How To: Make a 2 bottle synch tool

I would think it would need to be level. The fluid is subjected to the pressure difference and gravity in a manometer, thus if the pressure is not equal then the difference in pressure is enough to "lift" a certain mass of fluid. Steady just means a good reading. http://en.wikipedia.org/wiki/Manometer#Liquid_column

When I set this up, it took the fluid a long time to go from one bottle to the other, so the result was that I kept waaaay over correcting. Am I right in assuming that the ATF does not have an immediate response?

 

here's something i've been pondering. i like the 2 bottle synch because if built correctly, it guarantees no cylinder will suck up all the ATF. but i also like the board/hoses synch because it allows you to see all 4 cylinders at once.

question: do you think a 4 bottle synch could be made by connecting 2 2-bottle synchs together? keeping in mind to only fill them just under 1/4 full instead of 1/2.

 

I think a four bottle synch tool would work. I was just thinking about trying to make a 4 carb sync tool with a fifth common source bottle, but I think just plugging two together would be alot easier.

 

I too made one of these bad boys but my connecting tubes were longer and i placed them on a board like the real sync setup. i thought it worked sweet .pics will follow .thanks to all those before me that came up with the thoughts and designs


cheers john

 

Level in bottle does not have to be same. The vacuum each cylinder is what cause the fluid to move from one bottle to the other. More vacuum creates less pressure in the bottle. This will cause fluid to move from one bottle to the other. If the vacuum is equal the fluid will not move between bottles regardless of its level. The only thing to remember is the fluid has to cover the hose that is connecting two bottles. If not it will not work. One thing to watch out for is a very small leak in the stopper will mess up readings. I have used this many times and like it but if your stoppers dont seal good it can be frustrating.

 

Well this is what my 4 bottle set up looks like. and it works well bike goes like never before.sorry its in my gallery

 

The level in the bottle does have to be the same to have equal vac pressure. If the fluid is connected, in order for the fluid to have a different height, there has to be a force "holding" it up. That force is a difference in pressure. Try this experiment . Take your sync tool, primed (with fluid in the connecting tube), but with the tubes exposed to the atmosphere. Make sure the fluid in the level bottle is equal. Now raise one of the bottles by putting a 2x4 underneath it. You won't see the fluid flow immediately (because of the viscosity of the fluid, the weight of the fluid, and the size of the connecting tubes), but leave it for a while and the fluid will end up being at the same level, because they are exposed to the same pressure.

 

Hey johnboy_28, I noticed your 4 bottle sync tool <here> didn't connect bottles 1-2 to 3-4. This means that 1-2 aren't going to be synced relative to 3-4 (this is the middle sync screw, the final step). I wonder if all you would have to do to that set-up is cut the two connecting tubes, then attach them to a cross tube. That way, all four bottle could share the fluid.

If you don't try it, I will soon.

 

lets say you got a 4 bottle setup, the motor is hot with a fan on it, the idles not to good because the sync is still off
now 1 is going down, 2 is going up, 3 is going up, 4 is going down, what screw do you turn first ? quick, the #2 is getting full and 4 is almost empty
and you still have to get on the screw of choice and turn it the right way
and if you get lucky and get on the right screw and turn it the right way the idle shoots up to 2500 and you've got to turn it down while the other bottles empty and maybe suck liquid in the intake
why not keep life simple and use 2 bottles

 

Hi again

just one query but why do 1/2 & 3/4 bottles have to be connected if they are all pulling the same vacum they should all come up the tube at the same time true?which would show that they are all equal .if you are getting full flow from bottle to bottle then this would mean there is an air leak in one of the bottles right ? but you are not trying to measure flow but vacum which is what i thought my set up achieved for me . but first off i bench synced my cards first which would mean that they are fairly acurate any wayand wouldnt be going up and down that much . will try to post video on you tube or something of the like and you can see it in action.

 

1&2 can be sync'ed at a different overall level and still look exactly the same, and level with 3&4. But then you would just hook 3 to 2 and plug off 1 and 4 and set the final sync.

Now THIS JUST IN !!
A new sync tool so simple, even Schooter could use it !

*Get a BB from a BB gun
*use some of that clear tube to construct a horizontal, shallow bend.
*make 2 RickCoMatic union restrictor baffle things

The idea is the BB settles to the middle-bottom of the one foot shallow bend, (looks like a wide smile) and a vacuum imbalance pulls the BB left or right. The BB stops at the union-restrictor. This device would allow a "rough" running sync without a $25 gauge, or sucking water into an engine, or trying to quickly figure out a bottle sync.

After that, a 2 bottle sync will nail it. Wlhile I enthusiastically promote a 4 tube Manometer (because they are so cool to use) I think the first timers to syncing should just use the very large loop method with the restrictor in the water itself. So, the BB device could go in the bottom first, then water.

I should draw this. . .

(oxygen mask tubing and connectors work well for the top of the system)

 

Polock is right about the practical issues for what i suggested. The reason not connecting the bottles doesn't balance 1-2 to 3-4 is because you aren't measuring "vacuum" persay, but instead measuring a difference in pressure between two intakes. The 1-2 bottles could pull the same vacuum and be level, and 3-4 could do the same, but that doesn't mean that 1-3 or 2-4 (or 1-4 or 2-3) would pull the same vacuum. Remeber, this tool measures a difference in pressure, not the actual pressure.

 

Thanks guys
that shot my theory out the window

 

Hey no worries, you still only have to connect it twice each time you balance

 

don't give up yet guy, if the three hoses that connect the bottles to each other had valves in them, by closing the right valve it becomes a 2 bottle setup then when it's all setup and done, open them all and it's a 4 bottle again and very impressive
now if you put a different color water in each bottle.................

 

I think the "Bottle-type" Sync Tools have a Flaw you need to overcome.

The Mercury reservoir on my "CarbTune Carb Sticks" is a COMMON Volume of Heavy Metal feeding all four tubes.
The Vacuum draws-up Mercury from a Single source.

I think these Bottle systems need that Common element too.

I bought the set of Carb Sticks back when I was doing four or five bikes a season.
If I was only concerned with getting my own Bike accurately synced; I'd Hook-up 4 Vacuum Lines to an Aquarium Air Valve Set-up with a Restrictor element to soften the fluctuations and use a single Vacuum Gauge and shoot for accuracy.

 

if two containers of H2O are connected with a hose they are a common source

 

What are the units on the carb sticks? Because the specific gravity of ATF is 0.875 (this is a quick google number) and the specific gravity of mercury is 13.6. This means that the two bottle tool is 15 times more sensitive than the mercury sticks, but I'm sure the area of the reservoir is greater than the tubes, making the sticks more sensitive.

Lets do some math:
Given that the bottles are about 6 inches high (15cm), the pressure difference that can be measured is 15cm*density_of_ATF*g which is about 1.28 kPa or 9.6 mmHg or 0.38 inHg. Another quick google search showed that combustion engines pull between 18-22 inHg (61-75 kPa) vacuum. This means that the range being measured could be assumed to be 4 inHg or 14 kPa . So the main problem with this tool in my opinion, is that it cannot accommodate the range that the manifold vacuum can be. To accommodate a range of 14 kPa, we need to make the two bottle sync tool about 1.6 m tall. I guess this is why the viscosity is a good thing, slowing the readings down. If it just jumped to a stead reading, you'd lose fluid too fast. I'm not quite ready to tune, but when I am, I might try different diameter tubes for connecting the fluid to get a better response. I think the tube I have now is too small.

 

"If two containers of water are connected by a hose at the top ... they are two SEPARATE containers of water connected by a hose ...

UNLESS ... the two containers are connected AT THEIR BOTTOM, such that GRAVITY will keep the LEVEL of the fluid in the two at EQUAL HEIGHT to display LEVEL

Without the BOTTOMS connected for the Level to be affected by a pressure change ...

The only thing that can happen is for the hoses to collapse.

 

manbot, 1/4 id hose , 2 snapple bottles and no leaks, your good to go

Rick, are you really ready to tell anyone who might read this that a two bottle sync setup doesn't work ?