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Intake Manifold Design for Diesel Engine - IAT, Heat Soak, Gasket Problems.

General engine tech -- Drag Racing to Circle Track

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emre2blue
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Intake Manifold Design for Diesel Engine - IAT, Heat Soak, Gasket Problems.

Post by emre2blue » Thu Jun 06, 2019 9:36 am

Hi,

I'm having problems with my IAT, and Air Flow in my Turbo Diesel Engine. I have a GTB2060VKLR Turbo, with 10+0 Billet Compressor Wheel.
Bigger Intake Manifold ( Bigger plenum, and Bigger Inlet ports+runners ). I'm getting new tune for my car. And Yesterday, My Tuner said to me that my AirFlow data from MAF is low, at giving Boost pressure.
He told me to check for the IAT. And I did some data logs today. Ambient is 29*C today. IAT can climb upto 62*C. I'm using water 2 air Intercooler by the way.
I know it has some capacity issues. But he thinks it is not the main problem for MAF readings.
He thinks that my Intake manifold design is not good. And that's why MAF before Turbo has lower readings. I will attach my design and Stock Factory Intake manifold to you.

Here is my thoughts and Observations about IAT

1) After I drive alot Intake temp is sitting around 42-44*C
2) I know My Cooler is not working perfect, but heat soak of the Intake manifold is huge.
3) After I get datalog. I opened the bonnet. And check for the cooler-core and Manifold temperatures, I cannot touch the manifold. But Cooler-Core is around 30-35*C
4) Because of Intake manifold is directly bolt-on to the head of the engine. It heats-Up very fast.
5) Original Stock Intake manifold is also made from Aluminium. But has lower plenum volume, and 42mm Inlet port diameter.
6) My Billet Manifold has more plenum volume and bigger runner diameters. Also Inlet port diameter is 72mm
7) My Billet Manifold thicker than stock one. And Maybe It heat soak more, And TMAp sensor is connected to this metal. This causes sensor to measure more hot than usual ?
8) I have a 3 times thicker front radiator for my Cooler Setup. I will install it soon. Maybe It will help me to get a better IAT.

For the MAF readings and Volumetric Efficiency.

1) He told me My Intake manifold is choking the engine for about %10 VE
2) He says similar setup car have 1600mg/stroke but Mine has 1400mg/stroke
3) He says My VE is about %80, and it needs to be around %90-%95
4) My car has a ported head also. I use Stock CAM profile, Stock Inlet and Exhaust Valves. Only port entrances are bigger. And Merged (8 small ports to 4 bigger ports)
At next to Valve area head design is stock. My Idea was only merging two ports into one. To make a easier manifold design.
5) A Friend of me told me that my bigger entrance is slowing down the air, thats why car can not breath enough... For a Turbo engine how this can be possible ? at 2.5 Bars Boost?

Can you help me to understand it ?
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naukkis79
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Re: Intake Manifold Design for Diesel Engine - IAT, Heat Soak, Gasket Problems.

Post by naukkis79 » Fri Jun 07, 2019 11:17 am

That intake is about as bad as could be, head has two different intake ports which flow differently and that flow can have massive turbulence in huge and short intake tract.

Make intake runners much, much smaller and if there's space, much longer.

emre2blue
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Re: Intake Manifold Design for Diesel Engine - IAT, Heat Soak, Gasket Problems.

Post by emre2blue » Fri Jun 07, 2019 4:52 pm

I think I will first buy a second hand proper head. This is necessary. And leave it stock. Maybe I can redesign my billet manifold ports to match its size and dimensions to use the plenum. Or I can go all the way back to full stock. It will be a costly education #-o

For the port shape as it is, you tell me its worst right? :oops:
I could not make the runners longer because, Manifold is touching the High-pressure pump.

naukkis79
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Re: Intake Manifold Design for Diesel Engine - IAT, Heat Soak, Gasket Problems.

Post by naukkis79 » Fri Jun 07, 2019 5:23 pm

emre2blue wrote:
Fri Jun 07, 2019 4:52 pm
For the port shape as it is, you tell me its worst right? :oops:
Best performing intake runner is round shape, not any bigger than what is needed to match head flow. Original intake manifold has own runners for swirl port and high flow port - it's needed to get good flow for such a different port shapes as their flow speed differs a lot. When changing to siamesed runner manifold optimal runner size would be only little bit bigger than that original round runner - so it flow about as much as the head port.

With a too large intake runner flow velocity is low - and worse, as head ports biases flow to other half of runner the other half of that runner probably flows air backwards slowing actual flow motion even more.

Original design is pretty good - if you could not equalize intake valve flows there's not much sense to convert to siamesed type manifold - and that in cylinder motion which is achieved with that independent swirl port is crucial part of burning fuel in direct-injected diesels - chasing only for more intake flow isn't probably helping to get more power.

emre2blue
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Re: Intake Manifold Design for Diesel Engine - IAT, Heat Soak, Gasket Problems.

Post by emre2blue » Wed Jun 19, 2019 1:54 pm

What do you think about, If I have a stock head, and only bigger plenum, How will help me ? I've bought a second hand head, And new Manifold. My Euro-4 Head ports are 1mm small in diameter than Euro-3 Engines. I've learned that They put Euro3 Manifolds on Euro4 Heads and port match only.
I will give it a try.

Also I've dynoed the car 282Hp/528Nm Torque not bad, but VE is not good. You can check the Datalog And Dyno Chart.
https://www.youtube.com/watch?v=NApYt8X ... l=emresuat

Also Bought new Intercooler, Not the best one but best of that I can find in Turkey. German Made, 8.5Lt - 21.6" x 9.4" x 2.5"
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gruntguru
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Re: Intake Manifold Design for Diesel Engine - IAT, Heat Soak, Gasket Problems.

Post by gruntguru » Fri Jun 21, 2019 1:42 am

If the "VE" numbers in the printout are to be believed, you do not have a flow restriction. If you plot the VE vs rpm you will see it is pretty flat over most of h rpm range. If you had a restriction, the VE would be rolling off exponentially with rpm. A better cooler will no doubt help.

Is the turbo stock? It looks like you need a bigger turbo especially hot side. Have you measured exhaust manifold pressure?

emre2blue
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Re: Intake Manifold Design for Diesel Engine - IAT, Heat Soak, Gasket Problems.

Post by emre2blue » Sun Jun 30, 2019 3:02 pm

I've finished Intercooler Installation.
Image

And did some tests. IAT = Ambient +17*C Max :shock: (After 4th gear WOT from 1500rpm to 4500rpm then 5th gear WOT until 4000rpm ) Ambient was 30*C. There is lag but I don't and won't mind. Turbo is not stock it is GTB2060VKLR + Ceramic Ball Bearing + Billet Wheel. Stock one is GT1756, I have also 2.5" full exhaust system. I have made the exhaust manifold and I have an EMAP sensor port in it. I have the sensor but I could not finish the sensor monitor.

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