[deus79]

Hey all got a early 74 260z
Just finished putting this car back together and saw that some yahoo smeared poxy resin on the screws to adjust your carbs it will not come out and I can turn the screws worth crap so i'm looking for some good carb setups with the least amount of hassle
1-set of early rebuilt su's
2-duel webbers
3-tripple webbers
4-4brl. intake w\t holly 390cfm carb

My manual on my z is missing some pages on the timing and I can't seem to get it just right so I was also wondering if anyone could tell me the degrees it should read on the crank pully and what the idle should be while I am timing it

Also I tore off the factory exhaust and put on a header.I have no leaks at all from the exhaust manifold to the tailpipe, but while I'm driving I smell fumes really bad
I can't seem to figure this one out either!!!????

thanks for your helpful advice

 

[Gearhead]

The fumes are most likely coming from the rear hatch, or the tail lights. Check the rubber for the hatch, if it's worn, that's probably the cause, or else the rubber around the tail lights where they mount on to the car.

You should notice that the fumes get worse when you have just one window down, but seems to be less when both windows are up. The wind rushing by one window down creates a vacuum drawing air out of the cab and if the rubber is worn in the back it sucks that air (fumes) up into the cab.

As for the carbs, probably SUs ot the dual Webers. Tripples will require some set up and jetting which for some is too much to deal with. I'm not familiar with the 4-brl set up so I can't comment on that.

 

[73240z31]

73 and 74 square edge top carbs are not worth the hassle. On this web site look under the parts and accesories page for a four barrel manifold for 100.00. This is more than resonable. After market parts sell for 300.00. If it is the four barrel similiar to the one I own, it will accept any four barrel with holley (almost any carb) bolt pattern. Real common is the holley 390 cfm. This carb is very drivable at resonalble price about 300.00. Weber DGV's used will run new about 600.00 to 900.00 and new 1000.00 to 1200.00 both, triples used (very rare) 500.00 and up depending on the size of the outer venturi 40mm 45mm 50mm 55mm. Mikuni is a very reliable carb but no longer available, however webber is still producing them and are very common aftermarket. The exhaust leak is form the rear of the car, brake lights not sealed or rear hatch. Timing all depends on the mods to the car. I found that for smog, 0-5 degrees. for all out performance it gets real complicated when you factor in timing cerves with spring and weight distibutor mods.

 

[Z-Fan]

Several folks have had success with those flat-top 260Z carbs...check the archives here...and a lot (a LOT) of folks go with the early round-top carbs with great success...and the above post is the first one I have seen that has had success with the 4-barrell...just goes to show that if you got your act together (and that dude HAS) then almost anything is possible...Good Luck )