Possibly sticking valves?????

[klaussk]

So I have been having a problem with my truck its a 85 k10 with a 305. It has a new Holley carb and the ignition system is all new. Its idling rough and sometimes bogs down really bad. It sounds like the timing is bad when I rev it up and it back fires through the carb. I have to time it by ear because theres no timing tab or mark on the dampener. But no matter how much i adjust the timing ( while still keeping it idling as smooth as possible) the problem doesn't change. It also blows white smoke when I rev it up. I checked for a blown head gasket and saw no signs of it. There is white smoke coming through my breather valve on the valve cover and through the hole for the PVC valve on the other side if I remove the valve. I have looked into the oil fill hole while the motor is running with a flashlight and there doesn't seem to be allot of oil in there at all. I don't see any squirting anywhere or any oil movement at all. I think I might have a clogged oil journal or maybe a bad oil pump. anyone have any suggestions. Also my oil pressure is around 28 psi.

[1980c10]

Check your oil level and see if it has risen or if you have coolant mixed in and vice versa. I would remove the valve cover and inspect the top of the head. If you don't have your answer at that point; do a coolant presssure check/leak down test.

[HAULIN IT]

Well it sounds like you have a verity of things going on there. For starters, Anytime you have White smoke (really any color) you need to be concerned & find out what is causing it. White smoke typically means water (could be trans fluid though), start with that since it could be the worst problem/lead to other problems.
How did you "check for a blown head gasket"? Is/does the coolant level go down? When you say "blows White smoke" are you talking out the exhaust or this breather activity, both?
The 28 psi is normal for stock SBC's of that era, no concern there if you have adequate flow...If the rockers aren't rattling like a can of marbles, I wouldn't sweat the "oil thing" yet.
Are you sure the smoke coming out of the valve covers is White & not Bluish? Oil out the valve covers would be far more logical/common.
The mentioned coolant system pressure check/cylinder leakdown or compression test will likely lead you in the right direction.
As far as the timing goes...look the balancer over better, there has to be a line on it somewhere.
You will need to verify TDC on #1 & get the correct pointer (there are a couple different ones) .
The bog & backfire sounds like a yet another problem or Two. I wouldn't associate "bog" with timing, however the roughness could be. Report back & we'll try to help! Lorne

[1979C20]

The best way to find the balancer mark is from under the truck, because you can see the hole.balancer. And, check your spark plugs. See how theyre burning. If its backfiring and bogging maybe your fuel mixture is off.

[Blazin]

My experiance with backfire through the carb is a worn /  bad cam.

[klaussk]

Sorry I haven't responded to this thread recently guys. We had a serious fire on my ship and lost power to some stuff for a few days so I haven't had access to the site. I cant find any coolant mixed in with the oil. The  smoke might be slightly bluish Ill have to take a real close look at it today. Most of the time I get to work on it is dusk or later cause we get off work at like 8 every night, so its hard to tell. will it be more like a blueish tinted white smoke? The rockers seem to be rattling alot more than they used to. Actually when I got the truck the engine sounded very smooth. It blows smoke through the exhaust when I rev the engine or when it dies down once and awhile. It is always coming out the breather though.Ill look the balancer over better today from underneath the truck. What exactly does a leakdown test do and how do you perform one. I have down a compression test before. I just need the Gage and everything. I think I should get a vacuum Gage also.

[Grim 82]

White smoke= coolant
Blue smoke= oil
Black smoke= fuel

This is a pretty cool explanation of the leak down test:
http://vmaxoutlaw.com/tech/leakdown_tester.htm

Check all the fluids as mentioned and pull the plugs and see if you can narrow your search down to a particular cylinder. A worn intake valve guide or a missing umbrella seal or o-ring that lets oil pour down the intake valve and foul out the plug will smoke like crazy too.

[klaussk]

I pulled all the spark plugs and they all look almost identical. My friend says it smells like its running very rich but its  a whitish blue smoke. Its hard to tell I can never get out there in the daylight to check. I still gotta look harder for the mark of the balancer. I have decided that If it is a head issue I'm just gonna buy a crate 350. This 305 has seen better days and I don't want to put any more money into that engine.