[zan500]

Hey there from Oz,

I recently acquired a set of two inch SU's and am looking at running them on my L28 in my daily driver. They came off a Jag inline six and are jetted and needled wrong for a Z motor.

Can anyone give me any advice on what needles and jets I should be running? I'm pretty sure I need 100 jets (currently has 125).

What are the spacer plates between the carb and the mainfold made from? Where would I get some to suit these carbs?

As always. thanks for the advice.

Alex

 

[FlameZZZ]

You should run them 1st to see if your motor will like the x-tra fuel,if not take small steps down untill your happy.

 

[johnh240]

You can run the 125 nozzles and 125 needles or 100 nozzles and 100 needles. Just can't intermix. Do a search for 'Haystack' program to help you sort needles for sizes you want. I seem to remember that there was a 'conversion' routine in the program also. If you can't find the program, email me and I will send you a zipped copy. Also get a hold of the Haynes SU manual for Weber, Stromberg, SU. It has complete listing of SU needles in the appendix. Might want to look at the applications listings in the same book for close size engines with those carbs. You are probably going to have to fiddle with the springs too, to get the pistons to function the way the engine wants. I've posted some books that are good for tuning SU's (in the last 30 days). You might pick those books up for reference.

 

[Dan Baldwin]

Try the carbs as-is before you go changing things. I found I could run the 2"ers with the needles that were in them. Did the tuning outlined in an old ZCar Mag. Car runs great on the street and at the track. Looking forward to getting them dialed in at the dyno. A dyno run earlier this year was somewhat wasted due to busted spark plug, causing power to stumble above 5000 rpm. Made 177 rwhp at 5400 anyway. I'm using 260Z phenolic spacers, as they're much thinner than the 240Z spacers, giving a little more room for air horns and filters. I hogged out the spacers and the N36 manifolds to match the carbs.

Have fun!

Dan Baldwin
'71 240Z 3.1
COMSCC #7 SPB

 

[Al 260Z]

The horse's mouth on SUs....

is

http://www.burlen.co.uk/parts.html

who took over all SU production and support in UK.

The quoted me their complete set of manuals at about 15 British pounds. Keep meaning to get the order together. How to pay in British pounds? Maybe figure out the right time to call GB and do card over phone.

Later,
Al