Okay, I Gotta Ask...

[Dave70968]

I was privileged to spend an afternoon with @swampratt (thanks, Jeff!), and learned a lot in just a few hours. One of the things we talked about was fuel atomization. A thought occurred to me, and I have to wonder: has anybody tried actively stirring the mixture as it goes through the tunnel ram? Think of an engine-driven fan (probably several, ganged) in the tunnel, stirring to promote turbulence (and thus mixing)? Yes, it'd require a larger volume to compensate for the air drag, but it seems like a way to homogenize the mixture without resorting to a supercharger.

Just a thought. Please tell me what I'm missing.

 

[mightymouse]

Tunnel rams are designed so that the intake manifold runners are longer and straighter than either a single plane or dual plane intake. Superchargers actually compress the air/fuel mixture, resulting in a denser fuel charge (which is why they are sometimes referred to as "Kompressors" or compressors). Fans in the manifold runners would not make power like a supercharger does.

 

[Gunbuffer]

That would give mixing, but slow down the fuel. The time that any one molecule of hydrocarbon spends in the intake is infinitesimal.

 

[swampratt]

I have read about people building deflectors and stick them under the carb in the intake manifold and the pressure waves and energy in there destroyed the thing and the engine tried to eat it.

Things not solid in an intake runner will get destroyed in my mind.

To really blow your mind look up wave tuning and 2nd order harmonic
scroll down to post 81.
https://honda-tech.com/forums/k-series-153/2nd-order-harmonic-intake-manifolds-3110729/page4/

Some stuff on wave tuning. just a dip in the bucket.
https://www.speedtalk.com/forum/viewtopic.php?t=35634

Some on calculators and velocity of sound so they call it.
http://www.velocity-of-sound.com/velocity_of_sound/calculator1.htm

I do know for power many years ago a BBC with tuned IR manifold with velocity stacks seen 3 PSI of pressure with 18" stacks.

Yes 3 PSI so basically the velocity was great enough to produce boost in a naturally aspirated build.
Ram tuning .. The stuff will blow your mind HA!

Some heads have swirl vanes cast into them.
Look that up also.
It is never ending.
You need to drive my 47 dodge truck. Not ridiculous fast but for a junk build it is not too bad.

 

[adamsredlines]

I think a tunnel ram with a fan is called a supercharger

 

[dennishoddy]

Back in the day through JC Whitney you could buy screens to put beneath the carb that was supposed to further atomize fuel sprayed through the jets. At the time I was driving a 66 Ford GT 390 burning 100 octane that got 16 mpg like clockwork. As I was driving between Kansas City and Ponca every other weekend I had a pretty good handle on the mileage.
Since it wasn’t expensive, bought one of the screens to try out. After several more trips, it did show a 1 mpg improvement. So it kinda worked.

 

[beastep]

They used to sell a device like this and I forgot what it was called. One went under the carb. Another was in the air intake before the manifold on the FI cars. I dont think they ever worked.