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Discussion Starter #1
What do you think about my new inlet manifold design? It has 72mm (2.5") Inlet. fits to 159 1.9Lt JTDM engine. But I have a problem with the flow. I want to give some information.

For Flow Test in Solidworks
I gave input : 161000mm/sec flow speed at 4 bars and 75C temperature. It is equivalent of 1.9lt x 4Bars @5200rpm flows in 72mm pipe.
I gave outputs to envirenment 1 Bar @20C.

But I dont like the result. I have a better idea but It is pain to fit the manifold because of the Fuel Pump. I saw many manifold designs for TDI engines and they are not perfect also. What do you think about it? can you give me hint please?
 

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Discussion Starter #3
For research purposes off course. We cancelled flaps, egr, egr cooler, flaps motor etc. And I want to make 2.5" all the way from turbo to manifold. Also I've changed the 16 valve angles, and ported the head. So original manifold is not ok to use. If It will give me 5HP 15Nm it is ok to me. Bu It is me hobby so, here it is.
 

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do you have room to make the plenum bigger around the 4th cilinder, and/or extend the plenum chamber a bit beyond the intake runner.

Alos, add a piece of the intake tubing to the modelling, instead of increasing the neck.
 

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I admire your enthusiasm. But I think you are traveling into a dead end there.

Those simulations are next to useless... sure, pictures are nice, but this is far away from reality.

First, airflow is not constant, its pulsating, even at manifold entry. But much more so at intake runners. Each pulse ~180° of crank rotation.
It is true that manifold acts as some kind of buffer that evens out the pulsation, but it is still not constant airflow at the manifold entry.

Second, only one cylinder sucks air from the manifold at certain point in time. There is almost no overlap on 4cyl engine.

Third, firing order is important.

Because of the above airflow patterns are completely different.

What you should do is something into this direction:

https://www.youtube.com/watch?v=X3ecq8MNfk0

But event that has a lot of unknowns in the equation and is merely an rough approximation.
You are lacking huge amount of information here.


Now a few words about the manifold itself.
I have a feeling length of intake runners is too short.
Also low manifold volume around last intake runner will be a bottleneck.

And as a last thing to consider. JTD engines are really not limited by the intake manifold design.
Sure increasing diameter of manifold entry could help a bit, but that can be done easily by modifying stock manifold.

In short, I think you should spend your money elsewhere.
 

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Discussion Starter #8
Thank you very much.

I don't have enough room for 4. cylinder. Because as you see it is touching fuel pump. I watched almost all videos and find lots of information about it.
I wish I had those documents to test the flow as its in video. Stock manifold is not useful to me right now.
I've checked the length of runners on original manifold. They are 74mm, and mine is 65mm, I can add 10mm I think. And Money is a problem but, its for my spare time. I have CNC, I have lots of Aluminium for my hobbies so, I wanted to give it a try.

In Turkey some of my friend told me entrance of runners is also important but It is the best possible way to not to put any screw in to manifold. All the screws are put outside.
 

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shut the runners to cilinder 2,3 and 4 off for the modelling, and see if you get better flow to 1 like that? as Tribesman said, only one runner will draw air at a time
 

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Sorry for the bad rendering, this is what I've read for good inlet design

P.S the fiat 20v turbo has the same design inlet manifold you can modify and use it.
 

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Discussion Starter #11
New flow design is coming. I hope I will finish it this night. And then I will see the flow one by one.
 

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Why you don't try to make a central inlet manifold? The side inlet manifold has some restrictions, they you can't eleminate. With a central inlet you have a way better airflow.
 

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Discussion Starter #16
Why you don't try to make a central inlet manifold? The side inlet manifold has some restrictions, they you can't eleminate. With a central inlet you have a way better airflow.
Actually, I've thought that, but don't know why I did not do it. I have to look at which parts I must move to make it like that. Do I have room at the back? also plenum shape near 4. Cylinder won't change and for symmetry, 1. Cylinder has to be like 4.Cylinder. I will look at that.
 

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Very interesting project!
In order to have a reference of what you're doing is better than OEM, you should draw the standard manifold and try the analyses there. Also you can have a look at the Audi R10 TDI racing car manifold design.
 

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Discussion Starter #20
I know the Audi design very well. but the space is problem in our engine. So I have to do like this. Now I'm manufacturing it. :biglaugh: Also with 4 point meth injection nozzle pipes holes ready for future plans.
 

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