rebuilt engine smoking !

[bigvette1]

Oil Smoking

Do you still have your PCV system still hooked up along with the passenger side breather tube? If so, pull the PCV off and check that rubber tube that goes from the PCV to the carb. Let us know if it is soaked in oil inside the tube. When I did my rebuild I had oil blowing past the PCV and into the intake manifold via this rubber tube. I installed an oil catch can to resolve the issue of oil being sucked in to the intake and mixing with the air fuel mixture for burn.

I am reading this post and damn if it is not a direct quote of the problems I have on a BB after a rebuilt. Difference is, the heads were redone with new everything including cut for and installed PC seals. Supposed to be great.

The smoking is predominant after totally warm - metal expands. One garage said since the bottom end was bored etc they would think the cylinder walls are not a perfect bore top to bottom and when warm, oil sucks up the walls. I have tried 3 differnet intakes and 3 different carbs with no affect. My PCV lines are not wet with oil and the valve covers have baffles in them.

I with stupid luck may have stumbled onto something this week. The timing was real hard to set and the engine bucked when warm and then fired. I pulled the distributor, found tdc and put it back in like the book shows on a BB - rotor pointing to #1 tower but having #1 aligned near the vacuum can, which was 1 tower clockwise. This also with a MSD distributor put the mag pickup dead center in the pickup coil. Changed the wires around and presto the timing was easy to set and did not show signs of being super advanced. Talked to an "expert" and he said you most likely had a problem of pulling fuel from the boosters and actually pulling oil from the cylinder walls because of the super advanced timing - called it a reversion process. Anyway after an hour of running the amount of smoking was reduced to almost nothing. I probably have a ton of oil and gas on the valves, in the pipes and in the mufflers. Just maybe......

Sorry it was so long, just sharing an experience that might be something to look for. Still think the bore job was suspect.

 

[Zeke68]

smoking engine

Dont know if this could be the issue or not but I work for caterpillar large engine division and we were testing a new engine and it ran great till warm and the oil pressure started dropping. To make a long story short assembly had installed the rings upside down. We blew 125 gallons of oil out the exhaust. Yes 125 gallons in a matter of minutes, thease aer big engines. I couldn't remember there is a up or down side to car engines but someone out there probably knows.

 

[Rodney Gold]

The lack of valve stem seals is almost a guarantee you gonna get oil going into the engine...apart from that , it could be that the bores and rings havent broken in properly and the bores are now glazed....
Check to see that you have the breathers working correctly , one side of the engine needs to go via a pcv valve to vacuum and the other side needs to be vented ..

 

[92BlackVette]

My 76 vette smoked after new heads/intake, the headers were loose.

 

[madmoon]

thanks to all !!!!

just a quick note to say thank you all very much for your helpfull answers and consideration of my vette problem. i have now fitted new valve guide seals and used some much better inlet gasket sealer. she now runs lovely and not a whiff of smoke !! she has just passed her annuall ministry of transport check that we have here in the uk and is ready to rock n roll chaps. thanks again to you all and please just send us some nice usa sunshine so we can go topless, lol. phil and gina from uk.