my datsun 1200 is blowing smoke, had the valve seals checked and the gasket is new?

What colour is smoke? Blue-ish or white?

If you have black smoke, that means the engine is overfueling.

If you have grey smoke, that means that the engine is burning oil, usually caused by worn valve guides or worn piston rings.

The third, which you don't have since you replaced the head gasket, is white which is when coolant or water gets into the cylinders.

th smoke colour is white

White smoke + new gasket = blown head gasket.

To confirm it is white and not bluish-white, watch the smoke carefully. If it dissapates it is steam (water vapor). It is does not disappear but only dilutes and drifts into the wind that is oil smoke.

Furthermore, do a Compression Test - both wet & dry.

Havent done a comp test on it yet as i dont have a tester.....

But a head specialist has told me the valve guides are fine and has added new positive valve stem seals as a 'just in case' precaution....

In an effort to stop the smoking the Head has been refaced, valve guides checked, new valve stem seals fitted....

Please note, the engine was not smokey prior to me removing the head....cleaning up the valves and piston crowns.....the head was removed because i feared i may have damaged the valves after it had been detonating for about a week.

The head specialist also stated to me that its highly unlikely that all 4 sets of rings would fail all at the same time.............so im at a loss guys, Please help....

PCV valve has been checked and cleaned aswell.

I should also add aswell, ive pulled the head off twice since this problem started in an effort to find and fix whatever is wrong and each time there has been roughly 2 tablespoons worth of oil sitting in each bore on the piston crowns, and im talking pretty much the exact amount on each 1.....

Compression test. Detonation can damage the rings.

Also inspect the PCV system as it separates oil from vapor in the block ventilation system.

Well, looks like the problem fixed itself, after good drive the smoke started to clear up.....and she still had plenty of oil...

Ive looked into it some more on the web and although i cant be sure, i think it may have been the oil rings sticking as some small amounts of coolant may have got into the bores when i first removed the head.....

Thx for all your assistance guys

After you change the head gasket sometimes it will smoke for 10 or 15 minutes from all the oil in the all the wrong places. This eventually burns off and never occurs again.

Good on ya.