Fixing bad port work...

[bill jones]

-the way I see curtain area is simple.

-a 2.050" valve diameter times 3.1416 (Pi) equals a circumference around the head of the valve that is 6.44 inches long.

-Then take this 6.44" times .400" valve lift equals 2.579SIA (square inches of area), 6.44" times .700" lift equals 4.508SIA etc.
-This would be like if you took a piece of scotch tape, taped to and around the outside of the valve head, measure that tape's SIA.

[cboggs]

Bill,

I'm about to show just how bad at math I am, .

The 3.1416 (pi), .. where does that number come from???

So, .. if I understand this correctly, ..

2.08" valve 2.08*3.1416 =6.534528

6.534528*.400=2.90133 curtian area

Is that right?????????

OK, .. so if I take 2.901*114 cfm = 330cfm.

So a 2.08 valve at .400" could flow 330 cfm ????

Glad I have a computer to do all this stuff, ..

Curtis

[cboggs]

On the extra flow box.

Larry yes that's what I'm going to do, .. just a box with extra motors
on the side.

I now see the problem, .. the vertical manometer is easy, .. it's the
inclined. But I think you hit on it with the fluid. Dewyr makes different
fluid to change the scales, .. perhaps this is a question for them.

What is the pressure differential we need to measure?????????

Or maybe some one on this site would know, ..
http://tractorsport.com/cgi-bin/forum/c ... nboard.cgi

So I would think we'd have to put the second inclined in with
some type of valve system so it works only when running the
high pressure rig.

Curtis

[bill jones]

-I have no idea what the asterixs purpose is in your equations.
-but the answers look right to me.
-Pi came from centuries ago when people were really smart.
--------------------------------------
-Just because the curtain area is some good number doesn't mean much if there's a chamber shroud wall within .100" of that valve edge for 40% of the valve diameter.

[cboggs]

-I have no idea what the asterixs purpose is in your equations.
-but the answers look right to me.
-Pi came from centuries ago when people were really smart.
--------------------------------------
-Just because the curtain area is some good number doesn't mean much if there's a chamber shroud wall within .100" of that valve edge for 40% of the valve diameter.

Pi came from smart people, .. ahh, I understand.

Well the reason behind this is a theoretical maximum flow for a valve
at a lift. If we take all the other "things" chamber, port, etc. out of the
equation, .. what can that curtain area flow.

For whatever that's worth, ..

Thanks,

Curtis

[Rick360]

you've probably checked for leaks or leakage, especially when flowing at higher test pressures at lower lifts the exhaust valve can partially be sucked opened at high test pressures

Larry, That got me the first time flowing up at 40". Leak checked ok and then the ex valve started pulling open a little as the intake flow got higher. I got stiffer springs.

also planned to make cable controlled ducting valves to duct hot air to outside of Shop to get rid of the extra increased heat out of the FlowBench room

This time of year I like to keep that heat inside. lol

I now see the problem, .. the vertical manometer is easy, .. it's the
inclined. But I think you hit on it with the fluid. Dewyr makes different
fluid to change the scales, .. perhaps this is a question for them

Curtis, If you know the S.G. of the fluid in the inclined manometer now and change to something different you can calculate new ranges for your bench from the square root of the ratio between the before and after S.G.

example: Using red .826sg fluid and range is 351.4cfm. Change to blue 1.91sg fluid in inclined manometer. This will increase the pressure range of the manometer by 1.91/.826 = 2.31 times its previous range. Increasing the orifice d.p. will increase the velocity inside the bench and may not be able to handle those velocities.

In theory you use...
new range = 351.4 x (1.91/.826)^.5 = 534.35
This range will be adjusted when flowing at higher pressures as you normally do.

I think that flowing at the high depressions is useful, especially after seeing these bowties "back-up" only when tested high enough. Pulling 50" or 60", or more, starts using very large amounts of power when you have a lot of flow. As the pressure drop goes up so does the flow causing an exponential increase in motor power requirements. Can get very expensive real quick trying to get high enough test pressures.

Rick

[cboggs]

Curtis, If you know the S.G. of the fluid in the inclined manometer now and change to something different you can calculate new ranges for your bench from the square root of the ratio between the before and after S.G.
Rick

Hi Rick,

For calculating the range with different fluid, .. please reference my above post regarding my math skills, .. or lack of.

Ok, .. kidding aside, .. yes I think you're right. So the key is to find
the proper fluid with the SG needed to get the range. Dyewr only offers
two fluids that I know of, .. and I think the sf-600 used the heavier
of the two.

Curtis

[Rick360]

the width of the short turn was as wide as the valve od or at least 2.050 i'd have to look at my notes

I have widened these quite a bit at the short turn and is now 1.70" wide at top of short turn. Is that 2.050" correct? I don't think I have the nerves to grind that much more out. From the throat on up into bowl and over the turn it is never as wide as the 1.86" at the throat.

Thanks,
Rick

[bunner engines]

for you guys wanting to add motors to your bench , i would go with the AMETEX brand . with the AUTO THERMAL PROTECTION ! the ones we used was part # 116457 bought right out of the grainger catalog . they where 104 c.f.m each and have never had to replace them in ten years . superflow didnt use these self cooling motors (why i dont know ) but if i try to to a long duration test with the 600 bench it will thermal overload and shut down ! so when we built a new bench using the self cooling motors , problem was solved .

[maxracesoftware]

I have widened these quite a bit at the short turn and is now 1.70" wide at top of short turn. Is that 2.050" correct? I don't think I have the nerves to grind that much more out. From the throat on up into bowl and over the turn it is never as wide as the 1.86" at the throat.

Thanks,
Rick

Hey Rick360...stop grinding !!!

yes the 2.050 ST-Width is correct for a 2.085 OD Valve
but not exactly across from the headbolt tube hole/sleeve

the 2.050 was "before and after" the exposed .502" sleeve
and exactly at the exposed sleeve OD -to- the wall across is = 1.940"

also exactly across from the HeadBolt Tube or Pressed-in Sleeve
is a casting parting line on the waterjacket side

..so depending upon core shift or how deep that parting line is..will set the limit of the Short Turn width you can achieve

1.940" should be considered the max width exactly at that point
1.900" would be safer...but don't attempt this without looking and measuring a sectioned-piece of Head as breaking into the waterjacket is very close and so is ruining the head !!


your 2.055 valve times .90% PerCent = 1.850
i'd stop at the width you are now !!!

take it easy, work slow and very careful when porting till you gain a lot experience with that casting !! Don't get greedy for that few extra CFM of Flow..keep it safe .


you have to have a variety of homemade very accurate tools to measure
thicknesses like that , along with very accurate templates or CNC program ...all that should be double-checked against a Band-sawed sectioned casting as a referrence !!!

[ozrace]

for you guys wanting to add motors to your bench , i would go with the AMETEX brand . with the AUTO THERMAL PROTECTION ! the ones we used was part # 116457 bought right out of the grainger catalog . they where 104 c.f.m each and have never had to replace them in ten years . superflow didnt use these self cooling motors (why i dont know ) but if i try to to a long duration test with the 600 bench it will thermal overload and shut down ! so when we built a new bench using the self cooling motors , problem was solved .

All Ametek Thru-Flow Discharge motors are self cooling, in that the air flow passes through the motors. (they don't all have thermal protection)
The problem with the way they are used in a Superflow bench is that all the motors are running at all times - so at low flow (low lift), there is not enough air passing through the motors to cool them and they burn out.
The solution is to fit a Flowcom unit with motor control, or one of Audie's Depression Control units. Either of these will make testing quicker and easier, and extend the life of the motors many times over.

[ozrace]

On the extra flow box.
Larry yes that's what I'm going to do, .. just a box with extra motors
on the side.
I now see the problem, .. the vertical manometer is easy, .. it's the
inclined. But I think you hit on it with the fluid. Dewyr makes different
fluid to change the scales, .. perhaps this is a question for them.
What is the pressure differential we need to measure?????????
Or maybe some one on this site would know, ..
http://tractorsport.com/cgi-bin/forum/c ... nboard.cgi
So I would think we'd have to put the second inclined in with
some type of valve system so it works only when running the
high pressure rig.
Curtis

Curtis, bolting on extra motors will be the easy part. Coming up with a way to determine c.f.m. above that available from the standard incline manometer will not be so easy.
The Superflow method of measuring airflow doesn't use any accepted "Standard" i.e. it is essentially their own method. The standards available for flow measurement with orifices are based on flow through a tube.
So on a Superflow, the manometer calibration and flow charts are determined at the factory by comparison with known results. That's why they are unaffected by weather conditions - they are like a comparator with a lookup table.

Also, you will reach the point where the bench will need extra holes on the internal orifice plate. i.e. more than 6 ranges.

[cboggs]

Gang,

Just found this, ..

differnt indicating fluids for the inclined manometers, . .
http://www.meriam.com/products/default. ... &d=84&p=40

Any other ideas for the bench expansion?

Curtis

[cboggs]

OZ,

For sake of discussion, .. if we take a SF-600 flowing a big block head
that flows 500 @ 28", .. at say 48" we will still have range on the inclined won't we? The problem is the bench doesn't have the vacume capacity, ..

So, .. couldn't we just convert those numbers back to a 28" number
to compare?

Now I know we've been discussion test depressions much greater then
48", .. ..

I'm having a senior moment here, ..

Curtis

[Rick360]

For sake of discussion, .. if we take a SF-600 flowing a big block head
that flows 500 @ 28", .. at say 48" we will still have range on the inclined won't we? The problem is the bench doesn't have the vacume capacity, ..

So, .. couldn't we just convert those numbers back to a 28" number
to compare?

When that port is flowed at 48" it will flow 654.7 @ 48". Do you have a range that goes that high? The full scale ranges will also be reduced slightly at higher depressions. Both capacity and ranges can be a problem, depending on what heads you're flowing and how much vacuum you want/need.

Hey Rick360...stop grinding !!! Smile

Are you supposed to see thru the walls into the next port? lol

I am not into the bolt hole but close. ~1.80 now. I am done enlarging and am trying to fine tune the short turn and valve back angles. They are already flowing much better at 40" than they did.

Thanks,
Rick