Turbo jet as a vacuum motor? And my brand new bench

[FireFox]

my question is do you think a homemade turbo jet would work as a vacuum engine..
I got tons of turbos sitting around...

example of what im talking about...
http://www.youtube.com/watch?v=BZoymnZRBVc

do you think a 600hp rated turbo would pull like 28inchs of vacuum at a reasonably safe rpm?
I think it could and more because they use them on aircraft to maintain hp at extremely high altitudes. I'm guessing with a turbo rated for 1200hp(ie borg warner s400 series)... i could get some serious pull at serious cfm

1200hp takes something on the order of 2000cfm
that would make one hell of a flow bench.


also i was thinking i could test turbo exhausts with this... just measure the cfm on the bench(top off) with the turbo jet running and hook the turbo back exhuast onto the exhuast of the turbo... any drop in cfm would mean a restriction?



Just wondering... because with ~10hp worth of vacuum I cant get 200cfm and i wanna do at least 300cfm with at least 10" depression at a reasonable cost.

i just tested my new bench,
i've only been able to pull 146cfm thru a 2.165 inch orifice (~5"h20 difference/2.5" rise on one leg) with nothing on top showing 0" depression(5" hole on top)

i got a 6.5 hp shop vac, 2.5 hp shop vac and a 12 amp vacuum
what should I be able to pull with this setup?

is the 6.5 hp overpowering the smaller vacs and sucking thru the weakest vacuum?


my setup i just got done...
still need some good sealant but i gotta get to the store to buy some.
but it shouldn't matter for the baseline test to see max flow

[FireFox]

im guessing based off this...
http://www.vortron.com/blowers.htm
http://www.vortron.com/pdf/z40e_data_sheet.pdf
their biggest being the z40-E compressor... which is good for about 1600cfm (800-1000hp on a car)
i should easily be able to run a turbo jet for my vacuum

what's everyone's input on my idea?

[1960FL]

Just wondering... because with ~10hp worth of vacuum I cant get 200cfm and i wanna do at least 300cfm with at least 10" depression at a reasonable cost.

Forget all the rocket engines and build a PTS 8 motor bench you can pull more than 28" at 300CFM. Stop looking at the marketing horspower that is just a factor of AC Watts converted to HP for advertisment and marketing it is not a true reprasentation of the Air Watts.


Rick

[FireFox]

I would love to get a bunch of quality blowers but first i wanna try and see what i can do with what i've got.. and if it don't work then i'll buy the plans and build from that.


i've always wanted to build a turbojet.. so why not try it out.
besides... if it works then you guys will have a much cheaper way to build up some serious vacuum.. and its portable




You guys have an awesome amount of knowledge on these 2 forums.
Thanks a ton.

i already tested a couple different heads and im in spec of published flow #'s. so hats off to you people



PS does anyone have a more accurate conversion formula chart
ie.. have flow at 10" want flow for 28" = 1.67

anyone got anything with more numbers like 8 to 21 or 17 to 40 etc etc

[Brucepts]

CFM Conversion you want= Tested CFM*(SQRT(Converted Static/Tested Static))

100@17" - 100*(sqrt(28/17)) = 128cfm @28"

200@18" - 200*(sqrt(25/18)) = 235.7cfm @25"

[Flash]

When i convert from 10" to 28, i go out one more number. 1.673 don't know if it real matters that much......................

O, and Firefox, Welcome aboard

[FireFox]

CFM Conversion you want= Tested CFM*(SQRT(Converted Static/Tested Static))

100@17" - 100*(sqrt(28/17)) = 128cfm @28"

200@18" - 200*(sqrt(25/18)) = 235.7cfm @25"

awesome
thanks
Until i get some more power... at higher flows i can only pull 8" test

[JakesPorting]

With the bench that i built i used 8 old vacuum cleaner motors from vacuums like that 12amp one you have a pic of some were mix and match but it works.

The bench i built will pull 476 cfm at 28" water with a 12" vertical rise on the inclined.

[FireFox]

476cfm
28" corrected or 28" true?


i can get 100cfm @ 8" with 17" incline

so like 187cfm corrected for 28"

[JakesPorting]

That would be true 28"

I can get a 400 cfm head to test at 35" with all the motors on. I like to test at higher depression but that is all my bench will pull with those motors.

Initially i run four motors and when i cant get to the depression i turn two more on then when i cant get there again i turn on the last two .

There are check valves on the four that i dont run all the time to keep flow loss threw the motors
at a minimum.