Wooden Greenhouse Build

Menu


Categories


Archive

Air Flow Bench Plans,Sketchup Woodworking Cutlist,Loft Bed With Desk Plans,woodworking optimization software - Tips For You

31.03.2015 admin
You can see that this bench primarily tells us whether or not the port is flowing better or worse.
At this point, you may be thinking that not having the ability to determine the CFM is a small price to be paid to establish positive or negative trends in a head’s airflow capability.
Over the next few years, I built increasingly more sophisticated benches until finally, during the early 1970s, I built a bench that conformed to British Standards for precision gas flow measurement. All the forgoing leads to one conclusion: To more nearly simulate what happens in a running engine, intake flow tests need to be done at a high pressure drop at low valve lift and a lower one at high lift.
If the pressure drop is too low, the flow pattern that develops in the port, especially in the more critical regions close to the valve seat, is not the same as at the higher pressure drop seen in a running engine. When these conditions exist, air is fed to the part of the valve circumference that is situated adjacent to the short-side turn, so that the flow is better than it typically is at a higher pressure drop.
If we take a low standard pressure drop test of, say, 8 inches and correct it to 28, the resulting number comes out higher than if we had flow tested at 28 inches in the first place. Running the flow bench tests and conducting high-to-low floating pressure-drop tests creates the same pattern of flow-reducing portto-wall separations that occur during real-world running conditions. The bottom line is that our cheapo flow-test setup is actually a better tool for developing an intake port than a $10,000 commercial flow bench used in a conventional manner. Without making some fancier test equipment, we are not going to be able to flow the exhaust at reallife test pressures. However, our budget bench, with its uncontrolled floating pressure drop, actually does a better job than a commercial bench at a fixed pressure drop.
When using my early flow bench, I never made the connection between using a floating pressure drop and actually calibrating the setup to give CFM. What really caught my attention was the calibration plate Roger had made and the graph he was using to simply read off the CFM at 28 inches of depression.
A few words about producing or acquiring a Helgesen plate: With Roger’s kind permission I have reproduced the dimensions here, so you can make your own. Step 1: Make sure your bench is sealed so no leakage takes place, except through the test piece.
Step 2: Start with a reading on the manometer, with the plate completely blocked off for a “zero flow” depression test, and note the pressure drop seen on the manometer. Step 3: Open the 5-cfm orifice and note the depression (when I was talking about machining this plate they were referred to as holes—now that we are flowing through them they are orifices).
Step 7: When you have a curve for the intake, repeat the test but use the blower side of the vacuum cleaner and reverse the plate. You can now flow a head and get some respectably accurate flow figures for comparative purposes. Although what we have done here is very basic, it can produce results comparable to benches costing $10,000 or more and considered the industry’s standard. The voltage input to the motor influences the amount of suction a vacuum cleaner or any electric air mover can produce. Big changes in temperature and pressure also affect the reading, but this is only minor if the bench is in a constant indoor temperature.
If you have built a bench along the lines I’ve suggested, then at this point, you have a bench that was cheap to build and can deliver CFM numbers. Let’s look at how to take the floating depression bench just described, and substantially upgrade it to a professional-grade piece of test equipment. If we further analyze the performance equation, we find that at least 70 percent of a cylinder head’s performance capability is airflow related. You don’t have to tour many head shops to realize the most popular bench used by pros is the SuperFlow 600—possibly with electronic support. Although overall accuracy is important for us to make comparisons from different benches, the number-one requirement for a head porter is consistency from one month to another.
At this point our tests turned to determining just how well, given the floating pressure drop, the Flow Quik’s performance translated into accurate and repeatable results on a real head. To put the Flow Quik through its paces, we used a Holley 23-degree, high-performance street small-block Chevy head.
Although installing the test head on this bench was the same as with any other bench, there was a difference from, say, a SuperFlow bench: The Flow Quik does not directly sense and compensate for any extraneous leakage. The last and, from our point of view, the most important test was to run the Flow Quik with a regular shop vac.
Our first thoughts on the performance of the Audie Technology Flow Quik were that it far surpassed expectations.
Performance Trends offers a couple of options for the DIY flow-bench builder: Port Flow Analyzer software and Black Box II electronics.
Performance Trends also offers calibration services for a small charge; you simply provide them flow readings from your bench with orifice plates of various sizes.
For those who want to start building a bench from scratch, Performance Trends offers a system called EZ Flow for about $999.
The EZ Flow system also includes critical machined components, the flow orifice, and the head adapter. After building my British Standards compliant monster bench and using it for several years, I moved from the UK to Tucson, Arizona. In 1976, the publisher I was writing for acquired an SF 300, which is the big bench that evolved into the SF 600. Our PWM Valves connect to our FP1 Electronic Flow Rate Processor to control air pressure to a preset value.
Cylinder bore adaptors simulate the cylinder of an internal combustion engine for cylinder head flow testing on a flow bench. Flow Performance flow bench kits are a perfect core for building a high performance, high power professional flow bench.
A flowbench measures the air flow volume or mass that is flowing through objects such as internal engine parts.
A flowbench can measure the air flow capacity of an automotive cylinder head, and many other items.
This is a demo of a big-block Ford head being tested on the FP2.0BS flow bench, in stock form, then after some mild porting and valve work.


A larger, more powerful air supply can also be used with this kit for real cfm data at high test pressures.
It was connected to a manometer, made of clear plastic tubing stapled to a 2 x 4-inch board. Also we can see that it does not test the head at a standard pressure drop, as does almost every pro-built bench. After having built my bench, I spent a couple of years wondering how I could get real CFM numbers off it, so I could swap flow bench war stories with the guys at Weslake (the big name in airflow at the time) with-out revealing both my youth and then-amateur status. If we use a pressure drop that is too low, the flow attaches itself to the port wall on critical curves, such as the short-side turn, without any significant flow separation. When the pressure drop is increased to something more nearly representing that seen in a running engine, the port velocity increases to the point where the air simply skips off the short-side turn and tries to exit the valve on the long side. In practice, if pressure drops significantly below 8 inches are used, the flow in the port slows enough to stay attached even around a relatively tight turn. From this, it follows that the most effective port modifications are achieved by addressing real-world flow patterns and improving the port shape to improve such patterns.
At this point, the only down side is determining just how many CFM the head is flowing when each reading is corrected to the common 28-inch pressure drop.
I can say that there is little to prevent using a commercial fixed-pressure drop bench, such as the SuperFlow 600, in a floating pressure-drop mode, which I address in Chapter 3. Air” Helgesen built a bench that worked along the same lines as this in the early 1980s and still uses it today to flow heads and intake manifolds. While this may allow you to establish whether a move has increased or decreased airflow, it does not, at this time, allow you to compare your efforts with the rest of the head porting community.
Instead, I invested a lot of hours building my monster British Standards bench with all the corrections then known to man.
Position the Helgesen plate on the bench with all holes plugged with clay (or any convenient plugs). For the numbers to stand even a halfway decent chance of being accurate, the bench must not leak at any point. The ideal situation is to mount a box, which can be made of wood but must be airtight, about 9 inches down each side (9 x 9 x 9) with a 5-inch hole in the top, and whatever size hole mates up to the block or whatever you are using to simulate a block.
If there is any doubt about the figures, recheck the depression with the plate at, say, 160 cfm. This includes an electronic readout in CFM, pre-corrected to the depression of your choice (probably 28 inches), and that alone might convince most of you wanting a more up-market bench to take the plunge. If you hook up your bench to a computer, you can record data with a push-to-read button that, while held down, averages the readings for as long as you do so.
This puts a greater emphasis on even small flow differences; and if you want to win, it’s important that whatever you have is better than whatever your competition has. You probably also understand the reason you don’t have one of these benches is because it can cost as much or more than the race car you are planning to build. This company produces, among many other things, the Flow Pro data acquisition unit that is an add-on for non-computersupported benches such as the big SuperFlow units. To do this, we ran the bench both ways and used our Helgesen calibration plate as the test piece. This pushed the Flow Quik to what we perceived to be about 80 percent of its limit with a dual motor-vacuum source.
Since the point was to see if a typical vacuum cleaner could be used, it was not part of the plan to get the biggest one we could find.
In fact, SuperFlow resells Port Flow Analyzer software, Pitot tubes, swirl meter, and other accessories with its flow benches. These can be fitted to almost any type of DIY bench, even older SuperFlow, JKM, and FlowData benches.
Using this data, they tell you the full-scale CFM readings for your particular bench; so your bench, with their software, now matches the rest of the industry. This kit includes software and electronics, and plans for building a bench from PVC tubing. Flow Performance products utilize the power of personal computers, the Internet and email to provide powerful air flow measurement, analysis and control. While using a shop vacuum to move air through the flow bench, the FP1 processor estimates the flow data to 28"wc test pressure, in real time, as the flow test is being performed.
While the real test pressure is quite low using a shop vacuum, the FP1 processor estimates the flow data to 28"wc test pressure, in real time, as the flow test is being performed. At low valve lift, say, 0.050, the manometer can read (depending on the vacuum cleaner’s capability and the valve’s ability to flow air) anywhere between 60 and about 100 inches H2O. This standard pressure drop, as previously stated, is considered conventional practice and allows a uniform method to be used for quoting the CFM of flow produced.
It worked just fine and cost a small fortune but the payoff was a lot of flow work that was done for those porters who didn’t have a bench.
As a result, a considerable section of the intake valve’s circumference experiences very little flow. Without this number, you won’t be able to make a comparison with other flow test results or be able to compare your work to others. For many years, I knew Roger Helgesen had a flow bench but the deal was we always hung out at my place (maybe that’s because the Serdi seat and guide machine was there).
It has holes sized to flow 5, 10, 20, 40, 80, and 160 cfm at 28 inches of depression across the plate.
Just how much is dependent on how severe any flow separation on the short-side turn is at the higher pressure-drop readings I am advising you to use. I have written a relatively simple Microsoft Excel program that allows me to input the depression numbers into my computer and subsequently prints a  professional-looking set of graphs of  the flow tests, complete with my business details along the top of the paper. Nor, without considerable programming yourself, does it produce an analysis of what has been achieved such as flow efficiencies, port velocity, velocity gradients, and the like. So, for most racers and enthusiast engine builders, a $10,000 to $15,000 bench is simply out of the question. It also produces the cost-conscious Flow Quik, which sells for about $750, and is not a flow bench in itself but more a means of measuring flow.


A comparison of our Helgesen plate, flow tested on the floating depression method as used by our budget bench in conjunction with the Audie Technology Flow Quik unit. For the tests done here, a Helgesen plate (left) was used as a reference to test the Flow Quik’s overall accuracy. In the floating mode, the test pressures seen on the bench by the Flow Quik ranged from about 72 inches to less than 10.
In this instance, the unit was calibrated with the 80-cfm orifice in our Helgesen calibration plate, hence the zero error at that point.
Readings taken seven days apart showed the Flow Quik’s repeatability to be about 1 percent.
The curves starting high on the left and dropping toward the right show the test depression used for each of the two flow tests.
The Performance Trends EZ Flow system comes complete with drawings for the basic components the end user needs to source. If you are building a bench that can top 400 cfm at 28 inches, you should seriously consider building the 6-inch EZ Flow unit. One of the great advantages of buying a commercially available electronics package for what is essentially a home-built bench is that you get very useful software to support the system in terms of not only data acquisition but also data analysis.
The head adapter for the 6-inch EZ Flow allows for easy replacement of the head-bolt adapter plate and bore sleeve.
I had used a small 110 for accuracy comparison to my home-built bench while still living in the UK.
Combine this with the fact it comes equipped with the Audie Technology flow measuring gear and software, and you get a bench that delivers results in a standard form while measuring with a sliding scale (floating) pressure drop—all good for doing the job right. Looking back on it many years later, I realized I should have continued flowing heads using this original method, instead of being swayed by convention.
They build some of England’s swiftest Mini Coopers, and it all starts here on the flow bench. The plastic tubing was looped, so that the bottom of the “U” was formed about a couple of feet or so below the bottom of the 8-foot-long 2 x 4. Not only can you use this plate to figure out how much flow is passing through a head on a floating depression bench, but you can also use it as a reference tool for a regular bench, such as a Superflow.
Air has a step-up transformer that increases the line voltage from whatever it may be (it varies between 110 and 115) to 130 volts, and then a rheostat device is used to adjust it to 115 volts.
If the plate is mounted on top of a bore even as large as 4 inches, there is a residual effect from the downstream velocity of the air and the plate flows about 2 to 3 percent higher than if flowed into an open box.
You might guess this Sears 2?-hp, 6-gallon unit cleans but cannot flow a head; but with a floating pressure drop, this unit got the job done in spite of its marginal power.
By adding this unit to an existing flow bench, we can achieve as much as can be done with a commercial flow bench but at a fraction of the cost.
To expedite matters, Audie Thomas of Audie Technology shipped us the Flow Quik unit the company exhibits at the Performance Racing Industry show. It produces creditably accurate numbers in this mode; and in terms of accuracy, compares well to fixed-depression tests done on a Super Flow 600. As far as overall accuracy, it is far better than the majority of benches in the performance world.
At the end of the day, we can say that the Flow Quik’s accuracy against a calibration plate was as good as a bench costing ten times as much.
Also a push-to-read or take-reading button can be used to transfer the measured CFM to a Flow Quik program. And because the test depression goes so much higher than on a regular bench, the springs holding the valves closed must be at least twice the stiffness. Regardless of the big difference between the red and green test depression curves, the Flow Quik still corrected the flow numbers to generate the nearly identical red and green flow curves seen here. Add to this the cost of building the bench as detailed earlier, a dial gauge, and a means of opening valves, and you are in business. This leaves only items such as the PVC piping to be sourced to complete the parts list required for a finished bench. This screen shows the repeatability of the EZ Flow system and also makes a comparison with the readout from a typical Super Flow 110 bench. This means you can quickly change your bench to flow different-style heads and engine bores in minutes. The only difference between what I do on this bench and what most others do is that I use a sliding scale of pressure drop, the same floating pressure drop I described earlier in this chapter. Although unconfirmed, I have heard that Ford’s Detroit division has a flow bench that can approach real-world pressure drops, and that it costs a mere seven-figure number to build.
Doing otherwise means investing what is potentially a huge amount of time, effort, and money in a bench that, at the end of the day, serves you less effectively than  the  super-cheap  floating-pressure-drop  one I advocate here. It allows your bench to read out in corrected CFM and directly integrate with your computer, so you can do fancy printouts. The bottom line: Our test Flow Quik unit produced figures (which could be expected to vary a little from unit to unit) that are closer than typically measured between two conventional and supposedly identical fixed-depression benches. If the shop-vac selected is about 6 hp, like a big Sears unit, I estimate a realistically accurate range of flow capability of about 330 cfm. Unless multiple layers of paint are applied, significant amounts of air can leak right through plywood if enough care is not taken during prep and assembly. For the most part, we flow the exhaust at 28 inches and live with the fact that it is not the best way to do things. However, if you want a little more than just a vacuumcleaner-powered bench for a greater range of pressure drop,  by all means build it with more powerful motors. Think about this: You can have a professional-capability floatingdepression bench for under $750. This means the flow has gone up, so the pressure drop pulled by the vacuum cleaner is lower.




Short Wood Retaining Wall Ideas
Used Combination Woodworking Machines For Sale

Rubric: Payment Plans For Furniture



Comments

  1. ANILSE writes:
    Tool inventory by adding to it with wolf was able to blow down their houses with.
  2. Dj_POLINA writes:
    Woodworking Instruments and Their Uses in Woodworking Projects Woodworking outlined.
  3. aci_hayat writes:
    Cowl a broad range of possibilities Air Flow Bench Plans although, so it is certainly worth having from Taunton Press's vast cache of tasks and.