If the a/f mixture is correct, but the plugs get carboned, then either the gap is incorrect or hotter plugs are called for.

I doubt that incorrect mixtures could lead that badly to over heating, unless the carby was blocked to some extent. But as the lads have already stated, flush the radiator.

A stock A14 would not require a radiator upgrade, just get a proper rad place to flush it properly. You'd be suprised how much a difference it can make. Get the cap tested, when they don't hold pressure the engine runs hotter. And a sticking or partially opening thermostat leads to poor water flow. An easy test is to check with the palm of your hand from the front of the radiator with the grille removed the surface temprature of the radiator from top to bottom and everywhere inbetween to check for cold spots in the core. That can help you to locate a blockage.

Another thing is oil. In the hotter weather a thicker oil is reccommended especially in older engines. And if the iol is past it's use by date it can also cause running hot problems. Being a pushrod engine you can get away with something heavier than 20/50 oil. If you don't rev the piss out of it, the engine won't come to any harm.

I did have some hoter plug,s in it up untill a few months ago it still foured them just took a bit longer. Think i will have to rebuild the A12 i Finshed pulling apaet the block today it looks like it would be a cheap rebuild hope fully?

Rebuild the engine because of fouled plugs? That's crazy. An engine needs rebuilding when the rings are shot, or the bearings are shot. Fouled plugs means you need to find out why.

Do a compression test to reveal if it really needs rebuilding or not. And if it the compression is low, but it does not have any bearing knock, it probably only needs new rings. Don't fix what isn't broken.

What about the amout of smoke it blow,s
And it,s my A12 iam rebuilding not my A14 that iam talking about in this post

Depends on what kind it is. Black smoke coming out the tailpipe -- even if there is a lot -- is not fixed by rebuilding the engine.

Bule smoke
I want to rebuild one before the cops tell me to take it of
the road

Hi Dave, yes, if it is emitting bluish-white smoke and the compression is low, then it probably needs new rings. There are some other less common causes of bluish-white smoke, so a compression test is called for to confirm it.

To replace the rings, you need a "head set" gasket kit, new rings (I got mine from Repco), feeler gauges, and an oil pan gasket. If the cylinders have do discernable ridge, you don't even need a ridge reamer. The A-series is a good engine and usually rings is all that is needed. The feeler gauge is to measure the ring end-gap in the cylinder and side-gap in the piston. Be sure to follow the procedure in your repair manual (Gregory's, Haynes, Datsun Factory Service Manual, etc). Datsun does not call for honing or glaze-breaking, so keep it simple unless the cylinders are worn. If there is a discernable ridge near the top that you can feel with your fingernail, then it gets more complicated, and the bore dimensions should be checked with micrometers and boring may be required.

While you have the oil pan off, check the bearings with plastigage ($5). Chances are they will measure out fine if you don't hear any knocking now while it is running.

Yes your right it is Bluish-White smoke.
I have Three A12 Block,s the one i removed from the car before the putting in A14 i
only did so Because The valve stem seals shot and it only had a problem in nmb4 piston.
I was pulling out the plugs every two week,s to clean. And only the 4th one was oily the rest whear ok just dirt brown maby carbin. I did try the hoter plugs on this engine dident do alot.It allso had a valve that had hole in on nmb four. But we fixed it before i put rego on the car. Anyway i think i would like to rebuild A A12 just because of petroll price,s and the A14 is allready in the car maby i should rebuild the A14 because i think the head is probley in better condition.
All so the A14 does seam to use any more fuel any way
Yes i do have a manual its a Gregorys 120y

Do you want to fix it so it won't smoke anymore?

Or do you want to rebuild it, even if it doesn't need rebuilding?

Your choice.