NRE Blower/Head flow "Bench"

I want my blower black! Just paint?

Brandon Booher
NHRA TAD #34

 

Waiting for it.

 

I take it that the electric motor and speed controls, normally used to do the normal Spintron valvetrain analysis, are being used to spin the blower at different speeds/boost. And they are doing cylinder head port work much like you would on a Superflow air flow bench except at XX boost psi vs using the standard 28".

That's my assumption.

 

It is a SpinTron machine, just not being used quite in the same fashion. You can read SpinTron on the case. Pretty nice setup! Hopefully the screw doesn't scream like the fuel blowers. If you're within 2 blocks, you know that thing is running.

 

Still has the "shop vac" on the exhaust. Interesting

 

Looks like fun! How do they lube the screw I wonder?

 

Maybe Will can verify this but from my perspective they are using the spintron to only drive the blower thru the crankshaft, there is no cam on this engine , that is why there is only a valve opening fixture on the intake and not rocker arms.

In fact this is a big time flow bench in which you can teorically test each cylinder for same flow or diference in flow in a completed engine!

You can place "flow sensors" before and after the blower to record changes ...

Great idea if I understand it correctly

but hell what do I know???

 

spintron

we tried spinning a psi screw on our 100 hp spintron at 115 over and it did not have enough power to pull it at higher rpms either they are not spinning the blower very fast or or?????????

 

Bill Miller has a really cool video of testing a blower.

http://www.bmeltd.com/supercharger/index.htm

 

I don't beleive there are more parts spinning than the crank, pulleys and supercharger. I would geuss they have the bottom of that cylinder plugged, but not rods or pistons in it, probably just bobweights for the balance. The hose appears to be "stuck" into the side of the cylinder, not the exhaust port, which tells me its setup to test the intake port during this picture.

 

Would they need to overdrive it much at all? They are only flowing one intake port perhaps at 65 psi. Maybe there's a boost pop off valve somewhere on that setup

 

i understand it takes 750hp to get the blower at 50pds on a complete engine but i believe if you are flowing only one port at 45 pds them a 100hp is enought however the real advantage of this system is that you really know how much air each cylinder gets with the blower=manifold and head combo...

 

I would hope it doesn't take that much hp to get a screw to 50 lbs or somebody is doing something wrong. We have a screw air compressor that is 3 times the size of the PSI that runs half or more of our 100,000 sq. ft building at a consistent 109-110PSI with a 150 hp motor on it.

 

I reduced all the data from the original PSI blower dyno testing in 1987. This was for the lower flow 200-A rotors. I just pulled out all the old blower maps. At 9500 blower RPM it took between 216 HP and 276 HP depending on the manifold pressure (max of 30 psig at 9500 RPM). The highest RPM we tested the PSI at was 12,603 RPM and that took 328 HP.

For a modern TAFC at 10,000 RPM at 92% over that puts the PSI rotors at 19,200 RPM. At this blower RPM it takes almost 500 HP to spin the PSI (45+ psig manifold pressure). But this is much less HP than any Roots (standard or high helix).

Mike - what is the basis for your low HP numbers for the PSI?

Patrick Hale
www.DragRacingPro.com