Captain Obvious

That will show up on a clear tube wet test if he uses the fuel pump to fill the bowls.

No. You should assume that your .dry 55" measurement got you (hopefully) close to your target, and do a REAL fuel level test using the clear tube method. The mechanical .55 is just to get you in the ballpark. Sometimes it works straight out of the box without subsequent adjustments, and sometimes it doesn't. You need to verify the level on the car with fuel in the bowl, not dry on the bench.

I'm thinking if they are 50% better, he needs to the same amount of brushing again and then they'll be 100% better, right? Math.

I think there is some wood in there, but put it this way... Nobody should worry about termites.

I'm having a hard time reconciling these two statements: About the only way to get fuel to pour out of the carb mouth is for the float bowls to overflow. So if the float levels are withing spec, I'm having trouble correlating that to fuel coming out of the front of the carbs. Are you saying that you have checked the bowl levels right WHEN the problem is occurring and they are in spec? Even while there is gas pouring out of the carb mouths?

Me too.

Not sure about the 240, but the 260-280... Easy-peasy:

Exactly. It's getting normal lots of places. That's the vaccine at work. Every person who gets the vaccine makes things better for all of us. But it's no time to let up. We're not at herd immunity yet, and mutations are still a risk to everyone. Even the people who have gotten a vaccine.

Stud!! I got that part right! Wrong hair color though.

I believe those limiter bolts are just an attempt by Nissan to keep you from turning the knobs "too much". Kinda like the limiting caps on carburetor adjustments where they don't want you messing with them "too much". And in 72, they took that idea even further limiting the adjustment even more. Those are the funky large knobs on the underside of fhe 3-screw round tops.

Agreed! And I find it's the same way with people you've never met. For example... This is my mental picture of you:

Love it! That's a fantastic scene. Absolutely fantastic.

Thank you Mr X. Happy to hear you took the step to become part of the solution by removing yourself from the mutation pool. I want to stamp this thing out, and as long as there are enough hosts out there for this bug to propagate, we're at risk. So for all you people who cheer that fact that restrictions are being relaxed. Woo hoo! It's awesome, isn't it? All you people who like the fact that the numbers are going down. Yay! That's fantastic, right? Well if you like the results but have not gotten a vaccine yourself, you're setting us up for another round when this thing mutates and pokes through the vaccine. If you like the benefits, become part of the reason things are getting better. Don't rely on your friends and neighbors to fix the problem for you. Everybody's got an agenda, right? My agenda? I don't want to go through this ever again. I want life to go back to normal. I don't want to wear a mask. I miss seeing my Z friends and I guess I'm willing to go out on a limb a little bit for not just myself, but for other people as well. We're all in this together. So go get a vaccine! Get yourself out of the pool of mutation donors!

Smart man!

Bloats. Love it! So yeah, I'd be happy to have you test the bloats. It would add one more data point as to the validity of the modification. I'll send you PM!

Hahahaha!!! As a matter of fact, I've been informed (by the wireless carrier) that my old phone won't work for very much longer and they are sending me a new phone. And get this... The new one is a 4G flip phone!! LOL! I read the reviews for the new phone and they're terrible... Everyone says the screen is really small and the apps that you can put on it are crappy. Well duh. Sounds perfect. And speaking of my old phone... Now it's getting hot when I charge it and the back is a little bulgey. So I won't need any blankets to keep warm. The lithium fire will be plenty warm. Now I just need it to last long enough for the new replacement to get here.

Me too, but the on-road analysis might take a while until they end up on a car. You want me to send you the "heavy-duty" floats and you can try the whole thing out on your car? I'm actually comforted by the fact that someone thousands of miles away with different gas is having the same issues. Just another data point aiming at changes in the gasoline formulation.

I'm hoping!!!

Nice analysis. The geometry of the real system is definitely more complicated, but I think your simplified theoretical example is good enough for discussion here. As for the float shape, I think the conical tip may simply be to try to assure the float doesn't hit the inside of the bowl as the float tips beyond neutral. Despite that cone tip though, you can tip the 72 long ear floats so far up that you will hit the inside of the bowl. But the 72 long ears were an afterthought. So one might ask... "Why don't I just keep bending the tang down further to get the fuel level up?" My non-expert answer would be twofold: First, if you bend the tab down so far that the float contacts the underside of the lid, you're screwed. Second, even if you don't have to bend the tab down that far, you can end up on what I'm calling "the downhill slope" of the tab. By that, I mean... You have crested the top of the arc where the needle valve tip contacts the tab. And because of that, much of the force on the valve tip is actually to the side instead of straight up. It kinda pushes the valve tip to the side instead of up. Everything about the system indicates they wanted the floats to be close to neutral tilt. Doesn't have to be exact, but not to fat from neutral.

And just to make sure that my "in a glass" test method was valid, I tested again using the more traditional method with a piece of clear tube off the fuel nipple at the bottom of the bowls. Here's my rig: Here's the result for the rear bowl:: I did have a WTF moment with the front bowl... I put the fuel in, and it overflowed. I discovered that the float was stuck against the bottom of the bowl casting. Yet another fantastic feature of the long ear 72 design. So I emptied it and refilled while tapping on the bowl with a plastic screwdriver handle. That dislodged the float, and here's the result:

So I tried my ballasted floats today. Short story? They work great. I filed the high spots off the spackle. Not that I really needed to, but OCD does things like that: Then I set to trying them out... After a couple very simple, completely predictable tab bends, here's what I got. I set the level just a tiny bit low because 1) it will come up a little bit when there is a fuel pump pushing fuel, and 2) it will come up the width of the bowl gasket. Front looks like this: And here's the front tilt: And here's the rear after one completely predictable tang bend adjustment. Again, a little bit low on purpose: Here's the rear tilt: Based on the tilts, it looks like I could actually cut down on the weight a tiny bit. I'll make notes for if I ever have to do this again.

I'm hoping to be there. Will probably fly in and won't have my car though. @Dave WM How far up Pike's Peak did you get before you had to turn around?

Gotcha. And if you're running a closed loop system that uses lamdas, you should be able to control the mix good enough that you don't light the cat on fire. Good luck with the TIG. Run pure Argon. I wish I was better with mine, but I'm sure some of the faults are my own... I don't use a dedicated grinder for my electrodes (which is a no-no), and I don't have high-freq start, so I assume that my tips are contaminated before I really even get started. Sometimes it turns out good, and sometimes it doesn't. I'm no welder.

The only thing the shape of the float submerged matters much. I would theorize that you want the tapered nose because it would more gradually slope the pressure on the valve up and also not allow any trapped bubbles stuck under the float. But other than stuff like that, I can't see it mattering much. The problem is, as you mentioned, denser fuel will cause the float to sit higher. A higher float causes the valve to close sooner, and a valve that closes sooner results in a lower level in the bowl. And the issue is that I've had troubles getting the level high enough without the float actually hitting the underside of the lid. You remember this discussion you and I had almost ten years ago? I think this was all related to this same issue: https://www.classiczcars.com/forums/topic/43889-fuel-bowl-level-and-bending-tab-not-working/

Spackle is curing. We'll see how it all turns out! So in the meantime, I had a pair of old round tops here. History is I rebuilt these a number of years ago (in 2011... My how time flies) and ran them on my car for a little while before swapping them out for a pair of flat tops. The point is... I had the float levels on these in spec ten years ago and they've been sitting dry in a box since. In theory, they should still be in spec. Well guess what... Here's the front: and here's the rear: The floats have a neutral tilt when the valves close, but the level is way low. The bottom line is that the only thing that could have changed is the fuel. So I guess that brings up a new question... "OK, so it looks like fuel has changed over the last ten years. Is it going to be like that from here on moving forward, or is it going to switch back at some point in the future?"