Topic: Mercury sync. got moisture in it.

[jeremiah]

I just bought one of the 4 tube mercury sync things and after using it a few times some moisture has developed in the tubes.  Is this normal?  What happened?  It gets in between the mercury.  So do I use the top of the mercury to measure still?  Would the device work using only water & no mercury?  Anyway to safely remove the moisture? 

[Gordon]

Same thing happened to my merc sticks, and I never figured out a way to get rid of it that worked for more than a couple of minutes.  My only piece of advice is to cut your losses and buy a Morgan Carbtune.

[jeremiah]

I would consider buying a better one, but I seriously just bought it and used it 2 times...  What about a little heat to dry it out?  is that dangerous?  Plugging the tubes with some kind of moisture absorbent material? 

[Bob Wessner]

Heating mercury is extremely dangerous unless done properly, which generally mean under some sort of hood with ventilation. I wouldn't recommend it. Unfortunately, I have no other ideas on removing the water. Perhaps someone will jump in here with a safe idea.

[super pasty white guy]

Never had a carb sync, so I'm just suggesting an idea-  How about silica gel and an airtight jar?  Silica gel is available from craft stores and is used for drying flowers.  Definately don't use heat as it will cause mercury vapor to be released-  mercury is toxic (that's where the phrase mad as a hatter came from).

Dave

[Bodain]

It doesn't matter. What a sync guage reads is not all that important. We only really interested in the differences in readings. The goal is to get them as close as possible and eliminate the difference.

The other significent thing to keep in mind. You could infact take the Mercury out and put in colored water, or oil. However since Mercury is far heavier than oil or water you would need to extend you gauge another 24 inches. If you use a lighter fluid. The standard vacuum would be pushing the lighter fluid much higher in the tubes. The existing length would probably overflow immediately using water.

[Bodi]

24 inches longer? maybe a bit more...
Absolute vacuum is about 29 inches of mercury, but about 34 feet of water. The water column, regardless of vacuum (the intake manifold is not going to get to absolute vacuum) will be 14 times higher than the mercury column. So if you are pulling 6 inches Hg that would be a 7 foot high water column.
Just pour out the mercury into a cup, sop up any water off the top with a paper towel, and refill the carb stix reservoir. Don't get mercury on anything aluminum (major weakening results) and don't use any utensils involved in the transfer for food afterward. Do the pouring outside. Take any gold jewelery off and wash your hands thoroughly before putting it back on, gold and mercury love each other.

[black-dahlia]

I got this reply during the summer from the people at motion pro (the ones who make my mercury sticks)...Something just jumped into my head to post it now...Hope it might still help someone out there...

Q: Gaps have formed in the mercury columns. What can I do to correct and prevent this?

A: It is likely that condensate (fuel and/or water) has formed and has partially mixed with the mercury. Using a syringe without a needle (or other small volume manual air pump) force air through each hose until air bubbles are gently forced into the reservoir. This forces the condensate into the reservoir where it will float on the surface of the mercury. The condensate does not weigh much compared to mercury so if you are unable to remove it the error caused is negligible as long as approximately equal amounts are in each channel (tube).

The fuel segment of condensate can be kept to a minimum by either warming the engine up to operating temp prior to connecting the manometer (carb synchronizer), or by pinching off the vacuum lines with plastic hemostats (available from tool trucks) for that purpose until operating temperature is reached. Water condensate is unavoidable due to the “atmospheric” conditions present in the intake tract at idle.

Another reason for gaps in the mercury column is because the reservoir is low. The tool should not be used until the reservoir is refilled to the correct level. Continued use will result in the remainder of the mercury being ingested by the engine. Once the reservoir has been depleted enough to allow air to be drawn into any tube from the bottom, the engine will have sufficient vacuum to draw the remainder of the mercury into the intake tract(s).

[OldSchool_IsCool]

To get the water out, try leaving the tubes in the sun with the ends open to vent. 

Consider also building your own carb sync tool like this one.  I've spent maybe $5 on the parts so far.  I have yet to use it as I'm looking for the correct tube barbs to screw into the vacuum ports.  It's filled with water dyed with food color and relies on the carbs to push/pull against each other to establish each carb's relative vacuum.  You won't get absolute pressure or even trend data from this, but do you really need it?

[eldar]

Now that setup is pretty decent. Maybe more info on how it works is in order then maybe a migration to the faqs.

[Jonesy]

The nice thing about the Carbtune is that you can turn it upside down and blip the throttle to suck any of that stuff out. You wouldn't dream of doing it with a Merc stick...

[OldSchool_IsCool]

More explaination of how the homemade carb sync tool works can be found at this thread:

http://www.sohc4.us/forums/index.php?topic=13855.0

[Serge]

Hey, I made up a device just as on pictures OldSchool_IsCool  posted. I made it couple feet long and filled with ATF for 5 inches or so. I bought 5mm adapters for a buck each from www.casporttouring.com. I connected it all up and crancked the engine with starter with kill switch off. Cylinder #3 immidiately sucked  some ATF in.  I bought a  single vacuum gauge at autozone ($25) and adjusted it to be about the same as other. Still, I could not use the setup since the ATF was getting into cylinders on crancking the engine. Probably if I would make the tubes lionger and start it up it would work better at high RPM, but this construction probably would work best synchronizing 1 and 4 and 2 and 3 ... 
Anyway, since I got a gauge now I guess I will stick with it..

[OldSchool_IsCool]

Serge,

Thanks for reporting your experiences with the setup.  I'm hoping the ingested ATF didn't make for a bad day!

Hmmmm.  I'm guessing that the fact that the cylinders are not all sucking at the same exact time may be the reason a cylinder will ingest liquid.  I wonder if the flow between the tubes were restricted by a pin hole such that free flow of fluid was not possible that the setup might work better.  Maybe add valves and slowly introduce a tube to the mix?  Maybe an in-line air chamber that is at least 1 quarter the volume of your engine (about 150cc for a 550, 200cc for a 750).  I can see that the intended benefit of the setup (i.e cheap!) is quickly evaporating!

At any rate, I would like to get ahold of the 5mm port barbs.  Do you have the product number/ordering info for them?  I searched the site and couldn't find them.

[Serge]

Serge,

Thanks for reporting your experiences with the setup.  I'm hoping the ingested ATF didn't make for a bad day!

Hmmmm.  I'm guessing that the fact that the cylinders are not all sucking at the same exact time may be the reason a cylinder will ingest liquid.  I wonder if the flow between the tubes were restricted by a pin hole such that free flow of fluid was not possible that the setup might work better.  Maybe add valves and slowly introduce a tube to the mix?  Maybe an in-line air chamber that is at least 1 quarter the volume of your engine (about 150cc for a 550, 200cc for a 750).  I can see that the intended benefit of the setup (i.e cheap!) is quickly evaporating!

At any rate, I would like to get ahold of the 5mm port barbs.  Do you have the product number/ordering info for them?  I searched the site and couldn't find them.

ATF is good for the engine I suspect that the red "magic oil" people recommended to add to the gas to prolong engine life at severe conditions is in fact relabled ATF. I used to add it to diesel fuel of my old Mercedes before it seized from overheating 

the adapters are going for twinmax on that forcasporttouring site
http://www.casporttouring.com/store/merchant.mvc?Screen=PROD&Product_Code=24003&Category_Code=twinmax

In the Clymer manual there is a description of DYI synchronizer with water, but those are in fact four separate home-made manometers and they also write that one might need to make stabilizers out of tin cans. that one is way too much work, IMHO.  I do not see why one could not set it withing specs with single vacuum gauge? Vacuum readings should not change much with rpm, right? And adjusting throttle in one carb should not affect others too much, I guess...

[Ibsen]

Same thing happened to my merc sticks, and I never figured out a way to get rid of it that worked for more than a couple of minutes.  My only piece of advice is to cut your losses and buy a Morgan Carbtune.

I agree. When you have tried the Morgan tool you will never regret it.

[OldSchool_IsCool]

Serge,

Thanks for the link to the TwinMax 5mm vacuum port barbs.  I have 6 of them on the way! 

I've got a few ideas on how to make the setup work and still remain inexpensive.  Thanks also for the tip on the ATF fluid.  Sounds like ATF ingestion would be better then water ingestion, so I'll switch to that.  I'll also be able to fill the setup once with no fear of freezing while stored in the garage.  I'm also considering dropping a Styrofoam "bead" on top of the liquid in each tube.  The bead would need to be smaller then the tube, but larger then the inside diameter of the barb.  My thought is that, if a carb does try to suck in fluid, that the bead would rise to the barb and for the most part seal it off.  The bead would also be easier to see and may dampen the effects of the out-of-phase vacuum applies to each tube.  I'm thinking that there will be an RPM range where the levels will be pretty much stable.

[Namba1032]

Its not hard to get the moisture/ fuel out of the mercury... I recently did this and considering the density of water or fuel is much less than mercury (hense the fact that it floats on top of it) I just used a syringe to pump out the mercury back into the bottle it came in. Just suck out the mercury from the bottom of the reseviour until you suck up all the mercury leaving the moisture/ fuel bubbles behind. Then I took the tubes, blew them out with an air compressor, and hung it up and let it evaporate. Now when I need it again, I'll just pour it back in and do it all again.

The only thing you are trying to get at is all 4 carbs pulling the same level, it may jump around a bit but just keep tuning it at differnt rpm ranges, basically the higher the rpms are the more stable readings you will get, just make sure not to suck the mercury up to high and into the engine. I wouldnt bother making a new setup, you already have one that works.

Brian

[Serge]

The bead would need to be smaller then the tube, but larger then the inside diameter of the barb.  My thought is that, if a carb does try to suck in fluid, that the bead would rise to the barb and for the most part seal it off.  The bead would also be easier to see and may dampen the effects of the out-of-phase vacuum applies to each tube.  I'm thinking that there will be an RPM range where the levels will be pretty much stable.

I would suggest to make four separate manometers, like in clymer manual, but simpler, e.g. like in the file attached. One need to make the tubes of equal length and to fill them to the same level. It still seems less work.. The problem with ATF, and to the less degree with water, is that it wets the surface of the tube, that is why mercury is used instead in thermometers and manometers...