A Project Is Brewing...

[rossiz]

some wax.

[Patcon]

Will that keep it from oxidizing? How often do you have to reapply it?

[Mark Maras]

Hey Geoff

WOW The SUs & everything are beautiful inside & out. Tuning these on Lilith should (hopefully) be easy. When is the set-up going to be installed? Are you going to install the new elec. set-up beforehand too?

Rapid progress(outsiders point of view) & excellence are difficult to achieve at the same time. Good job on both.

Mark

[siteunseen]

This works good too.

 

[Freez74]

Beautiful job!

[Captain Obvious]

Nice polish job! I have a concern on the suction pistons though... On the pistons, you removed material around the entire bottom corner of the piston and I'm worried that you have created two small pathways for air to go around the venturi instead of over it.

 

The original sharp corners around the sides of the pistons provide somewhat of a seal to encourage air to flow through the center (recessed) area of the piston where the nozzle is. When you rounded that corner all the way around, you provided two additional parallel paths for air to flow past the piston without passing over the nozzle venturl.

 

I'm no expert, but I'm concerned that you might run lean at low throttle positions because the airspeed at the nozzle will be reduced. At higher flow rates when the piston is pulled higher it will be less of a contribution, but at very low flow rates you might see an effect.

 

Let's hope I'm just a worry wart. 

[rossiz]

i hear what you're saying cap'n - the mod was shown on the 'just su' video and i figured they knew what they were doing (not that i do...) 

we'll see how it goes eh?

 

i've got a 2-sensor wideband that i'll be installing to check both carbs independentyly, which should be informative for checking the sm needls as well.

[Captain Obvious]

Yup. Hope it works! I don't remember the comparison between the SM's and the stock needles, but I do believe the SM's are richer across the board. Even if you would be running a little lean with the stock needles, the SM's wouldn't be as much of an issue.

 

And again, the farther you are from idle, the less of a contribution those fillets would add.

[siteunseen]

Which balance tube are you using?  I want to simplify mine, like yours.  What are those 2 nipples behind the front carb for?  Vacuum advance and what else??? 

 

EDIT:  Okay, I see now on ztherapy.com, it's the Euro tube.  I think I figured out those nipples, I'm guessing they are '70 carbs.

 

2nd EDIT: They're on the intake, not the carb.   I woke up too early.

I have the E88 intakes, they're not on them.  Yours, maybe E34?

Edited May 19, 2015 by siteunseen

[Captain Obvious]

Those intake manifolds are from something that used to run flat top carbs. Either 73 or 74. Don't remember the numbers...

 

Four of the holes (two on each manifold) are blind and were used to mount the idle mixture tube. The two nipples (on the front manifold) were used for some of the extra vacuum plumbing that went with the flat top system.

[rossiz]

actually, it's an ersatz euro tube... i couldn't find one, so i made one by cutting, filling & cleaning up a donor (thanks again mark maras!). i left the vacuum port on the top of the balance tube for a gauge, brake booster will attach at the end of the log. here's a link to the work:

http://www.classiczcars.com/topic/51242-looking-for-a-balance-tube/

 

the intake manifolds are N33 which came w/the carbs and i believe the whole setup is from 3-screw '72... all the extraneous vacuum ports will be filled as i have no use for them. 

[Mark Maras]

Siteunseen

 The balance tube is from an early 71.