ghetto manometer!

[Captainkirk]

Maybe your not much of a cobbler.

Wrong. My problem is, I'm TOO much of a cobbler. I refuse to accept anything less than professional and perhaps carry it a bit too far. Being a professional mechanic by trade, I expect precision and perfection from others and assume they expect it from me.
The YICS blanking tool I built for my '81 Seca is nothing short of professional. In fact, I've sold several of them to others and received high praise for them.
The remote fuel tank I built is probably better than the one sold by Motion Pro. In fact, I'd bet my paycheck on it.
You all are quite correct in assuming a home-brewed apparatus will suffice for the occasional home tuner working on his own machine. My point was, when people are paying you to work on their machines, they expect a little more than aquarium tubing and tranny fluid, and quality and precision is not that expensive at under 100 bucks. A couple of carb synchs for friends and aquaintances will easily pay for a good set of carb sticks, with a ColorTune thrown in, to boot. However, I don't want to hijack your thread, so I'll bow out quietly and leave you all to it.
(Click on YICS blanking tool for larger view)

[49er]

Wrong. My problem is, I'm TOO much of a cobbler. I refuse to accept anything less than professional and perhaps carry it a bit too far. Being a professional mechanic by trade, I expect precision and perfection from others and assume they expect it from me.
The YICS blanking tool I built for my '81 Seca is nothing short of professional. In fact, I've sold several of them to others and received high praise for them.
The remote fuel tank I built is probably better than the one sold by Motion Pro. In fact, I'd bet my paycheck on it.
You all are quite correct in assuming a home-brewed apparatus will suffice for the occasional home tuner working on his own machine. My point was, when people are paying you to work on their machines, they expect a little more than aquarium tubing and tranny fluid, and quality and precision is not that expensive at under 100 bucks. A couple of carb synchs for friends and aquaintances will easily pay for a good set of carb sticks, with a ColorTune thrown in, to boot. However, I don't want to hijack your thread, so I'll bow out quietly and leave you all to it.
(Click on YICS blanking tool for larger view)

I agree with your sentiments. However, many of our members are on tight budgets, so the chance to fathom out ways of fabing up cheap alternatives to recognised tuning tools is appealing.
I must admit, that in my early days of engine tuning, I would also try methods that were unconventional. There were a lot of heart aches and waisted hours and dollars (or pounds in those days) along the way, but I did learn what parameters that one needed to work within. This learning experience can't really be gained out of books, but is never forgotten through personal triumph or failure.

[seuadr]

Wrong. My problem is, I'm TOO much of a cobbler. I refuse to accept anything less than professional and perhaps carry it a bit too far. Being a professional mechanic by trade, I expect precision and perfection from others and assume they expect it from me.
The YICS blanking tool I built for my '81 Seca is nothing short of professional. In fact, I've sold several of them to others and received high praise for them.
The remote fuel tank I built is probably better than the one sold by Motion Pro. In fact, I'd bet my paycheck on it.
You all are quite correct in assuming a home-brewed apparatus will suffice for the occasional home tuner working on his own machine. My point was, when people are paying you to work on their machines, they expect a little more than aquarium tubing and tranny fluid, and quality and precision is not that expensive at under 100 bucks. A couple of carb synchs for friends and aquaintances will easily pay for a good set of carb sticks, with a ColorTune thrown in, to boot. However, I don't want to hijack your thread, so I'll bow out quietly and leave you all to it.
(Click on YICS blanking tool for larger view)

thats the difference between me home brewing a manometer for my personal use and you. of course if i were getting PAID to do it, i'd buy the best manometer i could afford.:-D

[Colorado CJ]

Just found this post on another forum. Guy has a 4 page .doc file on how to build a carb sync. for 4 carbs. Looks GREAT and easy to build. I'll be building mine tomorrow.

http://www.venturerider.org/forum/showthread.php?t=14076

Here's how it looks:

[tkent02]

Just found this post on another forum. Guy has a 4 page .doc file on how to build a carb sync. for 4 carbs. Looks GREAT and easy to build. I'll be building mine tomorrow.

http://www.venturerider.org/forum/showthread.php?t=14076

Here's how it looks:

Can't get into the article without joining, can you post it up for us?

[posplayr]

Now that is a manometer

Bigger is better right?:-D
Well it appears the guy(do gals do this type of thing?) that designed it knew something about engineering.

Based on the volume of ATF, he probably gets good "averaging" of the intake pulses and you would have to rev to 10K RPM to suck that amount of fluid from the tubes.

Is this a marketable product??? Probably not. It does probably work better than most manometers.

Pospalyr

[Colorado CJ]

Here's a pdf file i converted from the doc files so you don't have to join:

http://www.mediafire.com/?1gnfzyuwm2u

[Dogma]

....
Based on the volume of ATF, he probably gets good "averaging" of the intake pulses and you would have to rev to 10K RPM to suck that amount of fluid from the tubes.

...

Pospalyr

The volume would help with the pulsing, but not with keeping the fluid in the manometer. When calculating how high a fluid can be lifted with suction (or pressure, of course), the diameter of the tube falls out of the equations. I worked out similar problems at school. Height, density, and pressure difference are the only relevant variables.

[posplayr]

Dogma

Well technically you are correct that the steady state levels of the fluid in the tube are only based on the pressure differential and the amount of head produced by the column height differential (i.e. density of the fluid and height). However in the case of usability, if you blip the carbs, it will take longer to evacuate that larger volume over the ATV than if the tube was narrower and so you have longer to react (i.e. back off the throttle). With narrow tubes, it is virtually impossible (ask me how I know).

I worked out the equations recently and basically the ratio of volume in the standing tube to area of hose represents the electrical equivalent of capacitance (If I remember correctly; I'll post the results if i can find it) and given this works against some flow resistance in the line there is the equivalence of a RC filter which provides the dampening but also will delay the rise in the column according to the same linear filter theory.

Taking this to the extreme with a simple example, should make the effect more clear. If you basically have two large several cubic feet of air space above each column of ATF, yes the ATF level will approach the level required to balance the pressure above the fluid, but restrictions in the flow of either ATF fluid between the tubes and or air above the fluid in exhanging through a small tube will create the RC filter effect I have described and so it takes a while for pressures to equalize even though the ultimate levels are independent(your initial point) of the capacitance.

You will note that the fluid tubes and tee's below the manometer are much smaller than the standing tubes as well as the size of the vacuum hoses above the fluid. I suspect this has very good damping properties due to both forms of capacitance.

Posplayr

[tkent02]

Rocket science again.
You guys.
Take a simple and functional concept and turn it into Something that hurts my head.
Let's see some equations.

[Dogma]

Well technically you are correct that the steady state levels of the fluid in the tube are only based on the pressure differential and the amount of head produced by the column height differential (i.e. density of the fluid and height). However in the case of usability, if you blip the carbs, it will take longer to evacuate that larger volume over the ATV than if the tube was narrower and so you have longer to react (i.e. back off the throttle). With narrow tubes, it is virtually impossible (ask me how I know).

I worked out the equations recently and basically the ratio of volume in the standing tube to area of hose represents the electrical equivalent of capacitance (If I remember correctly; I'll post the results if i can find it) and given this works against some flow resistance in the line there is the equivalence of a RC filter which provides the dampening but also will delay the rise in the column according to the same linear filter theory.

Taking this to the extreme with a simple example, should make the effect more clear. If you basically have two large several cubic feet of air space above each column of ATF, yes the ATF level will approach the level required to balance the pressure above the fluid, but restrictions in the flow of either ATF fluid between the tubes and or air above the fluid in exhanging through a small tube will create the RC filter effect I have described and so it takes a while for pressures to equalize even though the ultimate levels are independent(your initial point) of the capacitance.

You will note that the fluid tubes and tee's below the manometer are much smaller than the standing tubes as well as the size of the vacuum hoses above the fluid. I suspect this has very good damping properties due to both forms of capacitance.

Posplayr

Are you a EE?

Makes sense to put a vacuum reservoir over the liquid. Not having balanced carbs yet, I didn't recognize the danger of getting the fluid moving with sudden throttle changes. This should tend to reduce bouncing too.

A similar stabilizing effect could be achieved by spooling some extra tubing on the ground to increase the total fluid inertance of the ATF, or using a larger reservoir. Maybe pull water from a filled gallon jug. I remember "Inertance" is the term for the fluid version of inertia, which is mathematically analogous to inductance, IIRC. So we're looking at something like an RCH filter if we ignore the, uh, elasticity of the vacuum above our liquid, right?

A few loops full of vacuum would make some vacuum reservoir too. I don't know if the extra tubing would be more or less cost effective than the fittings, etc. necessary for for adding flow restrictors, or those nice fat graduated cylinders, or connecting the lines together at the bottom.

Thanks for the heads-up on getting the liquid moving. I'll have to remember when the time comes (probably later this summer).

..."full of vacuum". What a concept.

[posplayr]

Full of Vacuum

"I resemble that remark" Archie Bunker, All in the Family

I remember "Inertance" is the term for the fluid version of inertia, which is mathematically analogous to inductance, IIRC.

http://www.diracdelta.co.uk/science/...ce/source.html

<B>

<H1>Inertance

</B>

Inertance is the ratio of an acceleration-like quantity to a force-like quantity when the arguments of the real (or imaginary) parts of quantities increase linearly with time.

</H1>

I had never heard of that before. It looks more like an equivalent to mass (i.e. F=ma ==> 1/m=a/F equiv. inertance).

m is basically a force scaler to determine acceleration, so there is no other dynamic than implied by the pure integrations of acceleration,a, to position x. (i.e. a=dv/dt, v=dx/dt ==> a = dx2/d2t)

Inductance ,L, has a single integration V=L (dI/dt) and capacitance ,C, a similar I = C (dV/dt). I guess mathematically we could have used either and equivalent of C or L for the accumulator analogy. C seemed more natural.

I have formal training as EE but have had one senior level fluids course (30 years ago), but have had to stay somewhat abreast of fluid and aerodynamics principles for doing aerospace related controls work. This of course is in addition to my detailed study of the subject to improve my own windsurfing equipment (20+ years ago)

There are any number of ways to add more damping, the real issue is practicality. The little twist valves I assume work well is they can close off the flow enough relative to the volume of air in the vacuum lines.

When I first ran into this problem (again about 20 years ago) one of the engineers I worked with at the time told me to add some accumulators in line with some vacuum guages that were bouncing too much. I took some pieces of 2" diameter PVC pipe (1 ft long), and duck taped the vacuum line into either end. I put this in line with the gages. This added significant damping from the what had been nothing but bouncing needles before.

Posplayr

[rustybronco]

suburban ghetto....

http://i32.photobucket.com/albums/d44/rustybronco/vacuumgauge005.jpg

[80GS750]

i think im gonna do something like that for mine....

nothing fancy.. just need to balance them all correctly

[posplayr]

Rusty

So how does it work? It is not clear what you did to reduce the needle bounce.
Posplayr