How many of these??????

[bruce]

Those plans are missing a page between 6 and 7?

[gavinator68]

DARN IT!!!!!!


You are correct bruce.

[bruce]

But from what I read . . . looks like another set of plans the "forum minds" will have to work the bugs out of.

[gavinator68]

ok so far I have determined that this stuff doesn't come EASY!!!!!!

I have a plan'ish in my mind but don't know how to convey it in words. But I will try...............the goal first.

I need to achieve 250 - 300 cfm @ 28" to test VW heads with valves that are 1.57 intake and 1.39 exhaust.

I can use a cylinder from an engine as a bore adapter. That will sit on a settling chamber about 6 cu ft in volume. I will pull the test pressure sample from the upper corner of the plenum. I think I can connect a 1-1/2" or 2" pvc pipe to the lower portion of the plenum and run it about 48" across the cabinet and into the vacuum box with 4 of the surplus 1234 motors. I think I can put the averaging pitot tube in the middle of the pvc pipe with flow straighteners on each end, near the settling chamber and vacuum source.

Let me know if I am on track here...............

My plan to control test pressure was to use a pvc ball or gate valve inline before the vacuum source box.

Will this work?

What I haven't figured out is how I am going to get the flow to reverse without turning the vacuum source box around. Can I run a second pvc tube out of the source box and back into the plenum with a ball valve at the other end of the first tube to close of any recirculation back to the vacuum source?

Cheers

[49-1183904562]

Gavinator68;

Welcome to the forum , My suggestion to you is read, search and read. All of your answers are provided to you free here on the Board courtesy of Bruce (who wishes he could be in the shop making really nice parts for us all). All of us who have stumbled here have looked for simple solutions to a complex problem, I will assure you that the answers to our questions are here on the board with a lot of opinion and knowledge attached. Use the search tool!

Your bench can be bidirectional or suck only, it can be Pitot or Orifice plate it can use a big blower or vacuum cleaner motors, it can be digital or use home made Monometers; But if you spend the time and read you will learn that each of has our own opinion and there is NO simple easy magic bench out there. Save the $40 on the mecdog plans as they are useless and make a donation to Bruce through paypal.

As for the answer to your question if you want to have a bidirectional multi motor bench you will need to plumb both sides of the motor box for air source and supply, you must control the source air flow and supply airflow (Switch modes suck-blow) and you will need to figure out a one way valve so you do not suck back through the idle motors.

Hope this helps;

Rick

[gavinator68]

Thank you Rick..............I have been hanging around and reading everything I can get my hands on for about a month or so. If you were to ask my better half she would say it "has consumed him." When people say read the board then and read it again and again............ it must mean something, so that is what I have been doing. This is such a wealth of knowledge it is just amazing.

When you say I must control the source and supply do you mean something along the lines of........

Vacuum box with an inlet open to room air so as to provide a source of air for the motors in the exhaust test mode and a seperate outlet on the opposite side of the box to feed the plenum in the exhaust mode, with a control valve of some sort to regulate test pressure? The intake test mode would be the exact opposite just as described in my last post.

And.................. what about the averaging pitot sampling of the exhaust mode, can that be done through the same type of arrangement as I described above but in the exhaust feed tube to the plenum instead of the intake suction tube?

If I keep the length of the PVC from the plenum to the vacuum box sufficiently long and have the averaging pitot in the middle of that tube will I need to be overly concerned about how "straight" the air enters the tube? If that is a fair statement then how long should that tube be? I only ask because one of the systems I have seen, the quik flow, it seems is a reletively short test element and they use a flexible corregated hose to connect to it at both ends.

And finally.......... can I feed the exhaust mode into the plenum and out the bore adapter without any turbulance issues being created in the bore adapter or should a flow straightener be added to a feed tube for the bore adapter in the exhaust only testing hole in a two hole benchtop?

I know .............. very long winded.

P.S. My bench will utilize the FP1 system.

[49-1183904562]

[color=#000000]Guy

[gavinator68]

I have the advantage in the woodworking department in that I am an accomplished furniture maker and have a full shop at hand.

Any input on the size of the tube going from the plenum to the vacuum source based on my design needs? Bruce was mentioning that 2" may be too large for lower lifts?

Anyone?

Thanks for all the help so far.

David

[bruce]

Just a quick reply here, if you go FP1 the 2" will work.

[gavinator68]

Bruce is that due to the digital capabilities vs. the manual nature of the manometers? What will the flow limitations of the 2" diameter tube be with the FP1?

Bruce .......... what is your lead time on the averaging pitot tubes? I will need a minimum of two I think?

Thanks guys,

David

[gavinator68]

Oh and how long should the sampling tube be if there are NO bends? Just going from the plenum to the vacuum box.

David