Carb set-ups

[Bruce Palmer]

... 1. There is nothing simpler than a set of SU's. Those that are constantly tinkering would be better off stuffing their hands in their pockets. There is a right way to do it and everybody else's way.

2. Many of the running conditions described here can be contributed to timeing issues, chain stretch, valve adjustment etc. etc. etc.

If anyone wants to de-bug their Z of these issues, I highly recommend our ZTV-01 Tune Up video and the ZTV-09

JUST SU's video. Scott did a great job on these for content and for the price, they are dirt cheap.

IMHO you can't beat an "ON" set of SU's for daily driving. If they are not "ON", they can be less than satisfying.

Cheers.

[symon]

I have no first hand experience on SU carbs on a Z car but on my MG TD with MGB 2150c full race engine, the 2 x HS6s gave 172 hp at flywheel at 7,800 revs & with twin weber I only get 181 hp. Previously I had a Triumph Stag with a Rover / Buick 3,900. With 2 x HIF6s the gave 234 hp at 6,250 revs So they are not bad, just a case of setting the car up properly as suggested by other members & then running down to you local rolling road dynometer & fine turning. The results can be extraordinary !

[frank13]

Like suggested first, the best set up for the 73 L24 is the early SU's. 70-72, lose the smog stuff(airpump, decel valve, egr, all the stuff that can be ripped of the intake and plugged or blocked. Make sure what ever early year you can find complete to get all the parts for the throtle links. Besides the carbs which should be able to out run or stay ahead of a Mazda rotary 13B RX7 first Gen. when set up right by someone who knows Datsun and SU's. Have you tuned it up? Are your feed and return fuel lines at the tank in good condition. It also sound like your head gasket is going south. It happens, I have had two of my Z's blow head gaskets and still run. One still ran on the freeway (not much past 70 mph). Good luck. Is any one going to answer how to open the hood?:devious:

[dogma420]

What makes you blame the SUs normally is some other tuning item that goes out of tune and then the fuel/air mixture gets messed up. The path of fuel from jet to valve is almost straight for a SU, whereas it has to go down and then up and in with webbers (2).

I got the su videos, great stuff. SUs really only have to be tuned and balanced once per tuneup.

If you are tinkering them anymore, then they are leaking at the throttle shaft/worn out or something else is out of tune.

You won't be able to sync them if anything else is off too much.

[zztom]

My rear carb was leaking around the throttle shaft. I could never get them to run great. They were ok for a couple of years but lately they stunk. But now I solved all that. Thakn you, Z-Therapy.