Bending float tab direction - 3 screw SU

[NVZEE]

10 hours ago, Stanley said:

For the water jar method, will the float sit the same in water as it would in gasoline?

That question's been around since the water method has been used. Water is the baseline for specific gravity at 1.00; gasoline s.g. varies but is about .74. So water density is about 25% higher, which is why gas floats on water. The float would also sit higher in water. Someone with a dial indicator could compare the two and come up with a more accurate number for this.

https://www.sunocoracefuels.com/tech-article/specific-gravity-matter

Oh ... and witches, of course ?

Edited October 31, 2019 by NVZEE

[240260280]

I did the calculations a while ago for a test rig using a column of water. The pressure down on needle to open it vs density for floating to close the needle was approximately the same ratio as if you used a column of gasoline or water of the same length.

The heavier water column pushes needle valve more, but the denser water also pushes the float up with more pressure than gas.

Maybe someone else can double check this to validate.

 

Edited October 31, 2019 by 240260280

[jalexquijano]

Why do you have to do all these lab tests and analysis. Isnt it simpler to stick the float sync tubes to the drain plug and measure 23 mm from the lid?

[240260280]

Yes it is simpler on SU's with a clear tube and 20mm.  I used the water tower method on triple Webers to improve precision and balance.

SK Racing and Mikuni have adjustable float height with is best solution.

[jalexquijano]

Does the fact that my engine is refurbished to 2.6 liter with oversized pistons matters?

[siteunseen]

4 hours ago, Mark Maras said:

 I can't recall ever hearing about using a hill to determine float levels and can't imagine how it would work.

I bet he's remembering my post on how I came to realize I had almost no fuel in my chambers. I had starvation on my front carb driving up Mt Cheaha. I set my floats as the Ztherapy dvd suggested but they were using Grose jets when that video was shot. You can't do them that way with these needle valves.

Just a guess though. I'm with you Mark, can't imagine setting proper levels going up a mountain. 

 

[jalexquijano]

You are right. I did checked on one of the hoses clamped to the airtex 8012s electric fuel pump and even though its not dripping any fuel its a little bit worn. Should i worry about this?

[siteunseen]

This looks a bit suspect to me. Anyone one else see the kink or pinch?

You have plenty of extra hose. Cut that end off and reattach, IMHO.

Edited November 6, 2019 by siteunseen

[kully 560]

I just changed my floats as 1 was going bad it had gas in it .  I also have gross jets and spoke to steve yesterday at z therapy about the setting measurement  and he told me .55" down from the lid with no gasket. he also said gross jets and needle valves are the same measurement !! I asked him about the bridge measurement and his reply was that this is another way of doing it but very hard to do as the gas in the bridge hole is hard to see it is like looking into a mirror. so I set mind at the .55" down from the lid and it seems to run good with just a little stumble off line but I think I may be a little lean on the back carb as I pulled out the plugs today to check . so I gave the back carb a 1/4 turn down more and re sync. will test tomorrow as it rained all day today. but the .55" seems to be fine. try it nothing to lose. PS my front carb is turned down 2- 3/4 turns and the rear is turned down 2-1/2 turns as of now.

Edited November 6, 2019 by kully 560

[Mark Maras]

2 hours ago, siteunseen said:

This looks a bit suspect to me. Anyone one else see the kink or pinch?

You have plenty of extra hose. Cut that end off and reattach, IMHO.

 Yup, looks iffy to me. I'm not a big fan of rubber fuel lines in contact with the body. In the pic above it looks like the hose is too long. Cut it short enough to eliminate the body contact.

[Mark Maras]

1 hour ago, kully 560 said:

I just changed my floats as 1 was going bad it had gas in it .  I also have gross jets and spoke to steve yesterday at z therapy about the setting measurement  and he told me .55" down from the lid with no gasket. he also said gross jets and needle valves are the same measurement !! I asked him about the bridge measurement and his reply was that this is another way of doing it but very hard to do as the gas in the bridge hole is hard to see it is like looking into a mirror. so I set mind at the .55" down from the lid and it seems to run good with just a little stumble off line but I think I may be a little lean on the back carb as I pulled out the plugs today to check . so I gave the back carb a 1/4 turn down more and re sync. will test tomorrow as it rained all day today. but the .55" seems to be fine. try it nothing to lose. PS my front carb is turned down 2- 3/4 turns and the rear is turned down 2-1/2 turns as of now.

 If your plugs look good and the only problem is a little stumble off the line, you may want to run heavier wt. oil in the dampeners. Nissan recommended 20 wt. I always used ATF with good results.

[kully 560]

hi mark my first 3 plugs looked good but the rear 3 plugs looked a little lean. I will try the car today after I turned down the rear carb a 1/4 turn down more. I was not aware of the 20wt oil that Nissan recommended. I thought fork oil or 3-1 oil was good, I think it is like 8 weight oil but will give the 20wt oil a try if my stumble is still there.