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I've been working on a new product for the last six months that I'd love to get some feedback on. I've always known getting the floats in SU's set properly, and knowing for sure they were set the same in both carbs was important, but the method of doing so always seemed imprecise and less than elegant. I developed Float-Sync to know precisely where floats were set and have a visual reference, without removing the float bowl lids. On three screw SU's, there's a threaded plug in the float bowl that can be easily removed to substitute Float-Sync.

The level of fuel in the float bowl dictates the level of fuel in the jet nozzle. This is a big deal for SU carburetors because the fuel level in the jet nozzle directly impacts engine performance. When the engine is running, a vacuum is created in the SU carburetor venturi that pulls fuel out of the jet nozzle, mixing it with air and drawing it into the engine. If float levels are adjusted too high, fuel puddles at the top of the jet, allowing too much to be drawn into the engine, creating a rich condition. If the float is adjusted too low, it's harder to pull fuel out of the jet, creating a lean condition.

A rich condition can cause plug fouling, poor fuel economy, gas fumes, diluted crankcase oil (contributing to blow by and reduced engine protection), and in extreme cases potential for an engine fire. A lean condition can cause the engine to stumble, back-fire, ping and run hotter than it should, creating the potential to burn valves.

Float-Sync allows you to see precisely where your floats are. You can see the fuel level, with the engine running, throughout the entire RPM range… all without opening the float bowls. You will never wonder again if your floats are adjusted correctly.

I'd be interested in your feedback and suggestions. I listed a few sets for sale on eBay yesterday to gauge interest. Thanks

 

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Edited by Randalla
typo
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That's pretty neat. I'd like to understand how that works better. I've used clear tubing to those bowl screws and the 23mm mark from the lid to get close. My next step is turning the knobs down 10 rounds and looking for fuel in cuspid of the nozzles.

Please elaborate on your device. 8^) 

I'd be interested.

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Setting floats by removing the float bowl lid and measuring the distance between the lid and top of the float is imprecise at best, because there are so many other variables. Using a hose as you suggested is another option, but for me it was nearly impossible to do both carbs simultaneously without having two extra hands. With the Float-Sync units screwed into each outlet you can visually see exactly where the level is inside the bowl, hands free. An added bonus is that you can view the level in the site glass as you run RPM's up to assure the levels don't change. Each unit has a pair of fuel grade O rings to seal against leaks. No need for a wrench to install, you can turn it in by hand and it will not leak.

To make float adjustments, you remove the four screws on each float bowl and lift the cover off with float attached. The metal tabs on the floats can be bent slightly up or down to change the fuel level in each bowl. With the float hanging below the cover, bending the float tab down will raise the fuel level in the bowl. Bending the tab up on the float will lower the fuel level. To observe how your adjustments have changed fuel level in the bowls just replace and secure covers, then restart the car to inspect fuel levels. You'll need to be patient as it may take a few attempts to sync float levels precisely.

 

 

 

Edited by Randalla
typo

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Randalla has provided me a set to try out, works great! You can calculate the 23 mm down from lid as being the same as 14 mm up from the base of the tube. As Randalla states, you can adjust both carbs at same time, very convenient!

Sent from my HP Slate 7 Plus using Classic Zcar Club mobile app

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looks nicely made - is the tube glass or plastic?

is there a cap for the top or is it open to the air?

i'm assuming you put these on to test and then take them off - or are they a permanent install?

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These look great Randy! I've cobbled up my own but nothing this slick!

Ok fellow innovators, to me the real holy grail is to contrive a method to adjust the float levels without the trial and error madness of removing the lid and bending little miserable tabs. That together with an external indicator of the fuel level (see post #1) would be pure nirvana..... 

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I installed a holley four barrel on my boat. It has an external adjustment for the float level with a locking ring. Not really sure how it works but is really nice...

On an SU, It would just about have to lower or raise the fuel inlet. That seems like a lot of engineering...

Or maybe add a pivot point and bar and the adjustment screw moves the pivot point instead...

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Originally I had planned to use glass until someone suggested the units would be useless if someone dropped them. The sight glasses are made of Acrylic. Yes, they are intended to be used as test devices rather than a permanent install. Covering the end of the of the tubes with a cap won't allow the gas to rise in the sight glass to the same level in the bowls because there is no way to vent the pressure created. I too would love to solve the problem of removing the lids to check and adjust floats but that seems an impossibility, LOL.

Edited by Randalla
typo

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I purchased a set but haven't received. Looks very useful. While I will continue to adjust floats by removing the domes, turning the nozzles down 10 turns and setting the fuel level at the top of the nozzle, it will be nice to test the result with this device....I think.

Regarding adjusting the floats without removing the lids and bending tabs....I have been trying to think of a way to do that for some time but alas no breakthrough. To me, even if you had to remove the float...coming up with a more precise way to move the tab with a set screw rather than bending the tab would be great. On my way to adjusted floats I go through multiple cycles of bending too much, reinstalling, bending too little, reinstalling, etc, etc.

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Thanks for your purchase Jonathan. Please e-mail me and let me know how you like them when you've had a chance to try them out. Your set was shipped yesterday.

Edited by Randalla
typo

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I connect clear tubing to the bottom of the float bowl, use a remote starter with plugs out to get the float bowl filled up. Empty the bowl and hose between each adjustment. rinse repeat until level is where you want it. Do the same with other carb. I can get them within 1mm of each other.

On the three screw carbs, I will put a longer fuel hose from the fuel rail to the float bowl lid so you can twist the lid clear when taking it off.

The four screw carbs can be done using the stock length hose from the fuel rail since the lid just lifts straight off.

 

 

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7 hours ago, Darrel said:

On the three screw carbs, I will put a longer fuel hose from the fuel rail to the float bowl lid so you can twist the lid clear when taking it off.

That's a darn good idea!  I have to unhook the hose each time. :blush:

New hoses for me.  Thanks

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If any of you are interested in a set, Private Message me. I can do a little better on the price, outside of an eBay sale. Thanks for all the feedback received so far and specifically to Duffman for the user review.

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Have not yet tried that siteunseen. Should not affect the way the car runs because the float bowl lid is vented anyway. Not sure about them fitting behind the stock air box, but I will check and report back. My car is in offsite storage at the moment.

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Great idea using longer hoses from the fuel rail to the banjos while setting the floats. It took me about ten tries for each carb to get them where I wanted, using  sight glasses, (2mm higher for rear carb btw) and had to pull the hoses off and replace them every time. At least the levels tend to stay put once they're set.

If you're concerned about gas running out of the sight glass and/or the vent, and it might in the course of adjusting the levels, you can run some tubing from the vents into an improvised catch can.

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Sold the first 4 sets posted for sale on eBay in the matter of a few days. I posted a few additional sets this morning if you're interested.

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The level of fuel in the float bowls is the first step to be taken before making any other fine adjustments to optimize “runability” (other than valve adjustment). In my experience Float-Sync gets you to the baseline as quickly and accurately as possible.  

I learned, like most of us, the way to set float levels is to remove the float bowl lid and measure the distance between the lid and the top of the float when the cover is inverted. What I have since learned is how imprecise this approach actually is (in terms of optimizing engine performance) because of so many variables. Some of those variables include whether the carbs are being run with or without float bowl gaskets, how many turns down the jet nozzles are set, if the float valve is fully opening and closing, if the float bowl lid has short or long ears and if floats are intact and their buoyancy is the same in each float bowl and I’m sure there are a number of others. For those more fluent with SU's than I, what other variables am I missing...Bruce Palmer? 

Edited by Randalla

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GREAT INVENTION! I wonder if this is something that you could market through the multiple datsun facebook groups, probably would get lots of sales.

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On 30/6/2016 at 6:22 PM, Randalla said:

I've been working on a new product for the last six months that I'd love to get some feedback on. I've always known getting the floats in SU's set properly, and knowing for sure they were set the same in both carbs was important, but the method of doing so always seemed imprecise and less than elegant. I developed Float-Sync to know precisely where floats were set and have a visual reference, without removing the float bowl lids. On three screw SU's, there's a threaded plug in the float bowl that can be easily removed to substitute Float-Sync.

The level of fuel in the float bowl dictates the level of fuel in the jet nozzle. This is a big deal for SU carburetors because the fuel level in the jet nozzle directly impacts engine performance. When the engine is running, a vacuum is created in the SU carburetor venturi that pulls fuel out of the jet nozzle, mixing it with air and drawing it into the engine. If float levels are adjusted too high, fuel puddles at the top of the jet, allowing too much to be drawn into the engine, creating a rich condition. If the float is adjusted too low, it's harder to pull fuel out of the jet, creating a lean condition.

A rich condition can cause plug fouling, poor fuel economy, gas fumes, diluted crankcase oil (contributing to blow by and reduced engine protection), and in extreme cases potential for an engine fire. A lean condition can cause the engine to stumble, back-fire, ping and run hotter than it should, creating the potential to burn valves.

Float-Sync allows you to see precisely where your floats are. You can see the fuel level, with the engine running, throughout the entire RPM range… all without opening the float bowls. You will never wonder again if your floats are adjusted correctly.

I'd be interested in your feedback and suggestions. I listed a few sets for sale on eBay yesterday to gauge interest. Thanks

 

IMG_1087.JPG

IMG_1148.JPG

IMG_1161.JPG

Are you selling this set at the moment? Im interested in one of them

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6 minutes ago, jalexquijano said:

Are you selling this set at the moment? Im interested in one of them

I have a set of these, they came highly recommended. I have not had a chance to use them yet. I believe, from my research, these and a colortune should make it possible to put a great tune on the SU's. I would be glad to do a review once I find the time to tune the carbs. 

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There is a similar tool to set triples I saw somewhere on a JDM site. I will search and return.

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