[blacknail]

someone hacked out the smog pump, PCV still plumbed into carb. Oil filler cap is ventilated through a series of holes around underside of chrome top. After I run it hard, it smokes enough that people try to get my attention, it rolls from under the hood when I'm at a stop light. Can I replace the oil filler cap with a non ventilated one? What can I do to reduce the smoke?

Thank you!

 

[Joes72/65]

If your PCV system is working (good valve, good vacuum from carb), there is something seriously worn out with your engine. The fact that bystanders notice the amount of smoke leads me to believe this. Going to an unvented oil cap will only increase the rate of damage, as it will essentially disable the PCV system. It really sounds like you need a rebuild. How's your oil consumption?

 

[Joes72/65]

Oh, the vents in the oil filler cap are supposed to let fresh air in, not crankcase vapors out.

 

[blacknail]

I appreciate the comments. I'm a bit like Nick Nolte's character on 48 hours and his sky blue caddy. This convertible is a survivor, and I've got $5K in it. It's a cool car and I love it, but I'm not a show-car kind of guy, and would rather drive it than work on it. (I have a Triumph TR4A for that kind of frustration). The C-code pony's got over 200K on a 289 that is otherwise strong and reliable; the heads have never been off of it as far as I can tell (it has been in the family since 73). If there's a way to stop the smoke and stink short of a rebuild, up for that. If not, then it'll have to smoke and stink until I am forced to part with time and money I don't right now have. Is there a quick fix?

 

[Joes72/65]

Unless I am wrong, unfortunately not. The "smoke" coming out of the filler cap is likely blow-by, which, in the amount you describe, probably means your piston rings are shot.

 

[blacknail]

Thanks, I appreciate it. I didn't answer the oil consumption - 2 quarts per 3K miles. I did more reading about blow by, and did a compression test. Got 30 psi (not 130; specs are 130 t 170 psi) in #1, thought the guage was bad, got 30 psi on #2, thought WTH?, so checked #8, guess what - 30 psi. These 289s must be real hosses to hang in there like that. I guess I'll just have to be glad its still making smoke at this point! On to the next isue!

 

[bassinbob99]

30lbs on 3 cyls? no wonders it smokes..There is a way to stop the smoke other than rebuild, you would have to construct a way to vent the blowby from the valve cover to the exhuast. Useing a nonvented filler cap, drill and braze a fitting and attach a copper tube to filler cap, run it to the exhuast pipe that you will have to drill and braze in a fitting to attach the copper line to. The exhuast will pull the blowby into the exhuast and it will go out the tail pipe.
That being said,,rebuild the engine...LOL

 

[Joes72/65]

It is truly a testament to the ruggedness of the 289/302 design that it can still power a car in such a condition. On the bright side, when you eventually do get it rebuilt, you'll be blown away by the amount of power you will suddenly have!

 

[blacknail]

Thanks, folks. I've done some reading and thinking. I've read a lot about increasing horsepower by selectively changing a few things as long as they're off, anyway, and will re-search the forum and post new questions when the inevitable comes along. Right now, it does sound like a rebuild is in my near-term future, and I am encouraged by the cost of a crate block, not that I'd go that way, though, I want the numbers to match. Right now, I guess I'll just have to smoke more cigars to cover teh smoke and stink part, and run this puppy till she won't start or untilI hear the first signs of a knock.

FYI, I only checked psi in 1, 3 and 8, and figured knowing that was confirmation enough. I suspect that the other cylinders are the same.

stay well, more later!

 

[Cracker289]

I know this is a very old thread, but I had to chime in anyway. The 351c in my old truck is one tired POS with who-knows-how-many miles on it, and my blowby was so bad that in addition to smoking out of the oil fil cap, it was pushing oil out everywhere - out the timing seal onto the crank snout and being slung all over the engine bay. I bought this little dealio called "envalve" which replaces the PCV valve. Its like more than 50 bucks, so definitely not nearly as cheap as the PCV valve it is replacing, but what it does is maintain 6 inches of vacuum in the crankcase, so it sucks all the blow-by back in, which in turn keeps it from pushing out the smoke thru the oil fill hole, keeps the oil cleaner, and just basically kills all your oil leaks. I'm definitely glad I got this, I was seriously considering rebuilding that Cleveland motor because of it, and now instead for 55 bucks I'm just driving it the way it is with no problems. I made at least a dozen trips to a big lumber yard 30 miles away, and loaded that truck down every time, and she just chugs right along working her *ss off; meanwhile I thought this engine was as good as gone!