Added two motors to a Superflow 600

[John Haskell]

Recently was told of this site & boy I can use some help now.

I had read a long time ago that if we needed to increase the capacity of our benches, we could simply install additional motors to the case. Construct a wood box to enclose the motors, duplicate what air feed openings needed & your set.

Well, I have never ventured into the big heads before to need it so, no big deal. ------ But now I have the need.

So, two very-very good fellows added two of the recommended ametec motors onto the case, built a beautiful wood box & I was really impressed. The out side of the left wall has 2.1/2" holes cut into the interior of the motor plenum, then a 2" ID plastic pipe slid through the motor plenum into the main chamber where the flow selector disc is located, then the motors are installed / sealed over the 2" ID pipe. Of course, holes were bored for air entry INTO the motor box.

Then, additional inlet holes were bored into the intake / exhaust vents or grills to match the additional air. (When the back cover is screwed onto the case).

The bench peaked at 530 cfm -- .900" / 25", (not 28") with this 2.600 intake valve Dodge / Ford Pro-Stock head before any work began on the bench. Now I believe I have to see 630 cfm @ 28" or so. This at 1.200 lift.

Result, no change. ----- "ALL" motor rpm sure seems to be normal, the harmonics sound the same indicating to me anyway that they are all happy. The dip switches are positioned for max rpm.

I would have believed the bench would have pinned the vertical & inclined with this change. What do I need to do to fix this or am I just screwed with what I have. 1992 Super-Flow 600.

I also have Bruce's variable speed controller. (Cool).

Can / will you boys help me ? I'm right at 70 now so don't get to technical due to my full-full brain.

[RACEPUMPER]

John, just quickly, a few things to consider.
Your cabinet may be restricted and the flow amount pre modification might be the most you see.
Another more likely reason could be the measurement orifice. At 530cfm @ 25", if that's the peak of the orifice flow, it won't matter if you push another 6 motors through it, 530 will be the most you can measure until you switch to a larger one.
Somebody else will hopefully chime in with more sf600 experience than me but these are some basics to consider.

Jim

[Brucepts]

The largest orifice in the SF600 is 3.490" the rise on your incline is 13.87" from my notes, this would give you an effective range of 615 cfm with water gauges.

Something is restricting the flow path or you have a static leak somewhere since you are not able to get more than 25"

Try flipping DIP 6 to "ON" (up in a normal installation position) on the SSR control module although you said it sounds like it is running fine it could be not reaching full output. I have had this happen on some systems before and this solves that issue. In theory it is not needed but it doesn't hurt to try. If it makes no difference turn DIP 6 back to "OFF"

[John Haskell]

Thank you guys. The one thing I can't figure, I had the bench re-calbrated with the batch of plates from Super Flow. All the flow ranges were changed to just a couple of cfm lower from what came with the machine. The peak number originally was 601 & the new number is 590. So how can a bench be calibrated to 590 when it will not go but 530 with a head on.

I have the head fixture at 4.685" & the length of 4". The actual bore of the block is 4.705 & in this case the stroke is 3.25"

[John Haskell]

Super Flow made a call back. Claims there is no way to get the pressure I need by adding motors. Humph ! The fella is saying I need to buy a flow com. This is what you need to convert lower pressures to higher & flow com does just that. Just use lower pressure.

Trying to get more pressure isn't going to happen. Well Foooey. What a bummer.

I /we are still going to look at the insides to see if there is something amuck any way. Just haven't got to it.

He also tried to sell me a new bench of course. Said it was against company policy to help any one with this kind of need. Not to get involved w/it.

Oh well, the way of the world.

[Brucepts]

Any pics of how you installed the extra motors?

I think the 2" pipe could be the problem, least we can start there . . .

[86rocco]

Super Flow made a call back. Claims there is no way to get the pressure I need by adding motors. Humph ! The fella is saying I need to buy a flow com. This is what you need to convert lower pressures to higher & flow com does just that. Just use lower pressure.

That sounds like a really poorly thought-out or just plain lazy answer. I can't think of any reason why an appropriately modified SF600 can't be made to operate at a higher pressure.

And the math to convert readings from one test pressure to another is really simple, you don't need a flowcom, just a calculator. You multiply by the square root of the ratio of test pressures. For example let's say you've tested a head at 25" WC and it's 300cfm@25" and you want to know what it would be at 28", you multiply 300 by the square root of 28/25 which works out to 317.5cfm@28"

[larrycavan]

The largest orifice in the SF600 is 3.490" the rise on your incline is 13.87" from my notes, this would give you an effective range of 615 cfm with water gauges.

Something is restricting the flow path or you have a static leak somewhere since you are not able to get more than 25"

Try flipping DIP 6 to "ON" (up in a normal installation position) on the SSR control module although you said it sounds like it is running fine it could be not reaching full output. I have had this happen on some systems before and this solves that issue. In theory it is not needed but it doesn't hurt to try. If it makes no difference turn DIP 6 back to "OFF"

That's with a .62 coefficient on the orifice. Seems to me the SF600 calibrated at more like a .58 - .585 on all the ranges. That said.585 calculates to 580.3 CFM

The description of the added motor box connection method is difficult to picture. This doesn't sound right

a 2" ID plastic pipe slid through the motor plenum into the main chamber where the flow selector disc is located,

In any case the bench is pretty old and the gauge fluid may need to be changed. If it were me, the first thing I'd verify is that the gauges are reading correctly and there are no leaks in the lines....

[larrycavan]

I found my notes... Tom shared this with us about 10 years ago...

The Super Flow 600 uses the same Dewyer 246 durablock manometer as the one you have but with blue 1.91 fluid.

The Super Flow 300 used the same 246 manometer but with the
.826 fluid.

Going from the .826 fluid to the 1.91 fluid increases the range by 50 percent.

The SF benches had the following ranges:

SF 300 #1 = 25 cfm SF 600 #1 = 37 cfm
SF 300 #2 = 50 cfm SF 600 #2 = 75 cfm
SF 300 #3 = 100 cfm SF 600 #3 = 150 cfm
SF 300 #4 = 200 cfm SF 600 #4 = 300 cfm
SF 300 #5 = 300 cfm SF 600 #5 = 450 cfm
SF 300 #6 = 400 cfm SF 600 #6 = 600 cfm

in each case the orifice holes were the same diameter, they
just changed the fluid to allow 50% greater readings.

Example:
50 cfm time 1.5 = 75 cfm
200 cfm times 1.5 = 300 cfm etc.

I measured the orifices on the 300 and the 600 one time and they were the same.

The sizes were .857, 1.227, 1.770, 2.507, 3.059, and 3.490

The flow readings for the 600 chart showed the flows to be:
35.5, 71.5, 151, 299, 451, 604 cfm

You do the orifice size vs the flow and the discharge co-efficients were:

.593, .583, .593, .584, .592, .609

Quite a bit different from the typical assumed .62 number typically
assumed.

[Brucepts]

Super Flow made a call back. Claims there is no way to get the pressure I need by adding motors. Humph ! The fella is saying I need to buy a flow com. This is what you need to convert lower pressures to higher & flow com does just that. Just use lower pressure.

Less expensive way of going digital over the Flowcom would be the PTS Digital Manometer, I have a few SF600's using my DM or as Rocco stated just do the conversion math for your water gauges.

I think the people who have added extra motors to the SF600 simply made a box and added that on the side of their flowbench with no pipes, I think the pipe is the limiting factor and creating the restriction. My "take" on what is happening is the 8 motors now running are creating a larger depression before the 2" pipe of which the extra two motors can not over come so they have a 0 net effect of flow or even a - effect as they are now 2 open holes for static pressure to be lost 2. As I stated before it does not take a large static leak to have an effect on reduced cfm when running more motors.

Just my theory . . .