Have 66 impala. Put in 305 from 80 c-10. Put new piston and rings on all cylinders. Reused the heads,crank,cam. Fired it up and then smoke came out. Took out exhause manifold and saw it came from #1. Took head out looked at it and didnt see much of cracks. Turn the head around and put water and let it sit and water didnt leak from it. then turned it around and put water in the intakes. not much leaking. thinking alls well put it back together. Now there is smoke coming from both pipes at start up and even after 10 or 25 min at idle doesnt go away. The oil looks fine. the engine seems to run good. just the smoke. I changed the oil. filled up tranny to level and coolant too. I checked all the plugs and they had oil. Every single plug had oil in the treads. the number 2 had oil seeping out the thread hole. Most of them did have minor oil as well. I'm not sure if its the piston rings not put in right or if its the heads that are worn. Is there a test to determine this???

 

i'd replace the valve stem seals.

 

As maxxman04 said replace valve stem seals, it they heads sat out for any period of time the seals could dry rot, or they may have simply been wore out from the previous engine

 

Ok i got a valve compression tool. I ordered a valve seal set. I used the tool to compress three valves. I decompressed them and I got the keepers out, the washer, the spring holder, the two springs (inner and big one) and then an umbrella type washer looks to be made out of plastic. and that was it. Was there something missing? After i remove the umbrella, black plastic thing, Isn't there supposed to be a rubber underneath it? isnt that rubber hole suppose to fit on the valve itself and the next thing that the stud touches?? I am thinking that the guy who i got this engine off of didnt put in the rubber part, but I am not sure as this is my first time and nothign comes up on the web.

 

That (umbrella) shaped seal should fit over the part of the valve guide (the valve guide is where the valve is sticking out of) that is sticking out of the head other than that there is no other seal.

 

thank you. I installed the umbrella seals all of them exhaust and intake and fitted it over the valve guide. then i added the spring, the holder and the retainer. Then compressed it it with a handle lever type compressor. then i put the O ring type over the groove closest to the valve guide. Then i added the keepers. then i released pressure on the compressed spring. did this for all valves. Just got done. Tommorow i will see if any smoke comes up.

 

smoke is still coming out. valves covers are tight. new valve seals both umbrella and the oring type were put on. Its a constant smoke. coolant is full. could be oil. engine runs fine. i put my nose to it and couldnt detect anything (even after 4 cups of coffee; clear nose). IDK whats it coming from....

 

Ok so i changed all the valve stems guide seals (used both umbrella) and then used the oil ring type that fits over the second groove on the valve below the keepers. I changed them all the exhaust and the intake valve stems. Then i learned that i put way too much RTV silicone on the intake gasket and found a majority of it was leaking from there. So after using a proper gasket sealer and put it all back together with correct torque (I rethreaded the old bolts as well) its leaking out of the number #7 spark plug. I turned the engine on for about 15-20 seconds and turned engine off and checked plug and it was ALOT of oil. I then took out the plug and then smoke was sputtering out of that hole. Not sure if the sealant I used. It was a permatex form-a-gasket-sealant that is white and directions said spread and then apply the gasket when it feels "tacky". after 2 days I put my finger on some of it hanging out (after tightning intake manifold) and it was still kind of mushy. It moved around and didnt seem like it had a tight fit, The ad on the wrapper says that it hardens but it didnt feel hard. I was looking all over for the edlebrook gasketcinch but they didnt have it. I was wondering maybe could this be the problem? I also didnt use the silicone on the threads. but never have i done it before and it never leaked oil before?? Anyone ever have had this problem before?

 

silicone degrades fast when heat and oil are involved (when laying or bathing in it)