Syncing dual IDF clones per carb not per barrel

[Krochus]

Here’s a brain buster for ya.

What if anything is going to be different syncing carbs based on a reading taken on a inlet for a cb sand system carb hat versus on a per barrel basis on a velocity stack?

And GO!

[Dale M.]

For best sync use manometer and do it from plugged vacuum port at carb base (not air bypass screw).... Eliminate all the possible air leaks of snail not seating properly on hardware above carb body...

Dale
_________________
“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
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All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[Krochus]

[Dale M.]

About a million years ago, Weber made a 4 vacuum gauge manometer tool/kit that had all the carb fitting and such so you could do up to 4 barrels at one time....

On the bizarre place of youtube there is about a 100 videos using about 20 different ways/tools to make/attach manometer...

https://www.ebay.com/itm/WEBER-IDF-DCNF-VACUUM-TAK...mp;vxp=mtr

Alfa 1750 says it fits blocked (M4x.7)port on carb base..

I been sitting here wondering for last few days about the vacuum ports on carb for vacuum advance for distributor and wondering if there would be sufficient vacuum at that port to operate simple "bottle" manometer for side to side sync...

Dale
_________________
“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
============================================================
All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[modok]

I have one, but I don't often use it.

Syncing from air box? no difference. or, I don't understand.

[vwracerdave]

Each barrel must be sync'd seperatly. putting the snail gauge on the hat will just show an average of the two individual barrels and they will still be unequal.
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK

[Krochus]

[Dale M.]

Here goes getting a little more complicated, but how about a anti-pulse chamber on vac line to manometer... Recently was working with vacuum pump and "new gauge" and "new" location for gauge (at pump) it was fluctuating wildly.... Added about 6 feet of hose between pump and gauge and it smoothed it out considerably.... Maybe smaller diameter tubing on even inline orifice to modulate pulses to smooth them out...

I'm sitting here with a MAP unit off my Jeep and looking at it and wondering if I can put 5 volts and ground to it and read off sensor line with digital meter to see if I can get a variable reading off sensor if I vary the condition on input side... Seems to me if it worked one would have a electronic snail (manometer) connected to vacuum port on carb base...Sort of stand alone derived from what digital ignition/EFI uses...

Sort of like the idea to be able to sync carb from side to side with out having to remove air cleaners or plumbing from blower to spend just a few minutes turning a few screws a tiny bit..

Dale
_________________
“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
============================================================
All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[Krochus]

I’m totally going to stop by harbor freight on the way home and get a couple spare pairs of forceps to see if the KPA display on my Megajolt will be stable enough to make comparisons between one cylinder or bank vs the other.

Basically clamp off one bank, swap to the other. And compare the results.

The problem I see with this is your never gonna be able to compare anything but idle unless I can find a means to fix the throttle.

I need to set up one or two of my inputs to read an external map sensor or two like you are thinking....... then I could dataog carb sync

[slalombuggy]

Dale. That is how we used to test MAP sensors (not MAF) apply vokrage and grounf. Use a vacuum pum and beasure output voltage.

brad

[Dale M.]

[modok]

Ok now i think I understand the question. It's a silly question.
Adjust the screws so it idles smooth. If you are not sure, short out a cylinder and observe the rpm drop. Pull the boots up at the cap and use one of those poity screwdriver with a wire to short out each cylinder and not get zapped, is how most do it.
Get both sides equal.
Can be done all by ear once you get the hang of it.
Once it's done it's done, for a few years, or should be.

Before the carbs go ON, adjust both sides so the throttes are the same elative to the transfer ports, and just KEEP them equal. And, if they don't run equal, you will have a clue what is OFF.
This "backing out the screw and counting the turns" is IMO, complete baloney, and should never be done.

Getting them synced at part throttle is more important than idle, so I think you are worrying about the wrong thing. But, if you did have map sensors for both sides it would help you synch the linkage!!

[Krochus]

Lol before the carbs go ON?

This setup has been running and never resynced since the engine was built two years ago. It’s a little late for that. Over the intervening time since the build I’m pretty sure my linkage adjustment isn’t what it once was

If it wasn’t for the damn thing running so well and being so drivable I would go to a center carb or fuel injection. I’ve really grown to hate working around the carbs, linkage and associated plumbing not to mention the draggy throttle that has as much feeling as stepping on a dog turb. Definitely not taking the carbs off nor are the hats getting removed.

I can probably sync the mixture using thermal imaging on the exhaust as well as anything. (I have access to lots of cool toys)

I’m not sure I am prepared to pull a wire on a Ford EDIS coil. Not only is there a lot of juice there but it’s firing down each plug wire twice as often. I think that’s going to be a hard NOPE for me. You can try it and I will watch possibly recording video in hopes of YouTube glory.

[modok]

HA! your right. no way to do a power balance test. I guess you edis fanboys aren't so smart after all.

Good idea with the thermal imaging, Yes you can measure the balance many ways. power balance, flow, vac, temp, or just get it right before you put the carbs on, or by ear. You can do it! it's not that hard. And if it's off a little......so what? it won't hurt anything to idle a little funky.
If your sync is off at part throttle it might hurt something, so that should be a higher priority.

[Krochus]

Syncing the linkage for various throttle openings is the primary goal.

I’m honestly not concerned about the idle mixture at all. Not even a little

Lol you certainly CAN power balance with an edis. It’s just that your underwear might not survive and you might have a coming to Jesus moment and look like beaker The muppet

[modok]

I never thought about it real hard before but actually it's no different. You CAN do it, short out each plug, just the same, as it is done on any car.
Unplugging the wire will not work tho, but that's not the smart way to do it. the smart way is you have a screwdriver with a ground wire and short it out.
i am sure snap on and ect make a fancy one.....with extra good insulation for your comfort.

[oprn]

It's amazing what can be done with simple tools. I set mine up with a heat gun on the exhaust stubs and a set of bottles on the carb vacuum ports on the bottom of the carb below the throttle plates.

I tried using vacuum gauges both analog and digital. It does not work! As said above the pulsation is far too great to get any usable readings. Orifices may work but it would take a lot of trial and error to get them the right size. The Weber 4 gauge panel no doubt has them in there. And no, smaller tubing makes the problem worse not better! You need volume to dampen the pulsations out. That is why the bottle method works so well.

A snail gauge for me was completely useless as I do not have enough room to use one with the engine installed in the car.

As far as syncing the individual barrels on the same side at idle, like Modoc said I just tweak them by ear. I have intended to go back and try it with the bottles but it idles so nice now I haven't bothered yet.