Excellent carb balancing tool?

[svejkovat]

Would this not?
https://www.zoro.com/dwyer-instruments-pressure-gauge-1-in-to-0-to-1-in-h2o-2302/i/G0563857/
 
Includes: Instructions, Two 1/8" NPT Plugs, Two 1/8" NPT to 3/16" I.D. Rubber Tubing Adapters and Three Mounting Adapters with Screws

Dead simple.   Left port to left carb, right to right.

More expensive than a DIY tube manometer.   Less messy. Way cooler.

[mrclubike]

It may  be   to sensitive

1 inch of water equals .073 mercury

[mrclubike]

This would work

[Barry]

Magnehelic gauges are available with other pressure ranges. They are used extensively for clean room pressure monitoring.

I think the attraction of either of these differential gauges is the ability to strap them to the tank for balancing the carbs under actual riding conditions.  It would be interesting to discover if a statically balanced carbs maintained that balance under load.

[svejkovat]

A 1.5 inch diameter version of this, with a couple of micro plumbing mods to make it register vac/vac instead of vac/press
would be very fun to mount on the dash in place of the BMW roundel and plumbed to the carbs.  Constant monitoring of vacuum.   

I wonder if sealing the case against atmosphere and putting a port to that internal volume would work to balance the vacuum seen by the bourdon tube to zero?  One carb to the inside of the bourdon tube as normal, other carb to the case volume acting against the tube externally.

Just some fun musings.  Not really serious.

[georgesgiralt]

I'm fortunate enough to own a "Grok analyser" (RIP, Grok) and I have to admit I used it scotched to the tank while running.
The vacuum is not a steady thing and balance vary through the range of RPM. I think having the carbs balanced at idle and on various regime, under load is a dream... But it was fun to play with this device ! And i admire Grok to have designed such a clever device.

[Barry]

I wonder if sealing the case against atmosphere and putting a port to that internal volume would work to balance the vacuum seen by the bourdon tube to zero?

Interesting ideas.

Yes it would work in principal although sealing the case wouldn't be easy. 

Getting on for 50 years ago I served an apprenticeship in instrumentation and spent quite some time calibrating gauges.  Differential pressure gauges at least in low ranges were diaphragm based as indeed is the modern Magnahelic gauge. There were some dual tube Bourdon gauges but to get a bourdon tube to work at low pressure means the tube becomes a lighter construction.

Based on using a yard stick manometer I would want a sensitivity of 1" of water or better which is 0.036 PSI and that's going to be difficult to read on a bourdon tube gauge. Full scale to allow for gross in balance would need to be no more than 28 in water or 1.0 psi.

[svejkovat]

 





... with a  little ported 12v vacuum sensor mounted conveniently under the tank.   there are many many versions of "zero center scale" meters and gauges out there.

Barry, I wonder if you might be able to identify a couple of components I might order for tinkering with. 

What version of the following SMD vacuum sensors might be appropriate for a pretty straightforward application to the
little meter shown above?

https://www.arrow.com/en/products/mpx2010dp/nxp-semiconductors?utm_source=google&utm_campaign=g-shp-us-sensors&utm_medium=cpc&utm_term=PRODUCT+GROUP&gclid=EAIaIQobChMIuL2G3dDR3AIVBgppCh1sLQ_bEAYYASABEgJzkPD_BwE&gclsrc=aw.ds&dclid=CM_JiO3Q0dwCFQJZwQodCtAEtA

There is a PDF datasheet link on the page that describes the various packages of these sensors


This is a data sheet on the LED meter...
https://www.lascarelectronics.com/lascar-panel-instrument-ema-1710/

[Tony Smith]

Surely Guys, you are over thinking this.

Stuff like
https://www.youtube.com/watch?v=Y_WDF6glD5k

or

https://www.youtube.com/watch?v=6NSpAuUvln8


Costs pennies to make, are safe and deathly accurate. I own both gauges (getting old) and a Motion Pro Carb stix but I use a setup similar to the first one because it is quicker and easier to use. unlike an earlier system I once used it is impossible for the engine to suck in the indicator fluid (you would be amazed at how much smoke an R65 can blow whilst digesting about 1/2 cup of kerosene mixed with ATF.

Anyway, toys, particularly electronic toys, are all very good, but lots of times the simple old ways are better and cost way less.

[DadsR65]

Surely Guys, you are over thinking this.

Stuff like
https://www.youtube.com/watch?v=Y_WDF6glD5k

or

https://www.youtube.com/watch?v=6NSpAuUvln8


Costs pennies to make, are safe and deathly accurate. I own both gauges (getting old) and a Motion Pro Carb stix but I use a setup similar to the first one because it is quicker and easier to use. unlike an earlier system I once used it is impossible for the engine to suck in the indicator fluid (you would be amazed at how much smoke an R65 can blow whilst digesting about 1/2 cup of kerosene mixed with ATF.

Anyway, toys, particularly electronic toys, are all very good, but lots of times the simple old ways are better and cost way less.

Agreed.  I use a long vinyl hose stapled in a big U shape on and old piece of baseboard trim filled with ATF.  Works great.  Cost $0 (built from junk in the basement).

Here's a pic of one similar to mine (not mine, but found the pic on the net):

https://www.superhawkforum.com/forums/attachments/technical-discussion-28/12736d1320209312-my-home-made-carb-synchronizer-manometer-manometer.jpg

[Barry]

Barry, I wonder if you might be able to identify a couple of components I might order for tinkering with.

What version of the following SMD vacuum sensors might be appropriate for a pretty straightforward application to the
little meter shown above?

All of the pressure sensors seem to have the same range and output  of 0 -10 kPa  and 1 - 26mV  That's not too bad range at approx 40" water gauge if a little high by my previous criteria. The problem is that the output is only 1-26 mV  while the meter is 1 volt FSD so it's not going to work. Well it would sort of work but a change of 1" WG would only deflect the meter by 0.07% of it's full range. If the meter was matched to sensor then it could work much better.

[svejkovat]

Surely Guys, you are over thinking this.

Without a doubt! 

I have the 5 dollar plastic tube and yardstick manometer mounted to my garage wall.  Ok, 10 dollars... I added a brass needle valve to the bottom for damping (I very highly recommend this).

Filled with red ATF.  Yes, it's really not to be improved upon for cheap and elegant toolage.

But this is just nerdy stuff.   For many years I belonged to DiyAudio.com.  The entire site would make a nice study in people overthinking things just for the fun of doing so.

If it could be done in any sort of plug-n-play fashion, I'd love to dash mount a little round zero center scaled mechanical/analog meter connected to the carbs by tubes.  If not, perhaps an mA or volt meter with a couple of sensors.

But, conceded, it's looking less and less plugnplay, and perhaps not worth the effort presented after all.   

Still an interesting "what if" to tinker in my head, beer in hand, on this sunny day in west Michigan.


Postscript.... I did watch a few youtubes on the two-bottle manometer.  YMMV of course, but  it appears to me from watching these videos that the needle valve dampened simple loop manometer can be adjusted to be much more responsive and almost equally safeguarded from sucking fluid into the carbs.  The levels in the bottle manometer appear to respond very slowly to adjustments.  The loop manometer with damping valve has a much quicker response that can be 'tuned' to taste with the damper.

[Tony Smith]

Here's a pic of one similar to mine (not mine, but found the pic on the net):

https://www.superhawkforum.com/forums/attachments/technical-discussion-28/12736d1320209312-my-home-made-carb-synchronizer-manometer-manometer.jpg

That is exactly what I used originally, it is also the type of device that due to inattention on my part the poor R65 ended up swallowing the indicator fluid, fortunately to no harm to itself.

Which is why I now prefer the "two bottle" method with sufficient air gap so that even if all the fluid transfers from one bottle to the other it will never rise high enough to be ingested by the engine.

[svejkovat]

Here's a pic of one similar to mine (not mine, but found the pic on the net):

https://www.superhawkforum.com/forums/attachments/technical-discussion-28/12736d1320209312-my-home-made-carb-synchronizer-manometer-manometer.jpg

That is exactly what I used originally, it is also the type of device that due to inattention on my part the poor R65 ended up swallowing the indicator fluid, fortunately to no harm to itself.

Which is why I now prefer the "two bottle" method with sufficient air gap so that even if all the fluid transfers from one bottle to the other it will never rise high enough to be ingested by the engine.

With the tube manometer damped sufficiently with a needle valve, with full vacuum on one carb and none on the other you'd literally have to be trying to suck fluid into the carb as slow as it rises up the tube.  There is more than ample time to shut down the engine or full stop the valve.

[DadsR65]

Here's a pic of one similar to mine (not mine, but found the pic on the net):

https://www.superhawkforum.com/forums/attachments/technical-discussion-28/12736d1320209312-my-home-made-carb-synchronizer-manometer-manometer.jpg

That is exactly what I used originally, it is also the type of device that due to inattention on my part the poor R65 ended up swallowing the indicator fluid, fortunately to no harm to itself.

Which is why I now prefer the "two bottle" method with sufficient air gap so that even if all the fluid transfers from one bottle to the other it will never rise high enough to be ingested by the engine.

Fair point.  If the carbs are way out of balance, it does take some quick reflexes.  I have really long tubes (maybe 10' from manometer to carb?) because I had the tube laying around.  Gives a little extra time.