Sbc 350 fresh rebuild problems

[docrocket1967]

So i sold the 78' El Camino 454 as some of you know and i bought a 86' Monte Carlo SS. Then engine was supposedly rebuilt not too long ago. He did give me receipts to prove it. What i would like to know is what you think my issue might be.

When driving the car and only when it warms up does it smoke but it does not smoke out of the tailpipes it smokes from under the hood and out the back. The harder you are the worse it gets. I do have oil coming out of my breather capi noticed and also at one poin out of the intake which i did replace the gasket. The engine does over heat and it doesnt take long but only when it sits still. When im driving down the road it will not ever overheat. Do you think maybe the rings are garbage or do you think this could be an issue with the pcv valve and some vaccuum hoses causing this? If so do you think this is the cause of my overheating? The engine has a pretty crappy flex fan on it and an electric fan behind the grille that is not functioning due to the wiring that was previously screwed up. Your help is much appreciated. Thank you.

 

[jmt455]

Yes, the smoke could be due to a plugged or incorrectly plumbed pcv valve...make sure the valve is working properly and that the vacuum lines are properly connected.

Are you sure it's overheating? Did you confirm temperature with a known good gauge or infrared thermometer?

Overheating could be caused by a number of things...
First, look for a missing, malfunctioning or incorrect thermostat. I've even seen them installed upside down.
I would definitely get rid of the flex fan and put a GOOD clutch fan on it. The edges of the fan blades should be 2/3 (or more) into the shroud and no more than 1/3 "behind" the rear-most edge of the shroud. When you look for a fan, keep in mind that the fan diameter should have about 1/2 inch gap to the opening on the fan shroud. (for example, use an 18 1/2" or 19" diameter fan in a 20" opening)
Building too much heat could also be due to incorrect timing (not advancing properly), but if it doesn't overheat when driving, I'd go after the fan/shroud/thermostat.
I would get rid of that electric fan until you figure this out. If that fan's not actually running, it's just obstructing air flow through the rad.

I don't want to sound negative, but maybe those receipts were not for this engine...

 

[CHRIS.O]

If you pop the breather out or pcv out is there a lot of blow by?

 

[docrocket1967]

Yes, the smoke could be due to a plugged or incorrectly plumbed pcv valve...make sure the valve is working properly and that the vacuum lines are properly connected.

Are you sure it's overheating? Did you confirm temperature with a known good gauge or infrared thermometer?

Overheating could be caused by a number of things...
First, look for a missing, malfunctioning or incorrect thermostat. I've even seen them installed upside down.
I would definitely get rid of the flex fan and put a GOOD clutch fan on it. The edges of the fan blades should be 2/3 (or more) into the shroud and no more than 1/3 "behind" the rear-most edge of the shroud. When you look for a fan, keep in mind that the fan diameter should have about 1/2 inch gap to the opening on the fan shroud. (for example, use an 18 1/2" or 19" diameter fan in a 20" opening)
Building too much heat could also be due to incorrect timing (not advancing properly), but if it doesn't overheat when driving, I'd go after the fan/shroud/thermostat.
I would get rid of that electric fan until you figure this out. If that fan's not actually running, it's just obstructing air flow through the rad.

I don't want to sound negative, but maybe those receipts were not for this engine...

I have not confirmed it overheating with another gauge only because this gauge is brand new but it wouldnt hurt. Def agree on getting rid of the flex fan. That is true too about the receipts but everything the guy has said so far did add up so i am leaning on believing him.

 

[docrocket1967]

If you pop the breather out or pcv out is there a lot of blow by?

No there is no blow by at idle only at higher rpm's. I did discover i have a very bad valve cover gasket leak after driving this past weekend. Do you think it may have something to do with the high volume oil pump producing too much oil up top at high rpms?

 

[84dragcutlass]

Probably just the oil draining down and landing on the exhaust causing the smoke, high pressure oil pum can cause leaks if the valve covers are warped or the gaskets are cheap or just not put on right

 

[CHRIS.O]

No there is no blow by at idle only at higher rpm's. I did discover i have a very bad valve cover gasket leak after driving this past weekend. Do you think it may have something to do with the high volume oil pump producing too much oil up top at high rpms?

Get any oil leaks fixed first and clean off all the leaking oil. If you had blow by from worn rings or cylinders it would be easy to see when you took the breather out. It would puff smoke out of the breather hole.

 

[docrocket1967]

Cool. Got alot of peace of mind from this and thank you for the help

 

[docrocket1967]

Alrigi found what i thought was the leak and it did stop alot of it. The passenger side valve cover gasket was pretty much no good so i replaced it with a pretty thick fel pro gasket and some good silicone now its blowin it out of the front part of the valve cover same side and the breather. But i didnt think the motor was very high performance but i stopped today and got gas i always ran 89 octane in it before but today i had no choice but to put 87 and i got up the road about 4miles and it started running real rough. Any more ideas guys? I appreciate the help

 

[Bowiemontecarlo86]

MAYBE your valve cover is warped like was said. Also change your pcv valve its cheap.