Hey guys , I guess I’ve been away from carbs too long and now I can’t work on them . A customers car that hasn’t really run yet since rebuild . Trying to set my float levels and using a float sync tool to help assist . The problem I’m having is that I have one carb that wants to be ole faithful . Even if I adjust it for a low fuel level it will eventually overfill. 
I am using a Holley Black fuel pump that is rated for 4-7 psi . I also installed a Mr Gasket inline fuel pressure regulator set at 2psi . I had an extra needle and seat laying around and swapped it out , no difference . The carbs were lightly rebuilt with new needle and seats from Z Therapy . 
Not sure  what to try next. The front carb seems to be doing fine and holding a certain level. I was considering swapping parts from front to back and see if the problem follows .
 

Any thoughts ? 

So those carbs are the 72 three screw versions. They are supposed to have different needle valves in front and rear. Do you know what Ztherapy put in them?

The struggle is real:

https://www.classiczcars.com/forums/topic/55190-float-level-advice-please/?&page=5#comments

 

11 hours ago, Captain Obvious said:

The struggle is real:

https://www.classiczcars.com/forums/topic/55190-float-level-advice-please/?&page=5#comments

 

Thank you for the link . I should have known that there would be an extensive discussion here on this site ! 
The idea of a float that is hitting the wall had come across my little brain while dicking with this . The float metal structure actually looks bent to one side . Maybe I will swap floats from front to back and see what happens . I don’t think I have any spares . 

Glad to (try to) help. I'm actually planning to be messing with floats later today.

Call me. 

So today I went for a pleasant 90 mile trip to meet with a fellow Z'er who had a crucial part for me . He said he found an extra float for a SU in his Weber stuff. Believing that the float was the issue I was happy to find one and try it out. 

So I noticed that the tang was longer on the replacement . I also noticed how flat the tang was compared to mine that was bent straight up it seems. I set it using the 'blow thru the needle and seat method. When I put fuel to it the fuel level actually stop rising and didn't overflow. It was too low so I proceeded to tweek it . And wouldn't you know it overflowed -SH!T

So I made another adjustment . Long story short I come to realize that if I empty the bowl by completely draining it( usually when I remove the float sync tool) , the needle and seat had a harder time stopping the fuel then when there was fuel left in . I can only presume that the fast filling empty bowl made it harder for the valve to stop the incoming fuel. So I started making float changes by just removing the lid and leaving the float sync tool in place .  I was able to get pretty close to the 23mm from the top of the lid. 

When I moved on to the front carb I saw another mangled float tang -ugh.

To be continued 

Edited August 24, 20222 yr by madkaw

 I can't imagine the tangs got that way accidently but I can't imagine why someone thought that would work. If my memory is correct @siteunseen has dealt with float tang angles in the past.

 

Yeah I set mine like the DVD from ztherapy shows, however the DVD uses Grose valves which are much stiffer than the new needle pin valves they sold me. I turned the lids upside down to get the 9/16" space the DVD shows. My tangs looked like the ramps Evel Knievel used to jump the Bellagio fountains. I finally got wise/bored and put the floats and lids on top of a glass, hooked up a low psi fuel pump and set them to 23mm down. Then the tangs look like speed bumps instead of ramps now.

I believe it was the fountains at Caesars now that i think about it. I's just a puppy when I saw that. 

Edited August 24, 20222 yr by siteunseen

I would put the Mikuni HSR very high on my list to swap from SUs.  Amazing throttle response, less then an hour install time.  You can retain PCV, stock manifold, stock fuel rail etc.. The most advanced carbs on the market (their claim). 

 

https://i.imgur.com/fpoMjbU.mp4

 

https://forums.hybridz.org/topic/133136-mikuni-hsr-45-install/?fbclid=IwAR0KDwLXhsJxkpSJG7l_Bg00K_FcIVCeDNoUJsemkILDP_W7sFJu1JOA2sU

 

http://www.v-performance.com/products/air_fuel.html

On 8/24/2022 at 12:20 PM, siteunseen said:

Yeah I set mine like the DVD from ztherapy shows, however the DVD uses Grose valves which are much stiffer than the new needle pin valves they sold me. I turned the lids upside down to get the 9/16" space the DVD shows. My tangs looked like the ramps Evel Knievel used to jump the Bellagio fountains. I finally got wise/bored and put the floats and lids on top of a glass, hooked up a low psi fuel pump and set them to 23mm down. Then the tangs look like speed bumps instead of ramps now.

I believe it was the fountains at Caesars now that i think about it. I's just a puppy when I saw that. 

Hey Cliff ,

if you have any pics of those tangs or maybe sketch out the shape of your tangs that worked . I’ve been at for days now and actually bought another set of SU’s so I had more floats to choose from . 
I got the front one nailed , but it’s seems whatever I do to the rear one comes up short .

 

On 8/24/2022 at 3:14 PM, duffymahoney said:

I would put the Mikuni HSR very high on my list to swap from SUs.  Amazing throttle response, less then an hour install time.  You can retain PCV, stock manifold, stock fuel rail etc.. The most advanced carbs on the market (their claim). 

 

https://i.imgur.com/fpoMjbU.mp4

 

https://forums.hybridz.org/topic/133136-mikuni-hsr-45-install/?fbclid=IwAR0KDwLXhsJxkpSJG7l_Bg00K_FcIVCeDNoUJsemkILDP_W7sFJu1JOA2sU

 

http://www.v-performance.com/products/air_fuel.html

Well it’s not my car or I would consider that option 

They need to look like these. 

 

You say "comes up short", could you not stack enough washers under the valve to raise it?

 

Edited September 6, 20222 yr by siteunseen