Lynn E. Hanover

You need air density, temperature at the air inlet, and barometer all corrected to sea level on a standard day (60 degrees) from SAE tables.



The second most overlooked item is two plane precision levels on the machine, and a system for adjusting for changes. Note that the longer the run of the output momometer (the closer to horizontle) the more sensitive it becomes. Also the more like a level bubble it looks and acts, thus the need for the level check between sessions.



If you use water instead of oil for indicaters check fluid levels before each session to avoid errors.



I added a long run of hose attached to a third monometer at one end and to a length of brake line tubing at the other. Good for probing for high velocity problems and pressure changes inside a port.



If you move too fast the indicater fluid will vanish from time to time, like having a butterfly snap shut, or the like.



If there is interest, I can Gin up some plans for a decent flow bench made from damn near anything at hand.



Newguy, what are you using for the blower?



I have a centrifugal blower from a tank of some kind. Its 24 volts but boy does it move some air.



I only speak 12A with carbs. I don't know what a DVI is ??????





Lynn E. Hanover

ColinRX7

Really?

Lynn E. Hanover

Yep.





A flow bench is can be thought of as three boxes.



The first box has the hole for the test pieces to sit on.



At the rear or bottom (makes no difference) of the first box is a big hole

that leads into the second box. There must be some system to open and

close off this hole with great precision. I used the flycut off-fall of making the hole.

The plug or throttle (sounds better) is mounted in such a way that it can be screwed

back into the hole. I mounted the plug on a long piece of 3/8" threaded rod.

A stiff bracket With a 3/8" nut brazed to it, close to the hole supports the plug

so it hits the center of the hole, when screwed in tight. The other end sticks

through the front of the box, through another 3/8" nut welded to a large washer,

and then into a handle or crank of some design. I used a wheel off of a shopping cart.



The second box has a hole that lines up with the first. The blower must be

installed so that all of the air it can collect must pass through this hole with the throttle.

The output of the blower will be free to escape into the second box. This box need only

be sized to fit the blower.



The blower may be as simple as an old shop vac.



Sitting on this box is the back box. The vertical box that will

support the meters (monometers) and cool stickers your friends put on it.



Pressurized air from the blower box will be free to move through the back box and

out the top of that box through a series of different sized holes. These holes are closed off

in different combinations to adjust the output to make the indicater monometer into the

center of its range. I used a thick board covered with a sheet of foam to just move

along the top of this box to do that job.



You install a tall vertical "U" tube monometer along one side of the back (vertical) box

with one end in the text box and th other end open to the room.



The indicater monometer can be a long glass tube (very cool) or just another length of 1/4"

plastic hose from sears. Sears has all of the flow bench parts. This monometer is installed

at about a 20 degree angle across the top front of the vertical box. One end is inside that box

and the other end open to the room. Some method of holding the tube straight is required.



I cut up some measuring tape refills to use as reference numbers and put them alongside

the monometers.



So air is pushed into the test box through your test piece, when the blower lowers the

relative pressure in the blower box.



You control how much airflow it can get with your throttle wheel or crank.

You clamp your test piece over the hole. You adjust the throttle to get 6" of water on the

vertical monometer. All testing will be at 6" on this piece from then on. The throttle controls only

the test vacuum or depression.



The output of all of this flow is now escaping through the holes at the top of the third box.



Cover a few of the holes at the top of the third box and watch as the latteral monometer begins

to move. It is measuing air pressure in the blower box. It is very sensitive. Go slow. Keep the throttle adjusted to maintain 6" on the front box.



Once things stablize, note that the smallest change to anything in or even near the test piece, makes a big change in the monometer.



Shazam!!!



You have a flow bench at $6,000.00 below retail.



Now let your mind wander around this shape for a few seconds. Does it have to be a box? If I knock off some of the plastic parts from the shop vac blower, could this fit in a grease drum or a nail keg. Could you build this into a work bench and connect the blower box to the vertical box with a 6" flex hose. Just make a cover for the test hole when not in use?



If I had two old shop vacs and inverted the can of one onto the motor section of the other and that would be the top box.. and the test box connected with the flex hose???



Could the throttle be a big gate valve in the flex hose to the test box?



So long as there is a throttle system on the suction side, the whole unmodified shop vac could sit inside a drum of box of some kind, with the back box on top of that?



The answer is yes to all.



Drawings to follow.



Look at Paul Yaws web page for a totally cool home made flow bench. www.yawpower.com





Lynn E. Hanover

Mr. Midas

Wow! This is really good info! Thank you for spending the time explaining all of this stuff.



My thrown together flow bench is very very basic and runs off of my house-vac , but I was able to get some good comparative values when I did some experimenting with the clay. I plan on making one according to your description when I need real precise readings.



I feel so privileged to have all this input. My punny thread is not worthy of the voluminous amount of info you're giving out. If you do plan on going into greater detail about flow bench construction/testing, I seriously think it would be highly appreciated arciveable meterial in its own thread.

Its just to good to be lost in a thread about epoxy...



Note:

The S5's intake is a variable dynamic intake(VDI) it utilizeses the pulses from the intake closing of one working chamber to charge the other working chamber(and vice versa) via two different length runners. Nice manual illustration/explaination attached.

[attachment=34275:attachment]

j9fd3s

the rx8 goes one step better, and that is actually to close off the ports/runners that arent being used. also the 6 ports are gear driven from an electric motor

rfreeman27

A Picture is worth a thousand words

Lynn E. Hanover

I have two of the three pictures done and in MSPaint. It is an old version. I bought a used computer that works well after my new computer blew up. Threw a rod. Got oil all over the rug.



I need a modern version of MSPaint, or, some freeware that can save these pictures as JPGs.



Any ideas. Don't go into the weeds too far. I can just barely understand computers. That first one was a Coleman. Powered by white gas. This one is solar powered.



Lynn E. Hanover

heretic

My computer is powered by Alvin and The Chipmunks running in an excercise wheel, and is part pocket calculator, yet it runs PhotoFiltre just fine. You can do mild editing, like text insertion and the like, and it can be downloaded for free. I don't remember where I got it from but the usual gang of search engines should pick it up.



Nice thing about junk computers. They're still state of the art relative to when they were new, yet they can be had for free or very close to it. More money to throw at the car!

Lynn E. Hanover

Indeed it is.



Here is a picture.





Lynn E. Hanover

Lynn E. Hanover

Here is the second picture.



This is the blower box. It can be a second box or can be produced by extending the front box

and installing a partition. It houses the blower (whatever you will use). The suction side of the blower

must be sealed to the throttle hole by a foam gasket, hose, silicone etc.



The output of the blower is free to escape up through the back box. There can be no air leaks at all.



Install a leveling system for the machine, and two planes of levels affixed to the test piece surface.





Drawings to follow.





Lynn E. Hanover