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Carb Sync Tool on Steroids


Jeremy MacGregor

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http://i933.photobucket.com/albums/ad173/rotaxguy142/carbsync2.jpg

 

http://i933.photobucket.com/albums/ad173/rotaxguy142/Carbsync1.jpg

 

 

 

 

First time trying to upload an image on here so I hope it works.

 

Im posting some pictures of my "New" carb balancer which combines my manifold pressure gauges and a Syncromate in one handy tool. This way I get to see absolute manifold pressure on the gauges for a course adjustment and I can fine tune with the syncromate to get the carbs within a half inch or so of Hg. Wish I can take credit for the idea but Mr. Lee had recommended building one a while back.

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Hi Jeremy,

 

You went downtown on your setup. It will work great. The gauges to tell you which carb and how much and the Syncromate to fine tune the last .5 or less vacuum. I was thinking a tad smaller. unsure.gif Just use a 2" dial vacuum gauge (like the ones below) and splice it right in line with the Carbmate or Syncromate tubes about 2"-3" from the out let side of the instrument. You don't need the board or anything else, just one small gauge spliced in each Carbmate or Syncromate line. Let me know when you take it for a test run. I think you will like it. It definitely is carb sync on steroids and the best of two instruments and the best way to get it down to a nat's rump. unsure.gif

A nat's rump just doesn't sound the same. wink.gif

post-3-0-63565700-1308836627_thumb.jpg

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What a cool idea, I have to make one of these. Speaking of Roger he was right on regarding balancing @ 3600 rpm ( not that I doubted him). I recently rebalanced and mine were on @ 2000 but way out @ above 3000. It took hours ( my first time) but rebalanced @ 3600 . Smooth as a babys behind @ 3600-3800 and just a smidge off @ 2000. What did surprise me was when I re-connected the equalization tube the engine was noticably smoother at 2250. Have no idea why but you could feel it while taxing.

 

al meyer

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Hi Guys,

 

When you balance your carbs they will usually always be a tad smoother when you reconnect the balance/crossover tube. I would never let anyone balance my carbs at less than 3500 rpm. I have seen a couple of shops balance at 2500 and the carbs will always be off at 3500-4000 rpm. You fly closer to the 3500-4000 rpm. 2500 is for idle. Tell a shop if your capable of balancing at 2500 then you can do it at 3500-4000. Once you get used to doing carb balancing then any rpm is just as easy to do. I will state for the record that some planes seem to be a little easier than others. Some dial right in and some take a little more time.

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Hi Guys,

 

When you balance your carbs they will usually always be a tad smoother when you reconnect the balance/crossover tube. I would never let anyone balance my carbs at less than 3500 rpm. I have seen a couple of shops balance at 2500 and the carbs will always be off at 3500-4000 rpm. You fly closer to the 3500-4000 rpm. 2500 is for idle. Tell a shop if your capable of balancing at 2500 then you can do it at 3500-4000. Once you get used to doing carb balancing then any rpm is just as easy to do. I will state for the record that some planes seem to be a little easier than others. Some dial right in and some take a little more time.

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Hey Jeremy,

 

Do you have one of these?

Happy carb balance assistant.

I always tell her that if I spin in the prop more than twice she may want to shut it down because I might make the prop unbalanced. ohmy.gif

 

I never let her behind the controls if she is mad at me. laugh.gif

post-3-0-70242300-1308964997_thumb.jpg

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  • 1 year later...

Roger,

1st time with a Synchromate. I did not reset the idle mixture or idle stopo or throttle cable. Just hooked it up and here's what I saw at start up 78 degrees thru runup at 148 degrees. Also, I hooked up to #2 and 4 as REF.....does it matter which side I hook up:

LEFT CENTER RIGHT

2000@4.5

2300@0

1990@4.5

2200thru4920@0 ----this was also max static RPM is that good?

3560@1

2180@5.6

2210@2,5

 

Seems like the vacuum is more to the left at 1900 to 2200, the closer to center from 2300 thru 4920 WOT

Any suggestions for adjustments? perhaps do the mechanical sync first??? Thanks Doug in IL

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Hi Doug,

 

Pick an rpm between 3500-4000 and set the carbs so they are equal. Then go back to idle and use the idle stop screw and set the idle. Either side you hook up is fine.

If the carbs have been synced before then the pneumatic is okay. If they have never been synced or you have worked on the carbs then add the mechanical balance too. The mechanical balance only gets you in the ballpark and is never a substitute for a pneumatic sync.

 

You really don't care about staid rpm as it is slightly different between props. It only gets you in the ballpark. You need to fly it to get a good WOT rpm set.

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Thanks Roger, say assuming the carbs have been set before should I try to lean it a little if I get light to medium brown/black exhaust soot on the belly and on my finger in the stack??? I have idled it a lot, but also a couple flights have been an hour or so and it still looks a little sootied....so should I mess a little with the idle mixture...or am I trying to fix something that isn't necessary?? And could mess up other settings and engine performance???

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