I got the Man A Fre running nice, just took it for a test run and all seems good. well, idle and part throttle, the cars not ready for wide open yet. I picked up one of those carb sync tools like the bug guys use and am going to attempt to sync 'em. I have never done this and the thing came new but without directions. I can see common sense would dictate the basics here but, who here that has done it can give me a tip or two? Paul
Your holding it the right way up.It sits on the top of one of the carbs.When air is drawn through the big hole,the small red ball in the tube will float.Adjust the carbs,individually,to get the ball floating at the same level on each one.By adjusting the restriction on the big hole,you can compensate for different size engines etc.
i slightly recall syncing SU carbs on a 240Z and it was a long process. first you had to get all carbd reading the same on the guage that you have. that is obviously what the red ball in the tube is for. first though make sure everything else (timing, jets, gaskets, float level) is correct before bothering to tune or you are just wasting your time. start with bringing all carbs in sync with your guage. you might find that after bringing your carbs in sync on the first round your idle may be higher or lower. bring your idle back to where it needs to be and then sync again. it is a long and laborious job. just keep doing it until it is right. it will proabably take a while. i hope that this helps...i am not an expert on it at all, just trying to give you an idea of what to do. i also don't want you to wreck your engine as i am not certain this is the right way to do this for the carbs you have. sorry that this can't be more informative, i just hopes that it gives you somewhat of an idea of what to do.
Here's the info The lines that got cut off say Syn, making certain float is in same position for each carburetor. If not, repeat Steps 5,6,and 7.
Pick one of the carbs as your starting point and reference. It will more difficult since you have four as opposed to the two that I have. However, after determining which carb will be your main, adjust the idle set screw on the other carbs accordingly. The carb that you use as your reference should create enough suction to get the red marker to "float" about half way up the tube. Adjustments can be made to the Uni-Syn by turning the restrictor (the plate in the center with the spring between it and the body) clockwise/counter clockwise. If you synch one carb and the motor does not drop any RPM's that is a good starting point. When you place the uni-Syn over any other carbs and discover a major reduction in RPM's the carb is out and will need adjustment. It really is a possibly drawn out process because you can actually get the car running at way too high at idle. But, once you get them all the same adjustments can be made easily. Basically back off the original carb's settings, re-adjust the Uni-Syn and start all over until you get the correct adjustments. I hope this made sense and I hope it helps.
And, the first pass is with all linkage disconnected, you want just the carbs at Stage 1. Next hook up the linkake and adjust again for a balance.; this time you will probably need to make linkage adjustments. Another way if you have a friend in a shop is to use an exhaust gas analyzer; that gets it dead nuts on. Always nice to have a vacuum gauge handy, too many carb tuning problems can be traced to a leak. Good luck, the setup looks great.
Make sure that if you pulled any of the choke shafts out of the carbs that you plug the holes they occupied. I've seen many people thrown off while syncing carbs because of this.
The procedures are right, but the tool you've got isn't the best. If you've got low vacum or a built engine with illregular vacum, you need a diffrent synchronizer. I like this one. It doesn't slow down the engine when you throw it on a carb. It's more expensive, but much easier to use. If you've got a sporty-car performance shop they probally stock it. On occasion, you might find it at a very well stocked VW shop. I haven't tried this type, but it's even cheaper than the Uni-Syn and claims to work the same as the other one. Both of these, in addition to the Uni-Syn are available from that fine parts purveyor, J.C. Whitney.
I'm with Modernbeat. This one is 30 years old. I tried your type with no success. I bought this one and was able to get my old Man-a-Fre adjusted. It takes awhile. Every carb adjustment changes the idle speed which changes the cfm of the other 3 carbs. You end up going around and around sneaking up on it. Since you are adjusting only 2 cylinders at a time, the adjustments are more subtle than a central carb system. It may seem like your adjustments aren't doing much. You'll get there.
Lot of good info here. Just remember that the first time you do it, it's gonna take a lot of messing around. Just be paitient. Make sure you do it w/o the linkage hoooked up and get all the carbs pulling the same then hook up the linkage and adjust the linkage only to get the same readings again. Every time you change one of the carbs, the other 3 will react to it.
I found the Holley type on line but, at nearly $60.00 I think I'll try the one I have. all good info so far, and all pretty much how I thought it goes. tell you what though, the setup is a completely different animal than anything I've run before. I've run two one barrels on a Stude flat six, two two barrels on a Stude V8, a tripower on an early Olds, low rise dual quads on on big chev's, tunnel rammed dual quads on big chevs but, this setup sounds different, responds different, looks different and is more of a challenge to setup. I doubt that I will run into another on the street any time soon either! Paul
summit has the uni syn, go to key word search and type in uni syn, actualy ten bucks cheaper other places, http://store.summitracing.com/default.asp?target=department.asp&d=18&x=13&y=10 and LC Engineering has the other, http://www.lcengineering.com/Carburetion3.htm Paul
Here is another carb tuner I read about last week in Auto Restorer. It is called Gunsons Colortune and installs in a spark plug hole. The review, which was done on a 440 Charger, says it also works with multi carb setups. Never saw one. Eastwoods sells at $57.99 so that means it can probably found for less.
286Merc, I'll bet the Colortune is based on mixture, not vacum response. In my book, I always tuned for vacum response first, then dialed in the mixture. I don't thing the Colortune is a good substitute for a vacum gage tuner. The Colortune IS the clear spark plug thingie, right? Lots of motorcycles are tuned by a series of identical vacum gages each hooked up to a vacum port in a carb. That way you have instant comparative values as you twiddle away at your carbs.
We didnt have any fancy stuff when I was in the pits as a kid. Just a vacuum gauge and a calibrated ear was the way the older guys beat it into me. I kind of figured that Colortune thing was more eye candy than useful Jason. But thought it should at least be mentioned. Im not very good with colors anyway and subtle changes go right over my head.
[ QUOTE ] We didnt have any fancy stuff when I was in the pits as a kid. Just a vacuum gauge and a calibrated ear was the way the older guys beat it into me. [/ QUOTE ] That's always worked for me too, and with virtualy no shared plenum the sound from each carb is easy to distinguish. the way it reacts under load and how That sounds, and how it feels in the seat of your pants is as important as anything. the smell of the exhaust can tell you a lot about how it's burning. and the color of the exhaust when you jab the throttle tells you if it's rich or lean. lets see, that's hearing, feeling, smelling and seeing, never used tasting but I bet it would tell you a lot too the tools should be able to provide scientific proof to confirm or deny what your senses tell you. Paul
One thing that always worked for me (and nobody has suggested here) is to set the throttle butterflies with a feeler gauge before hooking up the linkage. Get them all the same with the idle stop screws. That way the carbs are close mechanically before firing the engine and playing with the idle mixture screws. I set the butterflies on my Hilborns the same way. Of course it helps to have rod end linkages with right and left threads on the ends so you can shorten and lengthen those links by simply rotating them. Then lock them with the jam nuts once your butterflies are synchronized.
Sync Meter and Gunsons Colortune...!! The only tools needed for perfect tuning of carbs! I used them on my British cars, Lamborghini, and the Webers on my roadster! Plus I never had to touch the carbs after tuning. They let you know what each individual cylinder is doing in IR (individual runner) set-ups. And for single plenum set ups it alows you to see which cylinders get more gas and which run leaner (this knowledge is for designing and building your own manifolds)! Take your time and set the motor with the Synch meter first then use the Colortune..., Wha Laa! Mark
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