I'm getting some popcorn and pulling up a chair, not that I want to see a fight but the thing I dislike so very much on this or any forum is incorrect information.
Nice to see it all laid out and just the facts.
I'm getting some popcorn and pulling up a chair, not that I want to see a fight but the thing I dislike so very much on this or any forum is incorrect information.
Nice to see it all laid out and just the facts.
I just want to help people out - that's why I take twice as long to work on my cars to pause and take pix. I value experience as much as the next guy, and I can thump my chest too, but I just want to understand what's actually going on, and not read some WAGs or stuff that applies to other engines.
you should have changed you plugs at 100k-miles ... are you sure you didn't have them changed? they should be misfiring like mad by now if they're original (that and/or burning up your coils too)
And like I said, the valves were clean and intake had minimal buildup - you can see where the high quality (Shell) fuel kept the scary oil off the valves and off the inside of my intake:
Presumably, that same fuel somehow made its way into the combustion chamber, where it also kept the pistons clean.
And for those looking for data, here is (reportedly) a used oil analysis on a GM V-8 that went 13K miles on an oil change. Note that it has no fuel in the oil. In fact, "No contamination was found."
On the other hand, here is one with the same engine, reportedly (by the owner) with a catch can, that DOES have gasoline in the oil:
. . . just sayin . . . .
I'm not saying anyone is wrong or anything I just hate when random non-fact based things are thrown out on the forum and it spreads, no saying anyone threw out non-fact, I was just saying.
Now I am getting off topic, sorry, I like to keep threads on topic and not ruin the OP path and topic. God bless the new guys full of questions but start a thread if you want to stray so it is on topic and easy to find down the road when people search, even though they don't search.....
Most factory tunes (as any tuner can vouch for) are rich from the factory as no 2 engines are the same so yes, there is considerable unburnt fuel in todays crankcases.
Fuel savings alone by eliminating oil ingestion into the intake air charge adds up to far more savings than spraying solvents into a engines crankcase or not changing spark plugs when needed.
Every single product I have endorsed (mine or a direct competitiors) has a ton of documentation on the benifits. Dyno comparisons, fuel economy studies, and dissasembled engines to examine, take pictures of, and share with those that do care.
There needs to be no fight, and what you shared is a plus to all, but to nay-say well documented facts is a diservice to all that care about the best for their baby.
If I was the greedy profiteer you claim I would hardley put all the time and effort into what I share and would just push products like the "turbonator"," magic fuel magnets", and all the other proven false smake oil people spend millions on when the research is readily available to see they are false, yet you attack facts as smoke and mirrors.
Correct information is what should be shared on the forums...not false claims that confuse those who truely want to learn.
So, I have listed my qualifications......just list yours so we can see how you came to your conclusions.
I get very few sales from being a vendor on this forum.....propbably less than $200 a month and average $40-60k from the rest of our sales outlets...most in the dealer network.
Any that want specific facts, pictures, and answers in detail on any question...ask. And if this is not what the OP wants then lets start another thread.
"pulling back on the clip and pulling up on the hose end"
I can't get the fitting off. There's an identical fitting that goes onto some sort of port right after the MAF but I couldn't figure out how to get that one either.
Is it some sort of latch? Friction fit? I don't see any pieces inside that move relative to the fitting itself.
EDIT: I can see how it opens up now. Time to put it in practice...
Pro tip: push down the fitting before trying to open the latch. If you try to open the latch if the fitting is stuck upward, it will jam and you will hate yourself. Once it's down, the latch opens easily.
I rate this mod easy-to-almost impossible depending on how generous your breather fitting is. I could not remove the breather fitting since there is no space (on the CTS) to apply or leverage a full body pull, and locking pliers typically have nothing on them that facilitates pulling. I can deadlift 270+ and I could not get the breather to budge (the whole car was shaking, etc.). I did get it to rotate slightly, though.
****ing wire looms press down HARD into your left forearm, too.
And no, other than a bottle of Berryman's or Techron in the gas tank from time to time, no "upper induction cleaning." Like I said, top tier gasoline makes a huge difference in these vehicles. More than one tank of bad gas has caused a no-start due to sticking valves, which some have confused for a broken or slipped timing chain.
I really hate this kind of conflict. I don't have a mile-long pedigree, I'm just a guy that works on his cars. My apologies to everyone else.
Yes it is....and here is my last post giving 3rd party industry technical info on the subject.
Some more good reading:
Crankcase ventilation system
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A crankcase ventilation system is a way for gases to escape in a controlled manner from the crankcase of an internal combustion engine.
This is necessary because internal combustion inevitably involves a small but continual amount of blow-by, which occurs when some of the gases from the combustion leak past the piston rings (that is, blow by them) to end up inside the crankcase.
[hide] 1 Early provisions
2 Road draft tube
3 Positive crankcase ventilation (PCV)
4 Components and details
7 External links
 Early provisions
This section does not cite any references or sources. (April 2012)
From the late 19th century through the early 20th, blow-by gases were allowed to find their own way out to the atmosphere past seals and gaskets. It was considered normal for oil to be found both inside and outside an engine, and for oil to drip to the ground in small but constant amounts. This had also been true for steam engines and steam locomotives in the decades before. Even bearing and valve designs generally made little to no provision for keeping oil or waste gases contained. Sealed bearings and valve covers were for special applications only. Gaskets and shaft seals were meant to limit loss of oil, but they were usually not expected to entirely prevent it. On internal combustion engines, the hydrocarbon-rich blow-by gases would diffuse through the oil in the seals and gaskets into the atmosphere. Engines with high amounts of blow-by (e.g., worn out ones, or ones not well built to begin with) would leak profusely via those routes.
 Road draft tube
The first refinement in crankcase ventilation was the road draft tube, which is a pipe running from a high location contiguous to the crankcase (such as the side of the engine block, or the valve cover on an overhead valve engine) down to an open end facing down and located in the vehicle's slipstream. When the vehicle is moving, airflow across the open end of the tube creates a draft that pulls gases out of the crankcase. The high location of the engine end of the pipe minimises liquid oil loss. An air inlet path to the crankcase, called the breather and often incorporated into the oil filler cap, meant that when a draft was generated at the tube, fresh air swept through the crankcase to clear out the blow-by gases.
The road draft tube, though simple, has shortcomings: it does not function when the vehicle is moving too slowly to create a draft, so postal and other slow-moving delivery vehicles tended to suffer rapid buildup of engine sludge due to poor crankcase ventilation. And non-road vehicles such as boats never generated a draft on the tube, no matter how fast they were going. The draft tube discharged the crankcase gases, composed largely of unburnt hydrocarbons, directly into the air. This created pollution as well as objectionable odors. Moreover, the draft tube could become clogged with snow or ice, in which case crankcase pressure would build and cause oil leaks and gasket failure.
 Positive crankcase ventilation (PCV)
During World War II, however, a different type of crankcase ventilation had to be invented to allow tank engines to operate during deep fording operations, where the normal draft tube ventilator would have allowed water to enter the crankcase and destroy the engine. The PCV system and its control valve were invented to meet this need, but no need for it on automobiles was recognised.
In 1952, Professor A. J. Haagen-Smit, of the California Institute of Technology at Pasadena, postulated that unburned hydrocarbons were a primary constituent of smog, and that gasoline powered automobiles were a major source of those hydrocarbons. After some investigation by the GM Research Laboratory (led by Dr. Lloyd L. Withrow), it was discovered in 1958 that the road draft tube was a major source, about half, of the hydrocarbons coming from the automobile. GM's Cadillac Division, which had built many tanks during WWII, recognized that installation of PCV on vehicles could bring the first major reduction in automotive hydrocarbon emissions. After confirming the PCV valves' effectiveness at hydrocarbon reduction, GM offered the PCV solution to the entire U.S. automobile industry, royalty free, through its trade association, the Automobile Manufacturers Association (AMA). The PCV system thus became the first real vehicle emissions control device.
Positive crankcase ventilation was first installed on a widespread basis by law on all new 1961-model cars first sold in California. The following year, New York required it. By 1964, most new cars sold in the U.S. were so equipped by voluntary industry action so as not to have to make multiple state-specific versions of vehicles. PCV quickly became standard equipment on all vehicles worldwide because of its benefits not only in emissions reduction but also in engine internal cleanliness and oil lifespan.
In 1967, several years after its introduction into production, the PCV system became the subject of a U.S. federal grand jury investigation, when it was alleged by some industry critics that the AMA was conspiring to keep several such smog reduction devices on the shelf to delay further smog control. After eighteen months of investigation by U.S. Attorney Samuel Flatow, the grand jury returned a "no-bill" decision, clearing the AMA, but resulting in a "Consent Decree" that all U.S. automobile companies agreed not to work jointly on smog control activities for a period of ten years.
In the decades since, legislation and regulation of vehicular emissions has tightened substantially, and the toxic emissions of cars and light trucks have decreased substantially. Today's petrol engines continue to use PCV systems.
 Components and details
PCV valve on Ford Taunus V4 engine in a Saab 96, between left valve cover and intermediate flange on intake manifold
The PCV valve is only one part of the PCV system, which is essentially a variable and calibrated air leak, whereby the engine returns its crankcase combustion gases. Instead of the gases being vented to the atmosphere, gases are fed back into the intake manifold, to re-enter the combustion chamber as part of a fresh charge of air and fuel. The PCV system is not a classical "vacuum leak". All the air collected by the air cleaner (and metered by the mass flow sensor, on a fuel injected engine) goes through the intake manifold. The PCV system just diverts a small percentage of this air via the breather to the crankcase before allowing it to be drawn back in to the intake tract again. It is an "open system" in that fresh exterior air is continuously used to flush contaminants from the crankcase and into the combustion chamber.
The system relies on the fact that, while the engine is running under light load and moderate throttle opening, the intake manifold's air pressure is always less than crankcase air pressure, see manifold vacuum. The lower pressure of the intake manifold draws air towards it, pulling air from the breather through the crankcase (where it dilutes and mixes with combustion gases), through the PCV valve, and into the intake manifold.
The PCV system usually consists of the breather tube and the PCV valve. The breather tube connects the crankcase to a clean source of fresh air—the air cleaner body. Usually, clean air from the air cleaner flows into this tube and into the engine after passing through a screen, baffle, or other simple system to arrest a flame front, to prevent a potentially explosive atmosphere within the engine crank case from being ignited from a back-fire in to the intake manifold. The baffle, filter, or screen also traps oil mist, and keeps it inside the engine.
Once inside the engine, the air circulates around the interior of the engine, picking up and clearing away combustion byproduct gases, including a large amount of water vapor which includes dissolved chemical combustion byproducts, then exits through another simple baffle, screen, or mesh to trap oil droplets before being drawn out through the PCV valve, and into the intake manifold. On some PCV systems, this oil baffling takes place in a discrete replaceable part called the oil separator.
During the mid 1960s, substantial work was completed on an entirely independent crankcase ventilation system. The Engine Ventilation System had its own air intake filter, a sizable crankcase gases filter, condensate chamber, and highly engineered air flow valve. The system recycles clean water vapor, filters light oil, and filters air into the intake system before the carburetor, resulting in lower carbon monoxide and hydrocarbon emissions and extended engine oil life. Ford Motor Company made this system a requirement on all its material handling equipment (lift trucks) in 1971. This system was also used extensively on over-the-road diesel trucks and irrigation pumps. The AMA's choice[clarification needed] of catalytic converter made automotive use unlikely.
The PCV valve connects the crankcase to the intake manifold from a location more-or-less opposite the breather connection. Typical locations include the opposite valve cover that the breather tube connects to on a V engine. A typical location is the valve cover(s), although some engines place the valve in locations far from the valve cover. The valve is simple, but actually performs a complicated control function. An internal restrictor (generally a cone or ball) is held in "normal" (engine off, zero vacuum) position with a light spring, exposing the full size of the PCV opening to the intake manifold. With the engine running, the tapered end of the cone is drawn towards the opening in the PCV valve by manifold vacuum, restricting the opening proportionate to the level of engine vacuum vs. spring tension. At idle, the intake manifold vacuum is near maximum. It is at this time the least amount of blow by is actually occurring, so the PCV valve provides the largest amount of (but not complete) restriction. As engine load increases, vacuum on the valve decreases proportionally and blow by increases proportionally. With a lower level of vacuum, the spring returns the cone to the "open" position to allow more air flow. At full throttle, vacuum is much reduced, down to between 1.5 and 3" Hg. At this point the PCV valve is nearly useless, and most combustion gases escape via the "breather tube" where they are then drawn in to the engine's intake manifold anyway.
Should the intake manifold's pressure be higher than that of the crankcase (which can happen in a turbocharged engine, or under certain conditions, such as an intake backfire), the PCV valve closes to prevent reversal of the exhausted air back into the crankcase again. In many cases PCV valves were only used for a few years, the function being taken over by a port on constant depression carburetors such as the SU. This has no moving parts or diaphragm to jam, block or rip like many PCV valves. It also doesn't have a 'one-way' function but the lack of it was never a problem in intake backfire.
It is critical that the parts of the PCV system be kept clean and open, otherwise air flow will be insufficient. A plugged or malfunctioning PCV system will eventually damage an engine. PCV problems are primarily due to neglect or poor maintenance, typically engine oil change intervals that are inadequate for the engine's driving conditions. A poorly-maintained engine's PCV system will eventually become contaminated with sludge, causing serious problems. If the engine's lubricating oil is changed with adequate frequency, the PCV system will remain clear practically for the life of the engine. However, since the valve is operating continuously as one operates the vehicle, it will fail over time. Typical maintenance schedules for gasoline engines include PCV valve replacement whenever the air filter or spark plugs are replaced. The long life of the valve despite the harsh operating environment is due to the trace amount of oil droplets suspended in the air that flows through the valve that keep it lubricated.
Not all petrol engines have PCV valves. Engines not subject to emission controls, such as certain off-road engines, retain road draft tubes. Dragsters use a scavenger system and venturi tube in the exhaust to draw out combustion gases and maintain a small amount of vacuum in the crankcase to prevent oil leaks on to the race track. Small gasoline two stroke engines use the crankcase to partially compress incoming air. All blow by in these engines is burned in the regular flow of air and fuel through the engine. Many small four-cycle engines such as lawn mower engines and small gasoline generators, simply use a draft tube connected to the intake, between the air filter and carburetor, to route all blow by back into the intake mixture. The higher operating temperature of these small engines has a side effect of preventing large amounts of water vapor and light hydrocarbons from condensing in the engine oil.
1.^ a b c d Rosen (Ed.), Erwin M. (1975). The Peterson automotive troubleshooting & repair manual. Grosset & Dunlap, Inc.. ISBN 978-0-448-11946-5.
2.^ Gus Saves a Friend from a Snow Job, Popular Science, February 1966
3.^ NAPA Echlin Service Bulletin: Crankcase and Exhaust Emission Control; February 1968
And from the British:
The usual PCV systems come in two basic flavors, and I'll distinguish them here by referring to them as American and British respectively, due to the prevalence of their use by manufacturers in each country, and in particular in distinguishing LBC's from Detroit iron.
In the British system, which is the more straightforward of the two, manifold vacuum is plumbed directly to the crankcase using a 0.5" or 0.75" diameter line. An orifice of typically 0.030" or less is provided on a line feeding fresh air into the crankcase. Sometimes this line draws vapors from a vapor recovery canister as well, thereby purging the canister and feeding those vapors indirectly into the engine intake, and sometimes this orifice is contained in an oil filler cap, but for the purposes of PCV it functions the same either way. It does however have the potential to either enrich or lean the idle mixture to a limited degree. The manifold vacuum purges the crankcase of blowby fumes. By placing the crankcase under vacuum, a metered quantity of fresh air is drawn into the crankcase through the orifice... at least at idle and part throttle. As the throttle opens and engine load increase, blowby also increases proportionally until at some point the crankcase transitions from vacuum to positive pressure. This may not occur with a new engine in good condition using a larger vacuum line, but it certainly will with an engine having significant mileage. When the crankcase is at positive pressure, nothing changes on the vacuum side other than the volume of gasses going into the intake, but on the orifice side the flow reverses. This is usually not particularly significant due to the small size, but can contaminate the carbon in the vacuum canister over the course of time.
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American systems use a large diameter vent line to the atmosphere, usually running from a valve cover to a location in the air filter housing, and a smaller diameter line to the intake manifold, usually 0.3125" to 0.375" in diameter. This system restricts the amount of combustible air which enters the engine with a PCV valve rather than an orifice, and it is placed in this intake line. The PCV valve is pretty unique in that it allows full flow at low pressure differentials across the valve and a metered restriction above that level. It also shuts off flow in the reverse direction, thereby eliminating the need for a flame trap. This is done by using a shuttle inside the valve which I'll return to shortly, as this is the most misunderstood part of the system.
The crankcase is never under vacuum but can become slightly pressurized. The large diameter vent line allows fresh air into the crankcase and also allows excess blowby to vent into the air cleaner housing through a flame arrestor where they are ingested by the engine, whenever engine loads and throttle openings are great. Under part throttle the PCV valve is open due to the lower vacuum applied across it and the lower level of blowby so most if not all of the blowby is sucked into the intake, drawing fresh air into the engine in the process and also tending to lean out the intake mixture during cruise. During idle there is enough vacuum to shuttle the PCV valve to the metered position and there is usually very little blowby so most of that is ingested along with a small amount of fresh air which is accounted for by adjustment of the idle mixture screws. This is one reason the idle mixture has to be adjusted as the rings wear. Under heavy throttle, although the level of vacuum drops to near zero, should the level of blowby become great enough the shuttle will shut down the flow to the metered level, diverting most of the blowby to the air cleaner and ingesting only a metered amount of blowby through the PCV valve.
The effect of routing these gasses through the air cleaner is to enrich the intake mixture proportionally because the carb doesn't know the difference between fresh air and recycled combustion by-products. So it is interesting that the PCV system helps to give us a lean cruise and a rich WOT, but there is little or no correlation between PCV, carburetor, and volume of blowby other than the initial calibrations of the carb and PCV valve and no mechanism to account for engine wear other than the shuttle valve and idle mixture screws. The interesting thing about this is that the same PCV system is still in use with very little modification on our newer fuel injected engines, although they do have a feedback mechanism in the form of an oxygen sensor.
These systems work quite well normally, but things tend to get interesting once performance modifications are made. Often the PCV systems are unintentionally modified to the point that they can no longer function properly, and this is particularly common with aftermarket intakes, air filters, valve covers, forced induction and the like. It is still possible on almost any performance engine to design and tune for a PCV system that works properly and this is especially important in a street driven car. For all out performance it is less of a consideration and in fact the blowby fumes do dilute the intake charge somewhat, so in these cases a simple crankcase vent is often used, harking back to the early days, with all their attendant inconveniences. Often modifications are made to the system unintentionally, in the quest for more performance and a better appearance, and this can result in problems. One of the most bothersome is pressurization of the crankcase, with symptoms of excess oil sprayed about the engine compartment in various places as it is forced past gaskets and seals. Another is the chance of a crankcase explosion should the need for a flame trap be overlooked. Then of course, any improperly functioning system will have a need for more frequent oil changes, as the combustion byproducts contaminate the oil more rapidly.
For your street driven car there are answers. Sometimes the British system is more appropriate, and sometimes American, but it's best to keep in mind how each one operates and not try to mix the two. When fitting an open element air cleaner onto a typical American 4-barrel carbureted V8, for instance, it's quite easy to install the vent line to the base of the air cleaner inside the element, thereby keeping the system intact. Things aren't quite so neat and clean when fitting a similar air cleaner on a Rover V8, because Rover engines were originally set up with an orifice-type system. Some of these are easily changed over and some are not, depending on the fittings on the rocker covers. Bear in mind that the large vent line of 0.625" or possibly 0.75" in some cases cannot be replaced with a 0.375" hose, or even two of them. Flow increases by the square of the diameter, meaning that a 2" pipe flows four times as much as a 1" pipe. So you would need four 0.375" lines to match one 0.75" line. If your valvecovers do not have the proper fittings and you are not willing to add larger ones to them then you may need a larger line to the crankcase in an alternate location. Early SBC's had a vent line that went through the block web behind the intake manifold. A large diameter tube rising from the pan may be another option. You might use the mechanical fuel pump mounting boss. Or you may be able to use the orifice system, bearing in mind that using smaller lines will cause it to operate under pressure more than it might otherwise. This may require recalibration of your carburetor due to the differences mentioned above, or it may be possible to find a suitable carburetor calibrated for the orifice system, since some British cars were available with a four barrel carburetor. There are other cases where an orifice system is a good choice, such as any induction system where the throttle body is at the inlet of the system. This might be the case with an IR setup or where an engine is supercharged. In these situations there is no practical way to locate the vent tube, and therefore no way to ingest the excess blowby fumes. The solution is to port the crankcase to manifold vacuum (or inlet vacuum in the case of a blower) and use the orifice to restrict flow into the crankcase and subsequent leaning of the intake mixture. It is worth noting here that often EFI systems take control of the PCV system, such as by including a purge valve for the emissions canister, allowing options such as pulling fresh air in at idle to give more precise control of the mixture. Some of these systems may be able to divert PCV intake on WOT for maximum power output. WARNING: All lines from crankcase to intake system must have some form of flame arrester! To overlook this is to invite a crankcase explosion, which in the best possible scenario will have you replacing your lifter valley pan.
Finally, we have the alternative systems, the most familiar being the collector scavenger tube. These are really not suitable for a street driven application because of two things: mufflers, and the fact that they do not work well at idle. For racing it's a good idea, but once you add the restriction of a muffler you have created backpressure which will reverse the flow in the scavenger tube and make the system ineffective. Another option is an external scavenger pump. These tend to be a more complicated solution, but are another possibility that may have merit in special situations. Theoretically it would be possible to evacuate the crankcase using positive pressure and this would tend to lead to seal problems, but if those woes were overcome one might even find a way to route forced induction through the crankcase on its way to the cylinder, provided an adequate air/oil separator were designed. Two stroke engines inherently use this principle, simply burning the oil as they go.
So that's the basic lowdown. No doubt there are details that I've left out but it's enough to give the average person the picture. Hopefully it's enough to help sort through the tangled mess and maze of confusion that typically surrounds these systems
Why didn't you just post the links?