yes,they do...
You likely have a valve stem seal problem,or perhaps a few loose intake valve giudes,if it only smokes right after you start it..
Oil has what is called a "flash point"--the temparature that it will ignite and burn at..this varies among different viscosities and brands of oil,and also whether its petroleum base or synthetic...heavy oils like 20W-50 ,SAE 30,
SAE 40,SAE 50 have higher flash points..the higher the flash point,the less smoke you'll see,and less consumption will occour..most synthetics have a much higher flash point than petroleum based oils..(but they also sneak past worn parts better,and can actually be used up faster than conventional oil!.)
I've read that parrafin based oils like Quaker State from wells in PA have a lower flash point than others made from crude pumped from wells further south...
Usually switching to a higher viscosity oil with higher flash points will reduce smoking ,blow by,and excessive oil consumption if the rings are leaking,but if its the valve stem seals or guides causing the smoke,the oil,or "stop smoke" additives dont seem to make much difference,it smokes about the same,because the oil is dripping directly onto the piston and spark plugs,and just about any brand will burn when subjected to the high combustion chamber temparatures there..
My 305 in my 79 C10 puts out a big "PUFF" every time I start it..but it does not "use" oil,it takes 2000+ miles to burn a quart!..I am not going to attempt to change the valve stem seals,I feel its GOOD for a motor to start "well lubed!",as long as it doesn't foul the plugs (and mine doesn't)...I will leave it alone,I have it up for sale,and have no $$ to spend on it anyway..
