I'm working on designing a custom intake manifold for my 2JZGE project.

Currently I have a stock lower intake manifold that I cut off near the injector ports. I was going to weld ross machining oval runner extrusion to this flange, but there is a large mismatch in port size. Also, the injector ports are oversized and require an additional o ring to properly seat standard bosch EV1 injectors (14mm).

I've been working on designing a custom cylinder head flange without injector ports. I plan on welding two injectors ports midway up each runner.

I'm using a Sharpe 4" hemisphere for the end of the plenum.

For the top of the plenum I'm using a 4" 11ga 48CLR bend from global tech.

For the leading bend on the plenum I'm using a 4" 11ga 12CLR bend from global tech.

http://www.globaltecheng.com/elbows.htm

http://www.sharpeproducts.com/

Overall I'm looking for some constructive critism. I'm going to run the manifold is CosmosFloWorks when I get the design finalized. I have high hopes for consistent cylinder to cylinder flow.







Justin

 

Reminds me of a Hypertune manifold... with longer runners and a smaller plenum.

 

Looks good Justin, but I think that you will be starving the farthest two runners for air.... I'd make that end a bit larger.

What is the volume of the plenum?
What size are the runners?
Are they tapered?
Velocity stacks inside the plenum for each runner?

 

are you using sheetmetal function of solidworks or is that an assembly?

 

The basics look good.

If anything, I might use a less severe taper in the plenum heading towards the last runner and, if there is room, a bit more width in the base plate. The entries to the runners are essentially 'shoulder to shoulder' all the way down, so more room above and below may result in less turbulence at the point where the air is splitting between each entryway. Or, maybe not - hard to tell for sure from the illustration.

 

I didn't use the sheet metal key in solid works. These are pictures of the assembly.


I'm using RMR oval extrusion for the runners:

http://rossmachineracing.com/ovaltube.html


I'm using RMR oval velocity stacks:

http://rossmachineracing.com/ovalstack.html

I'm going to run to play with the manifold some more and have my friend run it in CosmosFloWorks. I have high hopes as my friend designed a similar shaped plenum for a datsun L28 that performed well in floworks:

 

can you simulate valve opening and closing events on those programs you use ?

 

One thing I've seen help the flow of intakes is raising the velocity stacks off the floor of the plenum. At first it might not make sense, but it helps reduce friction losses, and if you use radiused velocity stacks they pull air from all the way around them, not just above as well. It's hard for some programs to simulate it though. Once you get the plenum shape you want maybe you can take the manifold to a flow bench?
Good luck, nice to see someone making such good use of the program.

 

Here are some initial results for the REV 2 plenum flowed at 25" H20 with runners going down to factory port size. There is flow left on the table hear having the runners neck down to the factory port cross section.







Regards,
Justin

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaveF &raquo;</TD></TR><TR><TD CLASS="quote">can you simulate valve opening and closing events on those programs you use ?</TD></TR></TABLE>

I don't know that CosmosFloWorks can do that. I'm having a friend of mine run the flow simulations. I'll ask him about it.

Regards,
Justin

 

I agree with Niles. From a velocity aspect you want the velocity stack off the "floor" of the plenum. This may require modding your plenum too.

 

I agree that ideally it would be nice to have the stacks raised from the floor to get them out of the boundary layer. I'm trying to use off the shelf part to build this minus the head flange. Thats the only reason I'm not going that direction.

Regards,
Justin

 

DUDE!!!! Ross Machine Shop is up the street from me. They did our manifold on our 2RZ motor and its an awesome piece

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin Olson &raquo;</TD></TR><TR><TD CLASS="quote">I agree that ideally it would be nice to have the stacks raised from the floor to get them out of the boundary layer. </TD></TR></TABLE>

I would be more concerned with the boundary layer separating in the diffuser section.

From what I had come across in my thermal/fluids coursework, everything to me suggested that flush velocity stacks would be the best way to go (from a flow standpoint). Since everybody had always been using raised stacks, I spent a bit of time doing some research and picking the brains of people who knew their stuff (other thermodynamic engineers with more experience). The only thing I really found suggesting a raised velocity stack was when the stack inlet radius was toroidal (meaning, not a constant radius). For a constant radius inlet, the stack was suggested to be flush against the floor. This was in an old ASME publication that a friend dug up for me. I've seen this topic touched on in fluids textbooks in the head/minor loss sections and usually it's just a chart showing flow loss 'K' coefficients for different entrances... and I've come across some text books that lead me to different conclusions about reentrant inlets.

On another note, what sort of flow conditions are you using for Cosmos?

 

I would put a TB blade in the mix ...

That effects most of the sim I have done with carbs

to EFI ....

 

i've got a 1/2" ge head flange sitting at my house. doesn't have port holes in it becaue my water jet company screwed it up.

i've got the cad file if you want it or i can sell you this flange for dirt cheap.

awsome work by the way. i was just going to start welding **** together and see what happens.

have you tried using a straight pipe on the back of the plenum? looks like that slight curve would be a pain in the *** to make.

 

Can cosmos not test under positive pressure?
testing under vacuum is only going to tell you so much.

 

Dave, There is a pressure drop across the manifold. Otherwise there would be no flow. The pressure drop can be increased to simulate a turbo application. This is just where I started. I'm adding a throttle body among other things to the model to try and get a more accurate picture. Once I've done that I'll hopefully post some more data.

Regards,
Justin

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin Olson &raquo;</TD></TR><TR><TD CLASS="quote">Dave, There is a pressure drop across the manifold. Otherwise there would be no flow. The pressure drop can be increased to simulate a turbo application. This is just where I started. I'm adding a throttle body among other things to the model to try and get a more accurate picture. Once I've done that I'll hopefully post some more data.

Regards,
Justin</TD></TR></TABLE>

Thats not really what I was asking, what I want to know is if can you blow through the inlet, 50 lbs/min at 40 PSI?

 

The flow rate will be determined by the pressure drop from the throttle body to the runners.

Justin

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin Olson &raquo;</TD></TR><TR><TD CLASS="quote">The flow rate will be determined by the pressure drop from the throttle body to the runners.

Justin</TD></TR></TABLE>

So does that mean No?

 

yes, you can set a higher than atmosphere pressure in flowworks to sim turbo applications.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dfoxengr &raquo;</TD></TR><TR><TD CLASS="quote">yes, you can set a higher than atmosphere pressure in flowworks to sim turbo applications.</TD></TR></TABLE>

What is the unit of flow?

Can you blow through the inlet or is it drawn through the runners?

I'd really like to find this program and play with it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tepid1 &raquo;</TD></TR><TR><TD CLASS="quote">Looks good Justin, but I think that you will be starving the farthest two runners for air.... I'd make that end a bit larger.

</TD></TR></TABLE>

+1. I think the curvature of the manifold towards the rear 2 ports will diverge air from flowing back there with any ease.

 

you can convert to any unit

theres no such thing as "blowing" or "sucking"

there is a pressure at the inlet and at the outlet, and the pressure drop creates the flow, like he was saying.

you can set the inlet to say 24.7 psi for 10 lbs of boost, and then set a flowrate for the outlet, or something like that.

-derek