"iDatto does'nt know me or what i do etc. but some people will always learn the hard way,i tried to extend an olive branch once before only to be shut down.....such is life."

I'd like to drop in to your domain one day bert to have a look at everything and hear what you have to say about the A-series. Wouldn't mind a chat with vixxen too.

are those su's the same as the gx, or similar?

gx or hitachis are called SU's because they are are direct copy of british SU's but probably better like most jap copies of anything

SUs are different. Made by Skinner's Union (S.U.) Fittings, linkage, and parts are all different. The general layout, bore size and mounting bolt pattern are exactly the same, except SUs generally have 4-bolts and most Datsun manifolds are 2-bolt. A four-bolt manifold with fit both brands of carby.

Aftermarket 4-bolt SU manifold for A12 engine:


Lynx D1000

Datsun Factory Twin-Hitachi Manifolds

Minor point of order here.

The manifold in the picture is one of mine & is a Lynx D1000, made specifically for the A10 engine in the Datsun B10/1000 range.
It will fit & work on the 1200 & later small port A12 engines but has no provision for a PCV valve which the A12's need but which the A10 didn't use.

Lynx also made another version of this manifold that DID have PCV valve provision & this would be the one to get.

Some SU carb. models came with the two bolt mounting from memory & they would fit this manifold without difficulty.

When it comes to a mild street A12 engine, I must confess that I fell in love with the GX induction system just after I installed a 1200 GX engine in my B10 sedan almost 30 years ago. I used it for something like 15 years & I still have the induction system & head, but not the rest of the big bore engine.

The engine started easily, ran smoothly, pulled well, went fast enough to seriously frighten me more than once & when driven for economy, it returned better than 52mpg [Imperial gallon or 4.54609 Lt]

I loved the GX induction system then, & sing it's praises still.
A properly set up aftermarket SU system should perform almost as well, remembering that the GX manifold is water heated which is a big advantage on a cold winters morning in traffic.

If you normally drive your car/Ute at engine speeds above 5,000 rpm then Webbers would have a clear advantage but for regular street driving & cruising it would be the GX or aftermarket SU system for me.

yeah i try to keep the revs up
but but but, there is more traffic lights on the road than on a track haha
so that means alot more stop start

well
im going to motacarb on monday and mal and craig are gunna have a litle look over her and give there two bobs worth

I'm with Dodgeman,
having run GX's on the street, very forgiving and great performance, the "SU" type carby runs on the supply and demand theory, if the engine sucks harder they supply more.. all good,
I also love the Sideys, Solex/Mikuni, Dellorto's and Webers, properly setup and in good condition, trouble fee motoring,

im thinking of runing just a single down draught on this engine
and building up an a15 with all the good bits on it over a couple of years or so, just gathering the parts slowly whilst saving abit of money to put towards at house
and possibly find a sedan and put the engine in it and get it running then when the time comes swap the two engines over into eachother, or
get the sedan set for abit of track work
are 4 door sedans, rare/expencive/shit?

4 dore sedans are far rarer than utes, but more commen then the rest. and odly useualy cheeper then utes witch I dont understand??