumble Flaps
Both D23 manifolds use the Runner Control flap.
Only the D23 Focus Manifold uses both the Tumble Flaps and Runner Controls.

Pics:
D20, note how narrow it is in the middle. (no Runner Controls)


D20, this only has the Tumble Flaps, there is a single vac actuator and solenoid located under the TB.


D23, wider in the middle to make room for the Runner Controls


D23, may have only Runner Control or could have Tumble Flaps also.




These are shots of where the Tumble Flaps would be. The first pic is after existing Tumble Flaps were deleted, leaving the holes in the runner where the shaft would normally pass through.


This one is from a D23 Escape which was not mfg with tumble flaps so the runners have no holes in them.


Final techincal notes. Since I was doing lots of computer simulations for my engine build, I needed to get accurate runner dimensions/lengths.

This is what I came up with.

The ports are ovals and have a width of 1.9" and height of 1.3". This yields a CSA of just over 2 square inches. This appears to be the same for all 3 manifolds.

The D20 has a single intake runner path approx 14" long.

The D23 with the Runner Control flap has 2 paths through the manifold with the long path being approx 17" long, and the short path being approx 11" long.

All runner lengths were calculated from the parting face where the manifold meets the head to the point where the individual runner meets the common plenum chamber in the manifold, measured through the approximate center of the runner.
 
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un1corn
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It's like you were reading my mind! I'm glad you got
all this data and posted it! Someone with a cossie manifold needs to
measure the runner size and length.
 

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Discussion Starter · #4 ·
It's like you were reading my mind! I'm glad you got
all this data and posted it! Someone with a cossie manifold needs to
measure the runner size and length.
warneej has the Cossie IM, it's actually his donated stock take-off manifold that I have bolted on my race motor.

Anyway, I'm pretty sure the Cossie IM has very short runners, not more than 5-6" inches long.
 

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did i just get educated?? [:)]
i think i did... someone should send this to egz for the duratec wiki page..
 

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un1corn
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Yeah I had one but sold it this past winter. I should have measured them when I had it. The runners are very short and iirc appear to be "trumpet" shaped with velocity stacks. Still would be nice to have exact measurements though
 

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Based on the dimensions, what reasons would you chose one manifold over the other?
 
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Discussion Starter · #8 · (Edited)
Based on the dimensions, what reasons would you chose one manifold over the other?
I had to use the stock D23 manifold for the class rules, since it's technically an engine swap the manifold and TB from the donor engine was a required.

As it turns out, if I had a choice between the D20 and D23 manifolds, I would have picked the D23 anyway. Having the different runner lengths means I can get a bit more low end torque from the longer runner, and keep it pulling to about 7250 on the short runner before power starts to drop off significantly.

Since I don't have a racing close ratio gearset in the trans yet, having this extra flexibility in the torque/power bands is a big plus for road racing.

In my case, according to the simulation, having the 11" short runner gets my peak BHP close to 250. (we'll have to see what the dyno says) which is about 20BHP more than what I could hit on the 14" or 17" runners.
 

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It's like you were reading my mind! I'm glad you got
all this data and posted it! Someone with a cossie manifold needs to
measure the runner size and length.
I actually will be getting your IM this week i hope. just bought it from the guy that bought it off you. I will measure when i get it. Is there a sticky anywhere with all of the Cossie IM install anywhere. I would just like to read and study it for a few days
 

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un1corn
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Yeah, I think egz scanned it and put it on the dutatec wiki and I might have a PDF of it on my work computer, I'll check today. It might be a pita but an accurate measurement of plenum volume might be helpful to everyone as well.
 

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Fear the TurboSnail!
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So I'm wondering on a turbo application is the 2.3 would be better than the 2.0 on the 2.0L engine?
Posted via FF Mobile
 

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So I'm wondering on a turbo application is the 2.3 would be better than the 2.0 on the 2.0L engine?
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Would the 2.0 ECU be able to control the 2.3s runner controls, though?
 

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Discussion Starter · #13 ·
Would the 2.0 ECU be able to control the 2.3s runner controls, though?
I'm trying to work that out. I'm trying to use the functions to switch my tumble flaps to control the runner lengths. Since I have the SCT pro Racer package I can set the RPM/Throttle I want the change over to occur, and there are several tables/functions to modify fuel/spark etc when flaps are open/closed.

So since I really do not need to modify A/F ratios or spark for the runner length changes, I'll neutralize all the modifiers for "tumble flaps" open/closed, and set the Throttle/RPM where I want it.

My only concern is that there might be a few things in the cal that I cannot align to the new manifold, so I'll have to see how it behaves. Worse case scenario is I leave it on the short runners and give up some low end torque, or get an ECU from a D23.
 

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BodyKits=PantiesDrop
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If we need Cossie Manifold measurements I'm sure I could come up with some. Yes the runners are very short and have trumpet style velocity stacks on the ends. There is also a large rounded triangular (point down) plenum as the main chamber. We'll work some science and come up with some numbers..
 

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For what he is doing I wouldnt think he would want the runner controle and would remove them

The 2.3 out flows the 2.0 by a good bit when I had the 2.3 head on the flow bench. I never tested this with a 2.0 head because I would never use one

Tom
 

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I just unplug the selenoid for the runner control to leave it on short runners full time

Isn't the 2.0 and 2.3 head and cams the same, the only difference is the block on a 2.3l is taller by 1/2 inch.
 

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Discussion Starter · #19 ·
For what he is doing I wouldnt think he would want the runner controle and would remove them

The 2.3 out flows the 2.0 by a good bit when I had the 2.3 head on the flow bench. I never tested this with a 2.0 head because I would never use one

Tom
I just want the best of both worlds, with the standard gear ratios in the MTX75, I need as much low end torque as possible, so flipping from long to short runners @ about 5500 RPM works for me. If I run on the short runners only, I will probably loose about 15ftlbs TQ in near 3500-4000 RPM range, and about 7HP.

I think that's certainly worth keeping the runner control operational, the "tumble flaps" pictured above have been removed.....
 

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Awesome write-up. I was always curious about those those intake runners. The tumble flaps that you talk about for better combustion, for emmissions, Would that be for a little more torque on a street car? I see you can do that to a mustang motor, but I know thats a V/8 car. thanks again.
 
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