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Superflow 110

instructions section 1.0

Flow-testing 1.1 Supi rflow 110 de icriptlon

1.5 1.6 1.7 L.8 2.0

page

ting heads f ir testing test prelit .naries • test Per Tes data sheet ample Analyzing the te: t data Avoiding

Air Flow Through Engines

1 2 2 3 4 6 8 9 10

3.0 HP & RPM & CID & CFM

12

4.0

Intake Port Area & Shape

16

5.0

Valve Seats

18

6.0

Valve Sizes

18

7.0

Valve Lift & Flow

19

8.0

Combustion Chambers

22

9.0

Dynamic Flow Effects

23

10.0

Inertia - Supercharge Effect

24

11.0

Test Pressure Conversion Chart

26

12.0

Suggested Additional References

27

1.0 Flow-testing 1.1

Superflow 110 description The Superflow 110 is designed to measure the air-flow resistance of engine cylinder heads, intake manifolds, velocity stacks, and restrictor plates. For intake testing, air is drawn in through the cylinder head into the machine, through the air blower, and exits through the orifice plate at the top of the Superflow 110. Forexhaust testing, the path of the air-flow is reversed by a switch on the front control panel.

The test pressure meter (manometer) measures the pressure or vacuum at the base of the test cylinder. The test pressure is adjusted to a standard value, for instance 15.0 inches of water, by turning the flow control knob on the lower front panel. Separate knobs control either the intake or exhaust flow. The amount of flow is read from the inclined flow meter (manometer). The flow meter measures the pressure difference across the 5 flow orifices at the top of the Superflow 110. By selecting different combinations of orifices, the flow meter can be used in any of 9 different ranges to obtain high accuracy over a wide range of flows. The flow meter reads 0 to 100% of any flow range selected with the rubber stoppers. A separate test orifice with a .312" diameter and a 1.875" diameter hole is included for calibration of the flow tester. The machine requires 110 VAC, or 110 VDC electrical power and draws 15 amps.

1.2

What Is a flow test? In its simplest form, flow testing consists of blowing or sucking air through a cylinder head at a constant pressure. Then the flow rate is measured at various valve lifts. A change can be made and the head re-tested. Greater air flow indicates an improvement . If the tests are made under the same conditions, no corrections for atmospheric conditions or machine variations are required. The results may be compared directly. At the other extreme, it is possible to adjust and correct for all variations so that test results may be compared to those of any other head, tested under any conditions on any other Superflow machine. Further calculations can be made to determine valve efficiency and various recommended port lengths and cam timing. •• The calculations are very cumbersome without a small.electronic calculator, preferably with a square root key. The calculations are not essential to simple flow testing.

1.3

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:

Adapting heads for testing Cylinder heads are mounted onto the Superflow by means of cylinder adaptors. The adaptor consists of a tube 4" long with the same bore as the engine and a flange welded on each end. The lower flange is bolted to the flow tester and the upper flange is bolted or clamped to the test cylinder head. The flanges must be flat or gasketed to make an airtight seal. The adaptor tube may be 1/16" larger or smaller than the actual engine cylinder. In some cases it is convenient to make the upper flange of the adaptor about 20% wider than the test cylinder head so that the head will be supported when it is offset for testing the end cylinders.

. .

A device must be attached to the cylinder head to open the valves to the various test positions. The usual method is to attach a threaded mount to a rocker arm stud so that the end of a bolt contacts the end of the valve stem. As the bolt is rotated, it pushes open the valve. A 0 to 1" x .001 dial indicator may be mounted to the same fixture with its tip contacting the valve spring retainer to measure the amount of valve opening. The standard valve springs should be replaced with light springs for testing. See the photos in the Superflow brochure for various types of valve openers. On the intake side of the cylinder head, it is strongly recommended that a radiused entrance guide be installed to lead the air straight into the head. The guide should be about one port width in thickness and be generously radiused on the inside all the way down to the head. The intake manifold can also be used. The exhaust flow may exit directly from the head.

1.4

Flow test preliminaries All test data may be recorded on the standard Superflow form F-120 test data sheet, (see sample). Before beginning a test, record the head description, and measure the stem and valve diameters. The net valve area is the valve area minus the stem area in square inches. net valve area = .785 (D 2

-

D2

)

Before installing the test adapter, install only the staritiard test orifice plate onto the Superflov. Install all the rubber stoppers in the orifice plate on top of the Superflow and set the direction knob to Intake. Close the intake and exhaust flow control knobs lightly against their seats. Zero the vertical test pressure meter and level and zero the inclined flow meter. With only the small .312" diameter test orifice open, turn on the machine and slowly open the intake flow control until the test pressure reaches 10.0" of water. The flow meter should now read approximately 45% on the 10.0 cfm range (#1 orifice open on top). This indicates a flow of .45 x 10 cfm = 4.5 cfm. If flow is within 1 cfm of this reading, the machine is working properly. Now remove all the rubber stoppers from the top orifice plate (185 cfm range) and open both the .312" and the 1.875" diameter holes in the test orifice. Adjust the intake flow control again until the test pressure reads 10.0". Allow the machine to warm up for several minutes until the upper thermometer reads about 25°F higher than the lower thermometer. Multiply the flow meter reading times 185 cfm to obtain the test orifice flow. It will be 153.2 cfm under standard conditions. If the flow meter does not read 153.2 cfm, the flow readings will all have to be corrected by a correction factor. This factor is equal to: Test flow correction factor -

153.2 test orifice flow

This factor compensates for machine variations and all atmospheric conditions. Enter this information on the test data sheet. For best accuracy, this factor should be determined before each day's testing. It does not need to be re-determined before additional tests on the same day. Multiply the flow ranges on line C by the correction factor to obtain the corrected range, and enter these in line D on the data sheet. The corrected flow ranges may be used for all tests made on the same day. If Superflow will not draw 10" due to low line voltage, use 8" test pressure. Then: Flow correction factor -

t e s t O rijice

flow

All tests should be performed at the same ratio of valve lift to valve diameter, or L/D ratio. Then the flow efficiencies of any valves can be compared, regardless of size. Multiply the valve diameter by each of the six L/D ratios to obtain the valve lift test points. Fill these in on lines A and B of the data sheet. Choose the proper test pressure for the intake valve diameter the exhaust valve at the same test pressure. in on line 3 of the data sheet. Valve diameter 2.1" to 2.3" 1.6" to 2.05" less than 1.6

Fill the test pressure

Test pressure 5" 10" 15"

This completes all the preliminary preparations. While they are very time consuming, they will insure that the test results are valid and repeatable. Most of the preliminaries will not be required for subsequent tests of the same head. .. . . 1.5

Performing a flow test

'

f

Remove the test orifice plate from the machine and install the test head, cylinder adapter, and valve opener onto the flow tester for the actual flow tests. Set the dial indicator to read 0 with the valve closed. Install either the intake manifold or an air inlet guide on the intake port.

inclined flow meter. Close the intake and exhaust flow control valves lightly against their seats (do not force or they will be damaged). Place the rubber stoppers into orifices 5, 4, 3 and 2. Turn the mode selector switch to intake. Turn on the Superflow and adjust the intake flow control until the test pressure meter reads the test pressure you intend to use. Determine the leakage flow from the flowmeter and chart. Because only the #1 orifice is open, the flow meter reads L0 cfm at 100%. A reading of 47% would indicate a leakage flow of .47 x 10 cfm « 4.7 cfm. Leakage will usually be from 1 to 10 cfm. If there is no leakage, the test pressure may rise to the top of the meter. This does not matter as long as the flow meter reads zero. The leakage wilL not affect the test provided that you correct for it in your results. Turn off the Superflow, Repeat this test before the exhaust tests. Enter the leakage on line 8 of the data sheet to be subtracted from the chart cfm. Open the valve in the head to a lift of .20 valve diameter. Remove all four rubber stoppers from the flow orifices and turn on the Superflow. Adjust the flow test pressure to 10.0" and allow the machine to warm up for 5 minutes. This step may be omitted if the Superflow has been warmed up previously.

The flowmeter is designed with multiple ranges so that the flow can be measured very accurately. For greatest accuracy, use only the orifice ranges which give readings above 70% of the scale. If the reading exceeds 100%, switch to the next higher range shown on the flow chart by changing the combination of orifices open at the top of the Superflow. If you have previously determined the proper flow ranges, fill in line 5 and skip the next step. If not, open the valve to the first of the six lift points. To select the proper flow range, begin with the largest stopper and re-install the stoppers in the flow orifices until the flow meter reads above 70%. This is the proper number of orifices for this test pressure, head, and valve lift. Always use the same combination for future tests at this point. From the chart on the front of the machine, determine the full scale range value, then record the corresponding corrected flow range from line D on line 5. Re-adjust the test pressure to the recommended value and record the readings of the flowmeter and the temperature difference between the top and bottom thermometers onto the Superflow F-120 data sheet. Turn off the machine. Go to the next valve lift and repeat the above steps. (Each valve lift may require a different flowmeter range.) Continue this procedure until you have reached the maximum lift test point.

and close the intake flow control valve. Move the valve opener and dial indicator to the exhaust valve and repeat the above procedures. This completes the test. — . For intake manifold tests, remove the radiused inlet air guide and replace it with the intake manifold. Repeat the intake tests and compare the results to determine the effect of the intake

TEST

DATA

SHEET

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