Engine noise piston

Have a shop take a listen, the 5.3 V8 has a common noise called piston slap. The piston slap doesn't affect the life span of the engine, a trained ear will know the difference in the noise.

I think my friend, you should look towards getting your engine replaced. If you hear like a clicking or clunk noise while you drive, the internals of your engine are worn out and hitting against each other.
Your options are:
1. Scrap car or sell it
2. Swap engine for a new one
3. Get the engine reconditioned

There are of course many possibilities as to what the noise could be. It is troubling that a mechanic listening to it could not make a better diagnoses other than piston slap. Early Suzuki four strokes often had some piston slap probably due to larger tolerances. This sound generally will go away or lesson as the pistons get warm and expand. With out being able to hear the noise , my best guess is pre-ignition. Start by doing a compression check, both cylinders should be over 110 PSI and with in PSI of each other. If compression checks out, install new spark plugs and more importantly new NGK spark plug caps (about $5 each). Next take off the carburetors, inspect the intake manifolds for cracks or separation (air leaks), clean remove the carburetor tops and inspect the vacuum diaphragms if damaged or pin holed replace them (about $152 each)(a used set may give you the needed parts for less), thoroughly clean and reinstall the carburetors. If the problem was just a lean condition on one cylinder this may bring the cycle back to its original glory. If the damage is deeper in the motor (crank) perhaps a donor cycle or engine would be the best option. Unfortunately, the only way most of these options will work is if you are willing to put in the sweat equity your self to save the labor rate.

The upper windy noise, I would keep an eye on but the tapping noise sounds more seriouse.
I would purchase some Slick50 to add to the oils. They do a special grade for particular bike engines and it will ensure you minimise the wear.
I take it this noise has happened recently or has it been getting worse over a few thousand miles or so?
If it has just happened it may be piston slap if it it there at all times or if loudest on the over run little end bearings.
When you are able, check the compression and take the top off to examine the pistons, (broken rings) and bearings.
Hope that helps a bit

It may be piston slap. This is caused by either engine wear with the piston bores being too large for the pistons, or by poor manufacturing tolerances, or a combination of both.

To test for this, start the engine up first thing in the morning and run it for about thirty seconds while you listen carefully and memorise the sound and intensity. Turn the engine off quickly, remove the spark plugs and put two squirts of motor oil into each cylinder. Reinstall the plugs, start the engine up again and listen. If you have piston slap the noise will have been greatly reduced or even eliminated for about thirty seconds seconds and then returns.

The fix is to rebuild or replace the engine, but if it works just fine then don't worry. Many slappy engines keep going for tens of thousands more mile. The fact that your knocking is only at idle suggests your crankshaft is not to blame.

a common cause is carbon on the top of the piston or on the skirt, this makes the piston tilt from side to side under power and causes noise, the other is a worn piston or a cylinder that is not honed to the right size and piston can move excess, another is a cracked piston

The smoke if it's white and goes away is just condensation in the exhaust system evaporating and the clicking noise could be the famous GM Piston slap. You can take it to the GM Dealer, there is an upgrade ECM program to help eliminate the piston slap noise when the engine is cold. You can also try adding some Lucas engine treatment to your engine oil to help with the piston slap problem. Start with that and hope it's not overdue for an oil change or low oil level in the engine.
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Not sure what you mean from a faint knocking. Faint Knocking noise refers to piston slap till the engine warms up and a Tapping noise refers to a noisy lifter, if it's a bad lifter. The noise would get louder as the engine's RPM rises. Most GM owners have the problem of Piston slap first thing in the morning when the engine is cold, it's common and was made that way. The tolerance clearance between the pistons and cylinder walls are quite large since the majority of people do not warm up there car, so as you get on the gas and the pistons expand to the right size and will not wear out the cylinder walls giving the engine a longer life. The side effect to this is piston slap till the piston expands, that's why they say that you just have to warm up the engine for 2 min and then drive. Personal I'm not one to get in and drive, I'll always warm up the engine enough to see the temperature gauge go up. My wife has a Montana with over 150.000 miles and no piston slap after the first oil changed. I found that adding some Lucas engine oil treatment and a can of Engine Restor every second oil change has kept the engine running smooth and quiet, And about 500 miles before the next oil change. I add a bottle of Marvel Mystery Oil, the Mystery oil is thinner and will clean out the internal oil journals to the crank shaft and lifters which would cause the noisy lifter if the oil passage ways are sludge up. The Mystery oil will also clean the Oil Pump Pick Up Screen, ensuring there is not oil restriction in your engine. I have a GMC jimmy with over 350.000 miles and engine still running 100% with this method of service. Good luck and if your due for an oil change soon, add the Marvel Oil and a few days later change the oil and filter and add a can of Engine Restor and some Lucas oil treatment. This should quiet down your engine and add a few more years to it's life. Keep me posted, be glad to answer any more questions you may have.

it may need a lifter or valve adjustment when cold they will tick or knock depending on how loose or worn out then when it warms up they swell with heast and noise stops. after adjusting or replacing it will stop making noise

getting good lubrication flow to the top end of the engine ? maybe some lubrication flow is being blocked to the top of the engine and you hear valve system noise.