I have a 82 trans am with a 305 with a edelbrock intake and valve covers when it runs it smokes considerably out of the back vent
Time to rebuild the engine. Your piston rings, main bearings, connecting rod bearings, camshaft bearings, and valve guides in the cylinder heads, are worn out. Possibly the shafts are worn on the valves, and the piston skirts also. (Means new valves, and pistons, plus boring and honing the block. You'll need a new oil pump, gaskets, freeze plugs, spark plugs, oil and filter, for a few more things to add to the list)
What you are seeing is called 'Blowby'. This is a normal thing with a worn out engine.
Also replace the PCV valve as it is probably clogged up. (Positive Crankcase Ventilation Valve)
500 miles ago?
Sounds like a combustion piston ring, or more, was put in upside down, and maybe the valve guides in the heads were never replaced. (Knurling is a bandaid fix), or valve guide seals weren't used.
Could be a number of things that weren't done correctly, or weren't installed correctly.
1.Honing: Didn't get a good 60 degree crosshatch pattern
2.Ring ridge wasn't removed all the way, and the top combustion ring has broken from hitting what's left of the ridge.
3.Wasn't enough ring gap allowed, and now you have one or more broken piston rings. (Rule of thumb, is 4 thousandths of end gap for every inch of bore diameter)
4.Piston rings weren't set on the piston correctly. Could have been stretched too far when installing, or twisted, if a piston ring installer tool wasn't used.
The above alone, will let hot exhaust gases pass by the piston rings, and build up an excessive amount of blow-by in the crankcase.
Do you have the PCV valve in one of your valve covers, and the tube from it going to the base of the carburetor? Take the PCV valve out. Shake it. Does it rattle indicating the valve is free inside?
By the way. What 'Back Vent' are you referring to? One of those round breather vents that look like a mushroom with a stem on it? (Bad example: This is what I'm referring to ->
http://www.jalopyjournal.com/forum/showt...
Scroll down the page to the first picture in the middle. Shows aluminum valve covers with the breather vent I'm talking about)
Also are you running custom valve covers? Like the aluminum M/T style? Is there a baffle in the valve cover, under the hole where the PCV valve plugs in? I have seen many aluminum custom valve covers where no baffle is present. This means oil splashes up from the rocker arms under that hole, and goes right into the vacuum port under the carburetor.
×
Back vent on valve cover? some is normal especially when hot. you must take into consideration, all engines have blow by(fuel-oil vapor) that if your not re-directing into the intake to be reburned, will be exspelled through the vents. if oil is this or old or if is running hot, that this will cause this also
417 views
Usually answered in minutes!
the motor was just gone through 500 or less miles ago. And new rings where put in. The valve covers are manual adjustment, i read that this can also cause excess blowby
×