Fun with Jets

1962-1965 Datsun L320 and NL320 forums - The truck that started it all in the US. All 320-specific topics and discussion can be found here.
22350
Posts: 6
Joined: Thu Sep 09, 2021 9:14 am
Car: 1964 320 Datsun truck

Fun with Jets

Postby 22350 » Tue Sep 28, 2021 2:07 pm

Hello everyone. Decided to rebuild my original carb. Took a lot of photos and notes, but when I was getting ready to reassemble it, something seemed weird.

I have arranged all the parts where they came out, but I noticed the the "air inlet jet" appears to be smaller on the secondary. (i have them numbered in the picture)

I am also noticing that the air bleed jets on the primary and secondary side have the holes on top in different places. They are the same size, but one has the hold on the side.
little all.jpg
IMG_0267.jpg
Everything in the following picture is how it came out, but notice how the air bleed jet with the hold on the side is in the secondary and the idle bleed jet has the larger diameter on the primary. Did someone switch those two?
IMG_0258.jpg
thx


User avatar
VStar650CL
Posts: 2899
Joined: Thu Nov 12, 2020 1:25 pm
Car: 2013 Nissan Altima 2.5 SL
2004 Nissan Altima 2.5 S

Re: Fun with Jets

Postby VStar650CL » Tue Sep 28, 2021 3:59 pm

Most of my carb experience is older than that carb, Rochies and Holleys and cable Mikunis, but I can tell you a bit in general. Secondaries have no "idle bleed" because they're closed at idle, and like an afterburner, they're generally dumping more fuel than air when they're open. So their emulsion plumbing is generally small compared to their jetting, while the opposite is true in the primary where fine mixture control is critical at small throttle openings.

22350
Posts: 6
Joined: Thu Sep 09, 2021 9:14 am
Car: 1964 320 Datsun truck

Re: Fun with Jets

Postby 22350 » Wed Sep 29, 2021 9:26 am

B4E1EAAD-1564-441E-A689-2D73819B2FA3.jpeg
B4E1EAAD-1564-441E-A689-2D73819B2FA3.jpeg (118.77 KiB) Viewed 46 times
Pardon my terminology flubs. I have attached a clearer picture that I hope explains my confusion.

My confusion is about the position of the 160 and 220 air bleeds.

22350
Posts: 6
Joined: Thu Sep 09, 2021 9:14 am
Car: 1964 320 Datsun truck

Re: Fun with Jets

Postby 22350 » Thu Sep 30, 2021 2:26 pm

so I looked in the shop manual and there was info there. I had looked in the parts catalog and there was nothing.
2021-09-30 14_21_11-carb set up.pdf - Adobe Acrobat Pro DC (32-bit).png
I have the answer.


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