[Half-Inch Stud]

Two Flow Tool schematics:

CYL Head to Vacuum Motor inhale to Venturi to atmosphere.
CYL Head to Venturi to Vacuum motor to atmosphere.

I will prefer the latter for least motor loading ( best CFM/Amp efficiency) for best CFM/RPM.

CYL adaption below shows the difference in 4" dia into COP versus 2.125" into Venturi
Tremendous preservation of motor flow velocity with the 2.125" into a venturi. I stoked.

[Tom Vaught]

You have the right idea, but I like to flow large cfm Holley Carburetors.

I have the pieces, just do not have the new House/Garages and power to hook it up where I am now. https://www.vortron.com/pdf/Z40e_Data_Sheet.pdf

600 to 1600 cfm at 70" of water test pressure.
Basically the same capability as the Ford Research bench but at a lot lower cost.

But your little device is somewhat the same as my set-up.

Vacuum Motors in home built Wood flow bench work fine but I am getting old and like the stuff already designed and built properly these days.

I use a Meriam Instruments Inclined 60 inch Manometer like this one:
https://www.che.utah.edu/site-specif...0Manometer.pdf

and Vertical Manometers also from Superflow

But you are on the right idea with your little rig you came up with.
probably a 10th of the power requirement of my set-up, and electric bill.

Tom V.

ps There is one speed shop in the Detroit area that built a custom flow bench that currently can match the flow of the Ford Research bench. My bench will also match the Ford Bench but it will be used for Carb work when I move into my new shop.

[Half-Inch Stud]

@Tom, that motor is a beast! The CFM is typical of these turbo impellers, and i certainly like the impeller diameter. I like it! That beast has the capability to flow exhaust systems.

I think the quietest setup can provide the most value. To work a head flow in a quiet room, at any particular valve lift, i like to dial the motor rpm and listen to the flow noise. Then try a few intake runners and see if turbulence goes away. A very big departure from collecting flow numbers. "What does it flow?" I dunno but it will flow extremely well with this intake, and not so good with that intake.
Just based on listening for choke mode turbulence.

Provided that all 8 runners flow without turbulence, i suppose the calibrated flow numbers would be good to know. I haven't got a calibrated flow "bench" yet due to lack of depression at high flow. 28" at 260 cfm should do well, and i may be there soon.

Venturi designed, drawn, parts in-hand. So i got some pipe cutting and linear tapers to putty up.

[Half-Inch Stud]

The Blue Valve Seals ( on the left) came in from Butler today. I proceeded to ruin 1/2 of them during install: some guide lacked chamfer and gouged the seals.

These seals were used on the RA IIs but sure didn't have install problems like these 48s. These 48s got some not-all SHARP Guides edges, as if some guides were installed upside-down. ( craaap-shop is the past).

I will likely need to break (cut-grind) the sharp edged guides down.

So, I will likely pick the best 8 for Intakes, then Exhausts from the spread of seal laying around: Blue rubber, Teflon, teflon-in-rubber, rubber(tight), and rubber(loose). Maybe buy a new set of Seals if they are truely the best ( i so highly doubt it).

Big Question: What guidance is there for the best materials to seal intake stems vs hot exhaust stems?

[Half-Inch Stud]

Ordered another set of the Blue Stem Seals.

Meanwhile, appears the Guide Cutting tool is excellent for dressing the sharp-sharp Guide edges down, using a couple turns by hand. Blue Seals now capable of bare-hand install.

Surprized nobody responded with preferred Stem Seals for Intake ans Exhaust stems.

Note: Intake Studs vs Exhaust Studs are evident; Color only real difference.

[Half-Inch Stud]

Fresh set of valve seals arrived. Was able to install without tools due to prepping the guide edges. Using the KD Spring Compr tool bought over 30 years ago, for spring install. 1.70" installed height,

Retainer-to-seal (>0.70") & coil bind both support > 0.650" lift ( gonna recheck when this step is done)
Was shimmed for 115-120 LB ( need to check ).