I have a smoking problem with my 327. It never smoked before, but after I went with my 2 fours, closed valve covers, roller rockers and heftier springs, it smokes like a freight train. Now, to understand more, the way the engine had been done by the previous owner, they removed the baffle in the lifter valley and the road-draft tube, put on an intake without an oil fill tube, and installed open valve covers and ran a pcv system. I went back with the original design...well, half of it...I have an oil fill tube with breather, but no valley baffle or road draft tube. I am thinking that it still can't breathe or exhale all of the oil vapor properly and it is pushing into my cylinders and being shoved out my exhaust. Some have told me that I am correct and others that I am completely wrong...because "everybody removed the baffles and draft tubes 'back in the day.' " All I know is that the valve seals are good, rings are good (great compression and there is NO oil fouling on any of my plugs), and it didn't smoke before. It is a 64 model year small journal. Anyone have any ideas? I would greatly appreciate your input.
Put a pcv valve in the back of the intake where you don't have to cut your valve covers up, because your problem is directly related to crankcase ventilation. If you search there's a pretty funny tech thread about how to do it on a SBC, think it was started by stickylifter. But regardless of all the naysayers in that thread, what he did is what you wanna do. good luck
Chevy had PCV setups that didn't require mounting into the valve covers. You should put the baffle back in the block and run one from the road draft tube boss...besides...that will give you a chance to inspect the sealing of the new intake to the heads! You might want to verify that you have undamaged O ring valve stem seals on the valves now as well. I cut some up on the first SBC I put together not knowing the right procedure to install them. It's obvious when you think about it, but funny things can happen when your rushing! Umbrella seals are more user friendly in my opinion...
Just for kicks. Is it BLACK smoke? The 2 fours the problem? A freeze plug instead of a road draft tube, and a tube in front of the intake's fine. Maybe oil sucked up an improperly sealed intake gasket from the lifter area.
Thats asking a lot from a single breather. More than GM was willing to ask, as they had either a road draft tube OR a PCV to augment it! Besides...you'll end up with oil everywhere over the top of the engine if its driven much. With the newly replaced intake and new valve springs, I'd be checking those areas first for seal damage...THEN I'd hook up a proper PCV system to keep sludge buildup/oil vapor under control, even if it wasn't the main problem with oil burning.
nahh, its light blue. its burning the extra gas really well, and all the plugs show that. but i can triple check the bolts around the intake gasket...never know what you might find.
actually, i DO have a lot of oil on top of the engine after i drive it....with 4:11 gears and a 400 turbo, it really pulls the rpms on the highway...and i bet thats all coming out of the tube....hmmmmm. i agree that it needs something more. i am going to look into putting the pcv without cutting my covers, and if i cant find what i am looking for, i will go ahead and pull the intake, inspect everything, and put in the baffle and road draft tube. a little blow by never bothered me, just as long as it isnt coming out of my pipes!! haha
Unless your motor's FUCKED, it's NOT asking a lot of that breather. You guys with 6 Moon breathers on each valve cover, one in the front of the intake, AND a road draft tube crack me up! If the rings are even CLOSE to doing their job, how much crankcase pressure you think's in there, that a 1 1/4 wide open tube can't handle? Are you fucking kidding me? NEWSFLASH- the only reason the fucker's even THAT big, is to provide an easy place to add engine oil! NOT because the motor NEEDS it to release pressure. You don't want oil all over the motor when using a front tube and NO PCV? Stick some Chore Boy scrubbing pad in the tube, and pull it out to wash it every time you add oil. If that don't do it. Put RINGS in it, yours are CRAP. Peace out
So tell me...how did you get your handle???? Hahahaha Despite you being right on not needing 6 Moon breathers, I don't think GM overdid it using a single breather AND a road draft tube or PVC system. True on the size of the oil fill tube though... A closed PCV system that has a separate cap on a valve cover vents thru a 1/2"(?) rubber hose to the closed air breather housing. It's just air and vapor... I don't think his oil burning problem is draft tube related anyway. I'm leaning towards the intake gaskets and/or valve seals he worked on...just like you! But that doesn't mean the engine doesn't need more ventilation than it has now. It ISN'T about blowing oil around anyway, although it does help prevent it...it's about helping to evacuate condensation as fast as possible to stop sludge from plugging the engine and preventing proper drainback of oil from the heads at worst...or at the least making checking your dipstick a total pain in the ass because sludge has blocked the tube, thus making a reliable reading impossible. Lets face it...most Hot Rods are short trip vehicles so proper warmup can be a problem. Anything that helps remove condensation from the engine is a bonus. Bottom line...it HELPS keep that good engine from becoming CRAP ahead of its time and that makes it worthwhile to have. The road draft tube is itself located to pull air from the breather thru the engine...just not as effectively as a PCV. Peace out...ahhhh....Happy trails!!! LoL
Yes, i believe the road draft systen created a slight vacuum under the car to "pull" fumes from the crankcase and expell them under the car so's it don't stink inside the car. The front tube is the air inlet, as well as a place to add oil. I suppose, by the multiple carbs, i "ass"umed this was an open motored car with no worries about fume/stink inside the car. No, GM did not overdo the road draft system. Before the closed system (PCV) the crankcase needed to breath. If it were ONLY the front tube (needed to add oil), fumes would smell up the interior of the car. I guess my point got lost about not needing as much ventilation as some would think. How'd i get my nickname? HOW IN THE FUCK DO YOU THINK? Kidding. I wrote it that way in an effort to voice my point with a degree of conviction.
I told you guys I got a great deal on these valve covers, I didn't put breathers on both sides someone else did...lol
There was a year or two (between road draft tube and PCV in valve cover) that Chevrolet used a PCV valve that screwed into the back of the carb and was tied into an adaptor that took the place of the road draft tube. It still used the baffle in the valley and the filler/breather tube on the front of the intake.
Those outboard breathers are in direct path of oil squirting out of rockers. They, therefore are a great source for spare oil on road trips. hahaha
THAT would be a good one to duplicate here. The effectiveness of a PCV (which i'm a big fan of) and not cut the valve covers. I've also seen the PCV screwed into the side of the front fill tube and a CLOSED cap (road draft tube now to air cleaner base)
Hahahaha...you don't need a PCV system OR a draft tube with that IBB41. I bet theres a cross breeze blowing thru the crankcase when the engine isn't even running!!! LarryT...thats the one I'd use if I had the road draft tube hole in my block. The valve cover mounting is better for full venting but solid covers with no hoses are Sooooo much nicer looking. Groucho...NOBODY is ever gonna doubt your conviction! TRUST me! LoL (Love the coupe BTW...the proportions of a channelled Deuce just do it for me. Later...)
haha...well, i can appreciate your conviction, and understand your point, but i did a compression check and leakdown and everything was fine, so i gather that the rings are just fine. also, it didnt smoke before i changed everything. i am gonna pull the intake, check the intake gaskets and add a pcv somewhere. thanks for your input, i appreciate your straightforwardness.
I blocked them off allready, I just didn't understand why they were even there...lol ......nice one Hackerbill
Change to umbrella seals, they work, they're cheap, they're easy to install. You don't even have to pull the heads!
Do they fit ok with dual valve springs? I wanted to use them on my 462" Buick with K-B dual springs, but ended up using Perfect Circle Teflon seals instead. The Buick umbrella's were too large to fit within the inner spring. The PC Teflon seals are working fine, but the umbrella's still appeal to me.
Not sure if this will help, but maybe. Home-made angled fitting just left of the black grommet replaces the PCV valve. Shown here is a home-made billet aluminum air/oil separator. Note the SBC PCV valve on top of it. Idea is to separate oil from the air and allow the oil to drainback at low speeds and when the engine is off. It works very well at high RPM and highway driving. Especially so since there is no baffle within the Buick engine's valley - a temporary thing - and the original PVC valve location had the pickup end in a swirling air/oil mist. Fresh air for the crankcase is picked up from within the filtered air area of the air filter. There's a more complete article with more pics here on the HAMB, but this shows the basics.
The Jalopy Journal
