I think I have a pretty tired Olds 455 on my hands. It's a 1970 Block with 72 GA heads on it. Probably done so some previous owner could use cheaper gas. Just a hunch though. Anyway, here's my symptoms.

-Spark plugs are all fairly new. All are almost black with soot and many have oil on the threads and a few have oil on the porcelain too.
-Engine likes to smoke a little bit out the pipes. Not a thick cloud, but definitely noticeable (smells great!)
-Pretty noticeable smoke cloud emitting from the right valve cover breather
-Plugs are Autolights, heat range 6.
-Engine is NOT running rich.
-Oil was changed by prev owner 3 years ago, engine has sat around and has not been driven since then. So it's good fresh oil. Smells like GAS on the dipstick and under the filler cap.

I know these are tough old motors and I really don't mind if it smokes much. Just as long as it's runs and powers my big old Army truck okay. Not a daily driver anyway! Would just like to know what could be causing the above. I am pretty sure the motor has NEVER been rebuilt, even has the stock timing chain which needs definite replacing ASAP.

I love my old smoky 455.

 

Grab a compression tester, and an oil can. Pull all your sparkplugs out, and disconnect the ignition.
Test all the cylinders with the carb held open for 4-5 cranks, and write down your numbers for each cylinder.

then squirt a few shots of oil in the holes, and retest.

 

As far as the plugs being black:

Could be fuel fouled, oil fouled, or your exhaust could be clogged up, and carbon fouling them.
Do your exhaust manifolds have that stupid damper in them? Those get stuck closed sometimes.

 

Running manifolds only,no downpipes. Yeah it's loud! When I get it on the road i'm taking it down to the custom exhaust shop. That's if I don't torch the entire truck in gas first just to watch the stupid thing burn.

I can do a compression test tomorrow, I have a gauge.

 

A few years ago, I broke a rocker stand on my '69 442 and deceided to replace them all, including the arms, valve seals, and shim the valve springs.
Seals were in little pieces apon removal - real glad I did them!
Vacuum went up 4 lbs. and resolved oil consumption, too!
Have since done valve seals on a few other Olds motors, resolving many probems!

 

Found my problem. Oil drain holes in the heads were nearly clogged shut with oil deposits and varnish buildup. Seals still look pretty good and I'm 90% sure that oil pooling in the covers is the cause of the fouled plugs and light smoke at idle. Which is also another reason it's so gunked up inside. This poor engine has hardly been used for the better part of 20 years. It has sat idle in a junkyard inside a big green army truck that was never made fully road worthy. It just needs to be DRIVEN and USED some now that the truck is almost road worthy thanks to many months of blood, sweat and hard labor.

Which brings me to my next question, can anyone recommend a decent additive that actually works to clean out old gunked up big blocks that have primarily seen mineral oil their whole lives? Don't really want to go full synthetic right away for fear of breaking too much crap loose inside and clogging something up.

 

mr gunfreak were are the oil drain plugs located and how did you clean it.??i am havin the same problem. on my 455

 

Clean as much of the crap out by hand with a shop vac, flush it into the oil pan, drain the pan and refill with a couple quarts of automatic trans fluid. Don't run the engine hard, or on the highway. Trans fluid is a lot thinner than engine oil, and wont handle the heat. It does have a lot of detergents that will clean the gunk out. Be prepared to change the filter and oil a couple times after.

 

And, if your oil smells like gas, the well plugs on the carbs are more-than-likely leaking, and has to come apart to repair.
65 442 had the valve seals fall apart - clogged the drains + hardened oil gunk - had to use a wire coat hangar to clear - certainly not fun on a air car!

 

Well, if it was, he was not successful. The E heads and the GA heads have the same combustion chamber size.

Is this the motor in your truck? Doesn't smoke just add to the ambiance?

I would suggest a leakdown tester instead of a compression tester. You'll get more useful information that way.