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 A "floating pressure drop" type flowbench - By David Vizard 
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Joined: Mon Apr 05, 2010 9:18 am
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http://www.gofastnews.com/showthread.ph ... Flow-Bench


Mon Apr 05, 2010 10:25 am
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A vaguely recall a discussion about that article a while back. As I see it, there are some fundamental problems with that approach, the biggest one being lack of repeatability . In order to get consistent test results from run to run you're relying entirely on the performance characteristics of your vacuum source being consistent from run to run.


Mon Apr 05, 2010 9:01 pm
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Here is an 8 page thread on the old forum about this subject: Floating Depression Bench

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Mon Apr 05, 2010 9:43 pm
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Location: Maryland
Sully,

The article from Vizard is a ripoff from the book Practical Gas Flow by Dalton.

http://www.amazon.com/gp/product/1855205645/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=0947981330&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1RHPAG1VZB1AV7W2GW66

The basic disign is on the premis of % improvement with alot of assumptions, if you read daltons book you will understand its place in DIY home tuning and also learn somthing on basic porting.

Rick


Tue Apr 06, 2010 4:34 pm
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Joined: Thu Feb 25, 2010 3:39 pm
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1960FL wrote:
Sully,

The article from Vizard is a ripoff from the book Practical Gas Flow by Dalton.

http://www.amazon.com/gp/product/1855205645/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=0947981330&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1RHPAG1VZB1AV7W2GW66

The basic disign is on the premis of % improvement with alot of assumptions, if you read daltons book you will understand its place in DIY home tuning and also learn somthing on basic porting.

Rick


I when back and re read that 8 page thread again............. it was a Good One!!! Sad it ended so abruptly...........
But the next step was building and showing its merits, Good or Bad.............and the only one willing to do so........never got back to us :(

when i started on this flow bench Journey, it started at Mr Vizards site.
and i learn a lot there. even built one of them floating, single shop vac benches.........But it was not accurate and didn't want to do all the temp, humidity . Voltage stabilization exc. That stuffs not Cheep(AKA, HOW TO BUILD A FLOW BENCH FOR 35(?)DOLLARS) Well it's a lot more to make it accurate.......

Then i found this site, i built another bench. (I won't call it a pts bench because i didn't fallow the plans in some crucial areas and it cost me a lot of grief(and the pts members as well :roll: :) ) getting to be turbulent free!
You guys were all so pation with me THANK YOU

If i had it all to do over again, it would be the "P.T.S.FLOW BENCH" done by the plans! NOT the so called 35 dollars bench.

Still it would have been nice to see some one, go down that road, of making a floating bench work,.....................

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Fri Apr 09, 2010 4:51 pm
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Let me take a minute to clarify the concept of the floating point bench as many of the Vizard followers have defended ad nozium.

The concept is solely about showing change Good or Bad but in no way can be correlated to CFM. It works like this if I put a vacuum source on the combustion chamber, connect a monometer to the spark plug hole with the intake valve open all the way I should measure some level of vacuum within on the monometer as the intake port flows air. I then adjust my intake valve opening (must be measured accurately) to a point where I read say 2/3rds up my scale lets say 24” lets say the valve is opened .250 Inch. I record all the BS voltage, temperature, humidity, etc.

I then port on my head with my special tools hopping for improvement, I grind on the valve, all that good stuff. When I am all done I hook up my vacuum source, monometer and open the valve to the exact same place in this case .250 Inch open. I turn on my vacuum source and make a reading of my monometer; Lets say it now reads 23” viola I have less restriction  it must be flowing more “Jump up and Down” now I have taken all the reading and voltage and air and humidity are all the same so to simplify this I was at 24 before but now at 23 so 23/24 = .95833 or an improvement of 4.166%.

That it in a nutshell you have just ported some heads and flowed them so you can go bench racing with your friends and tell them about your improvements; Yes I know they made it sound more sexy and scientific but the facts are that porting heads and flowing them is far more in depth than saying I made them flow more. If I had a dollar for every guy out there that wish he could trade some of that flow he measured/got for a few more FPS in the right place I would be rich. If you don’t believe me search the forum and many other racer forums on “Porting Epoxy” there sure are a lot of guys looking to add material ????.

I kind of look at it like this, my girl is 36,30,38 you know I like’em when they can carry there side of the cooler :), she say’s honey I think I am going to lose some weight before summer! I Say baby ok lets go to the gym together, and she say’s no I got this new stuff off the TV that if I take it at bed time I will lose weight while I sleep, ok you go for it I’m going to the gym. A month later she said baby I lost 15Lbs I said that’s great honey how are the clothes fitting? She said “About the same! ??? but I need some new Bra’s ??? :idea: yep she is now a 32,30,38 I said you want to go to McDonalds for Dinner then maybe go get some Ice Cream :P

There are no shortcuts!

Rick


Fri Apr 09, 2010 6:11 pm
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1960FL wrote:
yep she is now a 32,30,38 I said you want to go to McDonalds for Dinner then maybe go get some Ice Cream :P
There are no shortcuts!
Rick


That is really good Rick :lol:

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Fri Apr 09, 2010 6:23 pm
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What a GRATE way to paint a picture :lol: :lol: :lol: ;)

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Sat Apr 10, 2010 1:07 am
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This is great! When I first joined this forum and posted the link to Vizard's article, Bruce warned me that it may kick up a little dust. However, I never dreamed that it might drift over to weight watchers :lol:


Thu Apr 15, 2010 6:38 pm
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sully wrote:
This is great! When I first joined this forum and posted the link to Vizard's article, Bruce warned me that it may kick up a little dust. However, I never dreamed that it might drift over to weight watchers :lol:



Sully,

What I have learned over the years in this business is that there are NO short cuts and simple tricks to magical torque increased throughout the RPM range. No snake oil no special machine no secret part, just tried and true R & D full of self education (and a lot of broken parts) gets you to the top. The internet is full of self proclaimed internal combustion guru’s and then there are those that work at the top of the heap NASCAR, F1, NHRA etc. There not out here selling there secrets telling us how to get there! Yes once in a while one of the Ex employees may hang a carrot or some of the guy’s that work near the top may share some advice but at the end of the day the guy winning on his own is earning respect and the guy working in engine development for a team is looking for that next reliable HP increase, its his JOB and he’s not willing to give up what keeps him employed in some forum on the net. Most of what’s for sale (and can be had for free if you like to read) if understood will take the average box of parts and if assembled correctly make a strong running motor but the facts speak for themselves there are 1000 times the 1.25Hp/CID motors running around than there are the 2.0Hp/CID of the same motor (naturally aspirated).

When I am setting an ultimate goal for my own projects I will run the simulators through the paces I use several Dyno simulators and Pipemax along with programs I have written on my own for calculating dynamic compression etc. I use NASCAR as my goal as these guys with 358CID make 850 HP limited to a 12:1 CR and only 830CFM of airflow now that’s over 2.3 HP/CID Killer and the BUSH guys are making 1.9 with 9:1 and 390 CFM. It blows my mind.

Just ask yourself how many tunnel ram small blocks have you seen at the track running mid 11’s with 1400 CFM or more of carb hanging on top???

The 1969 Chevrolet Camaro Z28. Specifications Wheelbase, inches: 108.1. Weight, lbs: 3765

So giving some space for error and maybe a passenger 4000Lbs and 650Hp is like 10.67 in the ¼ and that’s on 9:1 and 390cfm, kind of makes you scratch your head. Or if we had a Cup motor in there more like 9.80’s WOW who would not love a 9.80’s street trim muscle car that could run 500 miles WFO all under the stock hood.

So as you can imagine every piece of the puzzle is working in harmony. What does all this have to do with variable depression cylinder head testing? It is not some panacea, it is an idea that someone had years ago that new about flow but at the time maybe did not want to or could not convey all the math associated with orifice plates, monometers, Delta P and depression control to the guys at home with a grinding stone and a old electric drill.

It 2010 we have FlowBenchTech.com and the facts are the facts for little money and some scrounging you can build the PTS bench have one hell of a bench and do some real world comparable testing. Yes the PTS bench is now in who knows what generation but as been said from the beginning some junk yard vacuum cleaner motors a Harbor Freight motor controller a couple of Bruce’s plates two yard sticks and some plastic tube and your flowing as accurate as the big blue bench. My money is on it and you will have real numbers to compare to.


So to answer your question “Weight Watchers” what I know is currently I weigh 4 big rocks, two medium rocks and 6 small rocks, but when I get to 5 big rocks my wife said no more Ben and Jerry’s Cherry Garcia! I think that is 3 or 4 more small Rocks but I’m not sure. Yup I don’t own a scale read something on some guy’s weigh loss forum about saving money and using some old wood and a pile of rocks I think his name was Dr. Phil. :D

Rick


Mon Apr 19, 2010 6:30 pm
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