i`m not an very good english cpeaker so it will be hard for me to say what i am willing to say...hope you will understand...i don`t know much techical terms...
I have a Datsun Sunny 140Y, B310 ...... a week ago the..hmm.."spindle".. "tip cart" ....the axis at the top of the engine....the axis that holds the "things" that controls the admision and the evacuation...hope you andertand..has broken...i cannot fin another one so i ask you if there is another one compatible with this..from other car....it cannot be weld or so i was told.....
Without it the oil leaks on the...hmm..on the thing with the plugs :)
Hope you`l understand. Thx.

I think that you are saying that the "shaft" that the rocker arms move on is broken.
This shaft is under the metal cover at the top of the engine & lies along the line of the engine. That is to say, front to rear.
Is that correct?

These rocker arms push the valves down to allow the gasses into,... & out of,... the cylinders.

If this shaft is broken, it will be necessary to find the reason why. Lets go one step at a time & make sure that we know what it is that is actually broken.

Yes that`s it ! the reason might be something that i did..at app. 90 km/h the acceleration pedal remained blocked and my foult was to press the clutch pedal..and the engine reached...don`t know..many rpm.
After that the car wouldn`t go.....

And something else...the "shaft" had 5 screws...the las one was broken...probably the screw broked firs and the the shaft remaines in 4 scres and broked too
Excuse my english :) in mine language i speak very good :))

Wow! You will probably find that the push rods that come up vertically from the inside of the motor will be bent as well. You will need a new rocker assembly and new pushrods from a 120Y or another 310. You also need to find out whythe accelerator pedal jammed open. I wonder what the revs went to before it broke?

It jammed open couse the cable was broken and he remained stucked into the covering..hmm..we call it "shirt" :)

You speak & write in English much better than i can speak any other language at all, so do not appologise to me. It is not necessary.

If the shaft is broken, you will need to look at the bolt that was holding down the "pedestal" at the back of the engine. Is it broken, or was it just pulled straight out of the head?

If broken, then you will need to get the broken part out & you need another bolt.

If it pulled out of the hole, then it has ripped the thread out as well & this will need to be fixed.

It sounds like it will be better to get a whole rocker assembly from another engine. Fortunately, they are able to be used from almost any of these "A" series engines. It would be best to replace all of the push rods too, but you must get these from an engine that is the same as yours [A14?] as the diferent engines used diferent length pushrods.

Are there any places that sell used car parts [wrecking yards, or sometimes called breakers yards] in your part of the world?