New PTS build - help with numbers

[Adrian]

Good to be among all you good flow folk!
Have just started a PTS build (thanks to Bruce and contributers!) and need some guidance on how many motors I should start with.

Will be mainly flowing classic BMW and Guzzi motorcycle heads: Hemi chamber; max inlet valve size 46mm; port diameter approx 38-40mm at narrowest. Bore diameter 94mm.
Could do some basic numbers with assumptions but suspect the real world knowledge bank will be more accurate. Any punts at what this head might flow at 28"?

Looking at using Ametek 19996-00:
http://www.rossbrownsales.com.au/files/ ... asheet.pdf
About 50 cfm @ 44 "H20.. approx 5A @ 240V

Will be wiring to terminal blocks at all 8 motor locations to simplify future expansion but want to keep initial motor cost under control..
Have 60amp (3 phase) in shed.

Adrian

[Tony]

Yes, you are definitely on the right track.

Nothing worse than building a fine bench, then thinking gosh, darn, I wish I had fitted more motors but its too late now.

Plan to squeeze in as many motors in as you can fit, as you are not really power limited, but it may require some strengthening of the motor mounting board.
56 inches is about two psi, and that is 288 pounds of air pressure per square foot. That is a serious load.

It sounds like you have already figured all this out, but the very large forces involved usually come as a shock to most people once its pointed out.

[Heph]

To have a rough idear the head flow, just refer to the BHP produced per cylinder.

Let's say it produces 50 Bhp / cylinder, it will flow around 50 CFM @ 28". You then have to add some safety margin and provision for the benefit of headwork !

I started like you with 8 locations but only 2 motors. I now have all 8 and am glad I started with powerfull motor.
You never know what you will flow next and at which pressure

[Adrian]

Thanks for your help Tony and Heph.
50hp per pot happens to be about right for these motors after modding so reckon I'll go for 4 motors so there's some left in the bank.
Cheers
Adrian

[RACEPUMPER]

Looking at using Ametek 19996-00:
http://www.rossbrownsales.com.au/files/ ... asheet.pdf
About 50 cfm @ 44 "H20.. approx 5A @ 240V

Great motor choice. They flow 80cfm @44" not 50. With 4 your bench should pull 280-300 cfm @ 28". Pretty decent port

Jim

[Tony]

Great motor choice. They flow 80cfm @44" not 50. With 4 your bench should pull 280-300 cfm @ 28". Pretty decent port
Jim

Jim is definitely "Da Man" when it comes to questions about motor choices.

[Adrian]

Looking at using Ametek 19996-00:
http://www.rossbrownsales.com.au/files/ ... asheet.pdf
About 50 cfm @ 44 "H20.. approx 5A @ 240V

Great motor choice. They flow 80cfm @44" not 50. With 4 your bench should pull 280-300 cfm @ 28". Pretty decent port

Jim

Thanks for that Jim, yes 80 cfm...
@ about 5.2 amps each so between 15-16 cfm per amp - that's pretty good from what I've read on this forum.
~ 300 CFM will be more than enough I reckon.
Only place that seems to sell them is Ross Brown - $120 + GST. You wouldn't happen to know of another less exy source?
Adrian

[bigblock57]

Try ebay "flow bench" they have 6 motors for $519 I tried to post the link but it didn't work for me

[Adrian]

Roger that @bigblock57 - thanks

[RACEPUMPER]

Only place that seems to sell them is Ross Brown - $120 + GST. You wouldn't happen to know of another less exy source?
Adrian

Yes, Ross Brown Sales. Ametek distributor. Was that trade price?

Jim