Home built flow bench

[Kelly Murray]

I've built a flow bench for about $125, using two new $30 leaf
blowers, and one free junk vaccum cleaner,
and two $25 4x8' 5/8" pressboard sheets, and about $15
worth of wood screws, glue, calking, plastic tubing and a few PVC
parts, and some sheetmetal.

I modified the flow bench described in the Oct and Nov 1983 issues
of Popular Hot Rodding.  In particular, the primary modifications was
to use a single plenum configuration with external blowers,
rather than use internally mounted blowers that sucked from on side
of the cabinet, and blew into the other side.
The single plenum setup reduced the size of the cabinet, which takes less
floor space and required only 2 4x8 sheets of wood, made the cabinet stronger  
and also made it easy to use type of external blower/vaccum source.

It generates only about 5in of water for a full-open Ford 460 intake,
but will do 8-10" under low-valve lift conditions.  You can get
useful data with only 5" -- i.e. you can observe differences.
A Flow bench does not have to exactly duplicate engine conditions,
the flow results are highly correlated with engine performance,
increase flow on the bench increases flow in the engine.

I recently pulled mine out of the corner of the garage, and fired it
up and took pictures with my digital camera.
I threw together a webpage with them:

http://www.htrd.com/kem/flowbench


Cheers,
 Kelly Murray  kem at franz.com   Hercules, CA
 '63 Falcon Roadster 460 (memorial day results:  12.50 @ 112mph)
 '70 Mustang MachI 351W  (for sale???)
 '69 Chevy Suburban 350  (needs front disk brake conversion! help!)