Float level advice, please.

[Captain Obvious]

So my inserts were made on a lathe (because I have a lathe and I'm not afraid to use it), but you could probably find something store bought that would perform the same task.

My thoughts on that are... Brass has higher density than steel. And steel has higher density than aluminum. I used brass because it was the highest "bang for the buck" in the density department meaning that the insert could be made smaller to get the highest mass (as compared to steel and aluminum). If for some future reason, the ballasts I put in there are deemed too heavy, I can switch out to steel or aluminum in the future to lighten them up.

I'd be happy to talk on the phone about your frustrations. If you want, send me a PM and we'll do some of that. I feel your pain. 

[Duffman]

Adding my 2 cents, I believe that CO created a great solution for the wayward float!  The "bloat" works great on my setup, and I have no calibration issues like you are running into, Madkaw.  I highly recommend the concept!  

Bruce, I like the new screw idea!

[madkaw]

Just got off the phone with my car friend and PHD physics guy. His thought was as long as you had a reasonable amount of fuel in the float bowl, the Venturi will pull the fuel pass the jet fine . It’s more critical that the jet and needle are the same on both carbs than it is to get max amount of fuel in the bowl . I like the idea of the floats being more level , but it doesn’t add any more fuel to the bowl ( volume ) . I think getting the float needle to sit in the float tang properly is important too - especially with these flat tipped float needles

[Captain Obvious]

I believe the importance of getting the float level-ish is to prevent it from hitting the underside of the lid.

Here's a description of the problem I've had. This is what was happening that made me add some weight.

Level is too low, adjust the tang.
Level is still too low, adjust the tang some more.
Level is still too low, adjust the tang some more.
Bam! Carb overflows.

At that point, the float is probably hitting the underside of the lid, or maybe even or the inside of the bowl if the angle is extreme enough.

[Duffman]

I had the same issues as CO, multiple adjustments and still too low until I reach a point where it overflows!

[PermaZ]

Hi guys! I’m new here😊

 

I read this topic with great interest. I have the same problem with my carbs as I can’t get the float level high enough. I’m aiming for 23mm below the lid but it stops at approx 30mm with the tang bend far down and the float high up at a «weird» angle. My car is a ‘72 (euro car) but it is kind of a crossover with lots of parts from the ‘71 shelf so it has the four screw carbs with two ears with equal length. If I have got this right this should be two short ears with two short valves (18,5)(?). The ears looks long but the pivot points are quite high up. This is definately confusing. 

I have tried to come up with a solution for this but no luck so far. I’m thinking of adding weights to the floats as some of you have done. Does anyone has any experience with this over a longer period of time? Is this a good solution? And what’s the «ideal» weight?

[Captain Obvious]

6 hours ago, PermaZ said:

I have the same problem with my carbs as I can’t get the float level high enough. I’m aiming for 23mm below the lid but it stops at approx 30mm with the tang bend far down and the float high up at a «weird» angle. My car is a ‘72 (euro car) but it is kind of a crossover with lots of parts from the ‘71 shelf so it has the four screw carbs with two ears with equal length. If I have got this right this should be two short ears with two short valves (18,5)(?). The ears looks long but the pivot points are quite high up.

First, some answers... For the 71 four-screw lids, You should be using the 18.5mm long valves. So what you are using there sounds fine.

The target float level for the 71 lids is 20mm below the lid, but I believe anything close (18-22) should be fine.

When I went through the same thing, the only solution I could come up with was to add weight to the floats. This 4g brass plug threaded into the side of the float worked well:

Edited July 8 by Captain Obvious

[nidriver]

I have a 1972 iwth a similar problem and the two different lenght ears. If you had to summarise the approach - and i wanted to just buy a threaded piece to use - what do i do/

 

Do i put a brass screw 4g weight (of whatever dimensions roughly you have there) into both floats?

How much do i sand off and is it at the bottom or top or sides?

 

And finally - have you put these in your car and has it solved the issue?

[siteunseen]

I am using two long armed lids on my '72's, basically they are 3 screw carbs with the early 4 screw configuration. I put a rear lid and valve on my front carb with great success. 

From ztherapy.com...

The Float Chamber Lids came in three styles. The float pivot points are called ears.  They came long or short.  All 70 carbs had two long lids.  71-72 had one long, one short (the short one goes on the rear carb).  1969-Jan 1970 float chamber lids were round with 4 tabs for the hold down screws.  This is a result of Datsun raiding the parts bin and using leftover 2 litre Roadster parts.  The Z 4 screw body IS the 2L roadster body with the vacuum tap moved.

[w3wilkes]

3 hours ago, siteunseen said:

I am using two long armed lids on my '72's, basically they are 3 screw carbs with the early 4 screw configuration. I put a rear lid and valve on my front carb with great success. 

From ztherapy.com...

The Float Chamber Lids came in three styles. The float pivot points are called ears.  They came long or short.  All 70 carbs had two long lids.  71-72 had one long, one short (the short one goes on the rear carb).  1969-Jan 1970 float chamber lids were round with 4 tabs for the hold down screws.  This is a result of Datsun raiding the parts bin and using leftover 2 litre Roadster parts.  The Z 4 screw body IS the 2L roadster body with the vacuum tap moved.

I don't know... Did the 2000 or 1600 Roadster have twin Hitachi's or just a single?

Edited September 8 by w3wilkes

[Captain Obvious]

On 9/7/2024 at 5:50 PM, nidriver said:

I have a 1972 iwth a similar problem and the two different lenght ears. If you had to summarise the approach - and i wanted to just buy a threaded piece to use - what do i do/

Do i put a brass screw 4g weight (of whatever dimensions roughly you have there) into both floats?

How much do i sand off and is it at the bottom or top or sides?

And finally - have you put these in your car and has it solved the issue?

I have performed this procedure on a few carbs, but I think only one set has seen the road. Reports are that set worked well.

So I made a custom threaded piece of brass. Maybe you could find something generic instead of making something special. 

I put it in a position where it did not interfere with the hinge molded into the float, and I did not want to put it upwards into the bottom of the float because of gravity.

Beyond that, I tried to put it into a "fail-safe" position on the float such that if it starts to work itself out of the float, it would hold the float closed instead of holding it open. Figuring that a float level too low would cause the engine to not run, while a float level stuck open could cause a fuel spill.