240260280z

1976 Green Datsun 280z

The exact location of 11:30 can be off a tooth if your distributor mount is clocked enough so that you can set the correct electrical timing. Installing the spindle off a tooth or two is a way to fudge the timing if you can't source the correct distributor mount.

The fuel flows through the rail and there is a slight venturi-like scavenging force that draws up on the branches to the bowls. This unloads when the engine is shut off and the fuel stops flowing. For the fuel level, the tilt of the car is not important, it is only that the fuel level is the same height from the top of the bridge for both carbs. The needle and jet fall in place to match.

Consider doing a full splitter plate from the axle to the air dam if you want more performance and less vintage

Alan explains here: http://www.classiczcars.com/forums/open-modification-discussions/51101-cf-l-head.html It is part of the Z lineage and is a less known and almost missing-link like the 4 Cylinder NAPS head.

Nice aluminum rad too...looks like a nice car.

Start at 2 turns down then drive and note how well it performs. Then come down 2 turns and test drive again. Repeat until you pass through a sweet spot. For each test make sure the same flow of air is going in each carb with a flow meter at 2000-3000rpm.

A skim of seal-all at the margin may be a good safety measure.

The hockey puck bushing on the back side of the frame mount for the t/c bushing is the rubber one (the ball and socket goes on the front side of this frame mount location). The poly bushings placed here and over-tightened have broken t/c rods. The rack bushings should be poly for minimal slop as well as the big hockey-puck coupler in the steering column near the brake booster.

It went to junk mail... all is sorted now.

KIDNEY, ANYONE? NOS Datsun Competition L20 head, manifold and 50mm Mikunis | Japanese Nostalgic Car

Read anything from Alan Thomas on this site. He is an expert on this topic and has extensive reference material that he often shares. He is in UK too. Have fun and welcome!

Thanks! I need to collect data first. The 510 will be the test bed because it is faster to change 4 jets rather than 6 on the Z I hope to plot air holes vs Air fuel and experiment to develop a model. I will pull out the drills soon. I hope to compare 4 air holes with 2 air holes with 1 to see if symmetry at the idle jet makes a difference. I'll also try inserting tiny venturi chokes in the jets as well as moving the air holes up and down..... fun fun fun. You should be able to experiment with solder and drilling to your needs then have a final set of new small holed jets such as 40F5's (essential blanks with pilot holes ) drilled to your experimental set's specs. btw did you see my PM? Please email me and I'll send you the Weber Guru's notes.

http://www.classiczcars.com/forums/body-paint-s30/41435-early-hs30-comprehensive-body-resto.html http://www.classiczcars.com/forums/check-out-my-ride/46713-my-1970-240z-hs30-00084-a.html http://www.classiczcars.com/forums/open-s30-z-discussions/51411-hs30-00019-a.html http://www.classiczcars.com/forums/open-s30-z-discussions/1172-hs30-date-manufacture.html http://www.classiczcars.com/forums/open-general-discussions/9485-hs30-family-tree.html

http://www.classiczcars.com/forums/misc-s30/13073-philosophical-discusion-build-dates.html http://www.classiczcars.com/forums/open-general-discussions/7801-production-number-1969-a.html http://www.classiczcars.com/forums/open-s30-z-discussions/26016-jdm-hs30-series-vins.html http://www.classiczcars.com/forums/zcar-history/27315-zg-production-figures.html http://www.classiczcars.com/forums/open-general-discussions/4948-z-production-dates.html

Interesting observations. Sadly today, I spent a few hours fighting with the 510's ignition and did not have time to experiment and collect data as promised.... I only had time to stop fouling plugs with jet change. When I started playing with Webers a couple of years ago, I characterized an idle jet's performance by measuring A/F ratio at idle vs. at cruise (both places are where it works) at different turn-outs of the idle enrichment screw. My goal was ~ 14.0 at idle and 15 at cruise with 12.5 in the high rpm range. [Digression, I ran into problems due to fuel level and the mains clouding the cruise. I hope to have another battle this summer.] Here are typical plots: In the above data I drilled out the air hole on the 55F9 to 1.5mm. I got 14 idle with 13.6 cruise. The 55F11 idle jet shown also gave 14 idle with 13.6 cruise. So I made a "richer" F9 perform like a "leaner" F11 by giving it more air. Here is the same data for the drilled F9 presented slightly differently. Here are the dimensions of Weber Idle Jets in case you wish to drink and drill

Nice win, nice car, nice photos! Congrats!

I think the taper of the needle is the key difference. Can you measure the thread pitch on your 16/17? Here is a bit of of research I did: http://www.classiczcars.com/forums/carburetors-s30/50073-idle-enrichment-screws-flow.html

77 EFI, Tach and 81 distributor all get along well.

It works fine but the chrome rusted. Maybe get black.

stay away from Accel products.