Restoration of BringaTrailer 240z - HLS30-35883

[Captain Obvious]

23 hours ago, inline6 said:

It seems like the only thing it could effect would be fuel flow, and that with the level lower, it would "less".  Are there other effects you are can think of?

The belief is that the mixture will be affected because the lower the bowl level, the higher the fuel would need to be lifted (by the venturi vacuum) in order to be pulled up past the needle. Physics dictates that the theory has merit, but I'm not sure about the magnitude of the effect.

In other words... I agree that it would take more energy to lift the fuel higher, but I'm not sure I agree on whether that increased amount of energy is negligible or not.

I do know that I have run cars* until the bowls get sucked down so far that they are nearly dry. And the engine seems to run just fine right up until the very end when the engine stalls due to lack of fuel.

 

* and generators and lawn mowers, etc

[inline6]

So a quest for the highest acceptable fuel level in the chambers may not have any value at all!  Perhaps I can investigate that a bit with the wide band in coming months.

[siteunseen]

Are you setting the float valves with the lids upside down like the "Just SUs" dvd or right side up and float hanging?

[inline6]

4 hours ago, siteunseen said:

Are you setting the float valves with the lids upside down like the "Just SUs" dvd or right side up and float hanging?

With the "wet set" method, I was setting them in the installed state, adding gas through the inlet to the float chamber.  I was setting the height of the fuel (as seen by looking at the translucent nylon tub attached to the float chamber outlet) to 20 mm below the casting separation line of the chamber and the lid.

I switched to setting at 14 to 15 mm between the bottom surface of the float chamber lid to to the top of the metal portion of the float.  I did this by cutting and grinding 2 3d size trim nails - one to 14 mm in length and one to 15 mm in length.  Using needle nose pliers, I hold each and place them vertically aligned between the float and the roof of the chamber lid.  I hold the float pressed against the nail, pinching the nail (vertically aligned) against the roof... and I blow into the fuel inlet.  Using the 15 mm nail segment, air can flow from the inlet past the needle valve.  Using the 14 mm nail segment, it cannot.  

I used this method with the rear carb only.  I did this yesterday.  Today I started the car and the fuel did not gush out of the vent in the chamber lid.  I did not run it long or do a test drive.

FWIW, this second method is what I always used for my other Z when it had SU's on it.  I never had problems with either fuel overflowing or performance, for that matter.

Edited Wednesday at 02:22 AM by inline6