How many cubic inches is it? or does somone know the interior dimensions: length, width, and depth? thanks

 

anybody crack one open?

 

If you have one available you can get a rough idea by measuring the inside deminsions. I did that with my TPI plenum. I added some volume to it by making part of the runners an extension of the plenum. I figure I increased my TPI plenum volume by 45%.

 

I don't believe you will be able to calculate plenum volume. It would
be better to measure it with liquid because of the unique shape.

 

I think someone on here said once that it's more than a 6 pack, but less than a 12 pack Seriously though if you look through enough threads I remember this being discussed once before.

 

Fill the thing with water and then empty the water into a beaker, or weigh it.

 

A 6 pack is 2.13 L or about 130 c. in. or about the displacement of 3 cylinders of a 355. I recall measuring an LT1 manifold that way, but my memory is a little hazy on the final number. I believe we didn't want the measuring fluid to go to waste.

I'll try it again. I think Yuengling is on sale down the street.

 

What ever the size of the plenum is it's too small, especially with modified
heads and or high RPM. I consider the TB to runner location even a bigger
problem. 1 and 2 runners are about 3" from the TB. 7 and 8 are about 13"
away, when they get their turn to breathe there's nothing left.

 

I sense the development of a new drinking game...

 

Not necesarily. It's not just particle velocity you need to look at. It is also the wave tuning of the plenum (as well as the runners). Those pressure pulses are travelling back and forth in the plenum at sonic velocity, which is about 3-4 times the average particle velocity. IOW, the trip along the 13 inch plenum length takes only about .001 second for the pressure waves.

Perhaps wet flow doesn't begin until you get into the runners (at WOT and higher rpm). That makes it a little easier to analyze.

Jon

 

I have a spare LT1 intake laying around that I haven't been able to sell yet. In the best interest of CZ28 I'll silicone up the TB holes, flip it over and see how many it takes to fill it up. I'll just do beer cans as a measurement and you guys can convert it.

 

I'm having a difficult time understanding the activity inside the plenum
at RPM. In my mind I see chaos above runners 1,2,3 & 4 causing
turbulence resulting in a flow blockage in the region. It's difficult for me
to imagine pressure pulses with this much happening, although I'm sure
these pulses play their role.

I know the intake works because I see the stock eliminator cars running
mid 10's. I also know there's a air distribution problem from reading the
plugs, back cylinders run rich.

What's the limit, how much power can these intakes support N/A?

 

how about drinking one beer and then use the can to add water,count the cans....that way you can drink the beer

 

and on a FI car 7 and 8 are lean...

 

We had a clean manifold, used the beer to measure and didn't waste it afterward. That's why the difficulty remembering how many cans it took.


As to how much power the LT1/4 manifolds can support, the runner cross section can be the limit if you don't want to weld on the outside of the runners. The short runner length limits the ram tuning to the 5th harmonic, which isn't particularly strong. This also limits the max power, especially NA. Remember it was designed for under 350 fwhp.

With the nicely radiused runner inlets, the tuning pulses only push the particles a little bit out of the runners. It may be a llittle difficult to visualize, but there are some good CFD pics of what happens.

Yes, unsteady gas dynamics are complex and not easy to visualize.