I have always been under the impression that one port is flowed at
a time.

Likewise, I've typically seen flow figures on a head quoted per port
(I/E). The aim being to reach for the highest common denominator
- except in special circumstances, you would want the ports to
flow the same as part of the process of building eight, optimized
single cylinder engines working as one V-8.

But I am out of my depth here.

.

 

Yes, you're right. Unfortunatly, I did not take a pic without the plenum mounted. To get the CFM data on each port,the head needed to be mounted and unmounted off the bench 8 times.
Tedious! Measurements were taken at lifts of .100" increments.
Took about 3 1/2 hours to do all 8. Did I mention tedious?!

 

On the topic of motors.

I've already mentioned it but it wouldn't hurt to repeat that for more
than one motor, most home garages would probably need some wiring
work unless you ran extension cords to other circuits (and there are
problems with this!) I think regular breakers are rated at 15A and
one of the motors above is going to put you pretty close to that.

Those of you lucky enough to live in the sun-belt might consider the
option of using an engine, instead. Provided you could run it outdoors,
a gas engine from Tecumseh, B&S, Kohler, Honda or whomever could
provide more HP for much less money than going electric and there
wouldn't be the need to make wiring changes to support the heavy
current loads a heavy-breathing system would need.

For example, 5 HP Hondas run from $160-$350. If you want to put a
'hurtin' on the Throttle Body, an 18 HP for $1,000 might be the answer.
These are new prices, the resourceful among you can do better, I know.
If you could score a used unit already set up for propane then you'd
be better off environmentally and you'd solve the stale fuel & varnish
problems associated with gas engines that stand for long periods.

Set the whole package on casters, roll it out into the car port and get
to work.

.

 

The geeks among us have a solution for that - rig a stepper motor to a
rocker-arm stud and write some software.

Check out the Flow Pro Automatic Valve Opener from Audie Tech.


BTW - If this wasn't a thread about a home-shop flow bench for 'Vette head
work, I would ask the question: "Why not build a base that would allow
the head to fixtured once and then enable all I/E valves to be tested
without having to move the head again."

.

 

(Edit: this may be what the piece of plexiglas is in the picture above.)

Here's another random thought for someone that actually goes ahead
with this project.

Instead of using a big wad of putty and shaping it into a venturi around
each intake port one after another, make velocity stack out of metal
or wood.

You could probably build a flange with four openings but since
consistency is important, one stack configured so it can be moved
across all the ports might be the better approach.

Yes, you need to consider port size differences. Make the stack to
suit the largest port you are likely to work with and then you only
need a little modeling clay to blend the transition.

I leave it to those with more experience to judge whether this wouldn't
be cleaner, faster and more consistent than shaping a large handful of
clay around each port you flow.

.

 

The JKM bench I use was at the house initially but it would blow breakers left and right. I think it takes about a 50 amp breaker; the same as my TIG welder. But it has two huge blowers; it can flow up to 48" but is good to about 650 cfm at 28".

The Audie unit, Flo-Qwik, or whatever they call it is what I was talking about. I've actually seen one of those in action and it did a remarkable job. It came within a few percentage points of a SuperFlow on the same head. But its capability for flowing larger heads and varying bore size isn't as good as with a larger bench.
-Jeb

 

I don't think that'd be a big jump at all. All you need is the ability to select between 4 different cylinder cutouts, then flow them one at a time, but without having to relocate the head.

I like the idea of using a honda motor, then you just need to find a large vacuum blower wheel to mount up to it. Now we're cookin' with gas!

 

That thing is cool... Very simple, but does the job at hand perfectly. Shoot, I have all the parts to make something like that here at work and probably won't take me more than an hour or two to write some software. Wonder how much they get for that guy...