Superflow calibration plate - Flowing @10 and 25"

[Mining4air]

I have a used home made flow bench I recently purchased that came with a homemade calibration plate. A buddie of mine that works in a bigger shop recently sent me one of Superflows single point plates. The one with the 1.874 hole and the .312 hole in it. I was wondering if any of you guys use these to calibrate your benchs, and if so, what kind of flow do you get at 10" and 25" or 28" when flowing just the big hole with the small one pluged, and with both holes open. As soon as money permits I want to get 3 or 4 plates made, but for now I'm just hoping to get a better idea of how acurate my ranges are.

Thanks in advance.
Jay

[SBC]

SuperFlows' book states with both holes open at 25" on range4/5 ( bench model dependent) it should flow near 238. It does not on my 600.

[Mining4air]

The reason I wonder is I have heads that I have flowed on a 600 that I basically used to calibrate the ranges on this bench after I made a few mods to it, and when I flow just the large hole on this plate i come up with about 254 and about 266 with both open when flowing at 25". The buddy who sent it to me has a 600 where he works and didn't run it across his bench before sending it to me. I got it because they bought a complete set of calibration plates, and no longer used it.

[DaveMcLain]

In the case of the Superflow 110, the test orfice plate that comes with the machine should flow 153.2cfm at 10 inches of depression in the intake direction with both hole open and 3.5 to 5.5 cfm with the big hole plugged and only the small hole open.

This is according to the Performance Trends Port Flow Analyzer book in the section where you calculate a correction factor for a Superflow 110 bench. After doing this correction the flow numbers on heads flow tested on my bench correlate almost EXACTLY with the numbers quoted in the Edelbrock and AFR catalogs for a given head casting. Even when testing at 10 inches and converting the numbers to 28 inch flow. Brodix is completely out to lunch. My correction factor on my bench is 8.4% so my bech was conservative by approx. that amount..

My bench also measures very very close to the numbers created on friends' Superflow 600 benches.

[SBC]

I have a late 90s sf110 book that states 78% scale reading is what the plate should flow on a 110 ( with no reference to 153.2).

[larrycavan]

[SBC]

The earlier 110 books instructed one to "correct too" 153.2 or 78%.

Mr. Bettes informed me the plate sent with my 600 was a "test load" not a "calibration device".

I have two of their plates and can barely see a difference.

Jere Stahl made a brief comment near the end of his speedtalk interview about flow benches and intake ports that made me sit up and take notice.

[Mining4air]

I'm thinking its time to just get some plates made. Like they say, it takes money to make money.

[larrycavan]

[DaveMcLain]

I think that the calibration factor stuff has been a can of worms for Superflow for a long time because when the bench was orginally built the purpose was to compare flow from either one head to another or one modification to another all the while using the same flowbench, depression etc. If it read 5% better or worse, it was 5% better or worse whatever the actual number produced was(within reason of course) didn't matter much. It was not particularly important if some benches read a bit higher or lower than others because the results produced by them would never be directly compared or at least that was the thought. What I've found is that with a little work the benches can generally be made to read pretty close to one another certainly within a few % and that's probably close enough. About the same variance as most dynos or correction factors that are in use today..