Smoking Issue

[6061Apache]

I have a 61 Apache with a stock 283 and a manual trans. It smokes out the exhaust when I coast down a hill, and pushes a little oil out the oil fill tube at the front of the intake manifold. Doesn't smoke at startup, or going down the road, except downhill. The only crankcase vent is the oil fill tube. Would it help my smoking issue if I added breathers to the valve covers, or is my motor just shot? Thanks for any comments.

[Tim Cline]

You may have to pull the valve covers and clean out the oil return drain holes. I have seen those stopped up a bunch of times causing smoking at different times. It also could be worn valve seals/guides. Also that engine should have a vent at the rear of the engine block that connects to the carb with PVC valve or (not sure what years) had road draft tube that vents downward. I know for sure 63 to 67 283/327 had the PCV set up.I hope this helps. If the rear vent is connected and working then you wont need vents in the valve covers.

[Straydog]

I f your valve guides are getting worn and old trick I used was to install Ford small block umbrella valve guide seals instead of the o rings that gm uses.You can do this with the head still installed,by using a fitting that screws into the spark plug hole like a compression guage line. hook your hose from your compressor up to it and pressurize the cylinder. this will hold the valves in place while you remove the valve springs and replace the seals.
ONE CYLINDER AT A TIME.

Plugged drain holes as Tim Cline said along with loose guides and or bad valve guide seals will cause intermittent smoking.

Oh! make sure both valves are up (closed) before you pressurize the cylinder...

[maxwoof]

Coasting down hill, foot off the gas, carb throttle plates closed would create a high vacuum situation in the intake. That could very well suck oil past the valves if the guides/seals are leaking.

[6061Apache]

Thanks for the input, looks like I have a few things to check.

[Old Truck Man]

could be valve guides and could also be rings. since you state their isn't any smoke on startup that indicates its not valve guides or seals. deceleration going down a long steep grade will create exceptionally high manifold vacuum. that can suck oil past the piston rings & valve guides even if their not worn that much.. If you have excessive puff back (blow by out the oil fill) its a sign that some compression is leaking past the rings. I would suggest pull the valve covers and make shure nothing is plugged. install a PCV system . A PCV don't hurt HP or fuel economy. What is does is revieve crankcase pressure a bit. it removes moisture and combustion gases from the crankcase. it will help keep the engine cleaner. Unless the engine is using excessive oil & fouling plugs I wouldn't worry about smoke after a long deceleration. A PCV system and electronic ignition are two upgrades I will always recommend.

[AcampoDave]

I bought a truck with a 283 that ran o.k. but smoked. Turned out to be the intake manifold gaskets. Somebody had put a 2bbl set up on it, (but one of those big ones like a 400 had), and did a poor job, gaskets were soaked in oil. Probably not your problem but thought I'd mention it just in case it strikes a chord.

[Tim Cline]

To add to what straydog said, another way to change valve seals with a piece of rope. I know this sounds weird but I have done this and it works. Here is the way I did it to keep the valves from falling down when keepers are removed. Remove spark plug, rotate engine until cylinder is at TDC (both valves closed),(watch rocker arms) and then Timing mark to confirm TDC. Rotate engine (lower piston) until you can see top of piston thru the spark plug hole. Now here is the trick -you need about 6-8 feet of tightly wound rope maybe 5/16"(just smaller than the spark plug hole). Push all the rope you can fit into the cylinder (fill the cylinder), (leaving enough to pull back out), rotate piston back up as far as you can to compress the rope against the valves. Do this by hand not with the starter. Now your valves will stay in place because the combustion chamber is full of rope and there is no room for them to fall into the cylinder. Remove keepers and replace valve seals and keepers. Rotate piston down until rope is loose and can be removed. This has one more added benifit that when you pull out the rope most of the carbon on top of the piston will come out with the rope. I hope this trick will be useful.

[Tim Cline]

On the Rope trick make sure you use stiff woven rope that is not spongy but firm. This make sure the rope does not compress when the valve spring is compressed to install the keepers.