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Oil Breather Alternative

GuzziMoto said:
As has been said a few times, if your motor blows oil out the breather something is wrong and I would address that. It should not be considered "normal".
It may be an issue with the motor or it may be too much oil in the sump. But whatever it is, it is not "normal".
There is nothing weird about a Guzzi motor. They do not work under different rules of physics and engineering than other motors. And many motors do not have a method of separating oil out of the breather air, yet they don't blow oil unless something is wrong.
Click to expand...

Yeah I'm pretty sure my oil has been over-filled! Checked it cold last night and it was almost to the top of the flat part of the dipstick. Then I went for a ride and checked it warm and it was over the flat section by half a cm...
 
I'm tracking my oil usage. Keeping a written record of it.

Only trouble is with the colder weather I'm not riding very much at all. Mostly short trips for breakfast or brunch is all.

WARRANTY ends in June, so I need to get this figured out so it ain't on my dime.
 
Then something is wrong with your bike. It is not a universal issue, and as such it would not be something that there is a "fix" to.
 
I've decided to venting to the atmosphere and will work with this method and by pass that air box system.

I've got this thing plumb maintaining an oil capture return line to the sump to see if I can capture oil and send it back to the sump. Work in progress. Doing this without any leads going into that airbox. So my airbox is now free of any type lines going into it. No way can oil any longer get into that airbox.

I'll just need to see how well my oil return system works and how much blow by I get. I may end up taking a vent line all the way out the back fender as with the old Triumph's. I think I can keep it out of view under the fender. For now I'm routed up under the tank, will see how much oil film I get under there. If it's too much oil mist...... out the back fender system will be the next step. In the testing phase still. The airbox will not work because I think that the vacuum in the airbox eventually cause issues sucking the oil out of the heads. Being in California I also wonder if oil temperature have something to do with this issue. I have noticed the bikes with this issue all appear to be from hot climates or end up ridden in hot tempertures.
 
sib said:
It would be helpful if you let us know which V7's you're referring to. The '13 and later models (1TB) seem to have this problem sorted out. I've had no oil consumption or loss on my '13 and '16 Stones.
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I'm starting to think this is oil temperature related. I've noticed the people having trouble with this live in hot climates with temperatures that get into the 100's.

For example the temps have been in the 50's the last month, and right now I'm not having oil blow by issues.

Although I did find one bike that went into Death Valley, 115 degree temps, and he didn't have blow by issues, his oil level was at or near the bottom of the stick.

Also the problem was apparent with the 2013 models because Guzzi changed the entire venting system with the 2014 bikes. So this is a known issue and documented with Guzzi aware they have a problem. The 2014 and beyond bikes with the new system are also having the issue, but as I say this is mostly with oil levels near the top line or very hot conditions.

East coast temps, oil in the middle of the stick, and you won't have this issue.

I could probably get any of these bikes into a blow by issue just taking it on a ride in 100 degree temperatures even with oil level in the middle of the stick.
 
elkgrichard said:
....Also the problem was apparent with the 2013 models because Guzzi changed the entire venting system with the 2014 bikes. So this is a known issue and documented with Guzzi aware they have a problem. The 2014 and beyond bikes with the new system are also having the issue, but as I say this is mostly with oil levels near the top line or very hot conditions....
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I'm not sure I agree with these facts, and especially with the conclusion that this is a "known issue and documented". As far as I am aware, the venting system was identical on all '13-'15 V7's (first USA 1TB models). It did change with the '16 V7II ABS models, but we don't really know whether this was because of an attempt to improve it or whether it had more to do with space considerations (e.g., the evap canister was moved up to under the fuel tank). Anyway, since neither my '13 Stone nor my '16 Stone had/have oil loss problems, for me there was nothing to improve.
 
I don't think that change in the venting system had anything to do with creating space. They changed the system to try and isolate the breathing system from the vacuum pressure build up inside the airbox. Just my thoughts on it, who knows what is really going on with this system. Looks like all the companies have had issues with breather systems going into airboxes. I had a hell of an issue with a couple HD's saturating the air cleaners. I end up buying kits to fix both of those bikes. Those bikes had the issue so bad they would foul plugs.
 
If you have a vacuum building up inside your airbox something IS wrong with your bike.
Again, there are thousands of Guzzi's out there just like yours that do not have an issue. While the design may have changed for the newest bikes that does not mean that yours has a design fault. If it did than your issue would be common on all those other Guzzi's out there that are just like yours.
You are grabbing at straws and looking at this from the wrong point of view.
By the way, not only does your V7 vent its crankcase to the airbox, most modern internal combustion engines do the same thing. It in itself is not a problem, even on a HD.
 
GuzziMoto said:
By the way, not only does your V7 vent its crankcase to the airbox, most modern internal combustion engines do the same thing. It in itself is not a problem, even on a HD.
Click to expand...
Some of us are old enough to remember the days before cars had positive crankcase ventilation systems. There would be a pipe coming up from the crankcase with a bit of coarse steel wool at the end to condense some of the oil, and crankcase vapors would simply diffuse out into the engine compartment under the hood, leaving a greasy sheen on everything. If the rings or valve guides were worn, the venting would be more like a smokey cloud than a diffusion. I think there's been a bit of progress since then.
 
GuzziMoto said:
If you have a vacuum building up inside your airbox something IS wrong with your bike.
Again, there are thousands of Guzzi's out there just like yours that do not have an issue. While the design may have changed for the newest bikes that does not mean that yours has a design fault. If it did than your issue would be common on all those other Guzzi's out there that are just like yours.
You are grabbing at straws and looking at this from the wrong point of view.
By the way, not only does your V7 vent its crankcase to the airbox, most modern internal combustion engines do the same thing. It in itself is not a problem, even on a HD.
Click to expand...

I've owned 8 HD's from a Pan head all the way to the twin cams.... and the newer ones the heads vent into the air cleaner which essentially is the air box. That is what gave me fits. I don't know how many times Harley changed that vent system, about like carter has liver pills.

This bikes crank case is not venting into anything except the heads and then the heads vent into the airbox. My bike is now venting out a hose going out the back fender as with the old Triumph's. YUP, I've gone hillbilly.

It appears to me the return hose to the top of the sump from left side of airbox is only for oil returning once the engine shuts off..... since they have a one way check valve that is closed once you start the bike, vacuum operated.

According to my dealer they have bikes showing up with this same issue. They told me to fill the oil level only to the bottom line.

The pressure in the air box is the vacuum pressure, if you don't have vacuum pressure the bike ain't running. You always have pressure going through an air box. That is why venting these vent lines into an air box can create an issue because vacuum creates suction and suction will hyper the breathing of the heads, thus the oil being sucked out of the heads and probably even the sumps.

At any rate my modification to the venting system works well and this is probably all behind me at this point. Hopefully. :)

On another note I've noticed in this weather I'm getting a fair amount of condensation coming out of those head vents, so with a stock operating system you have water getting into that sump from that condensation that is collecting in that air box. Not only that it's blowing that condensation into the engine via the air intake to the motor. Long term that will take a toll.
 
sib said:
Some of us are old enough to remember the days before cars had positive crankcase ventilation systems. There would be a pipe coming up from the crankcase with a bit of coarse steel wool at the end to condense some of the oil, and crankcase vapors would simply diffuse out into the engine compartment under the hood, leaving a greasy sheen on everything. If the rings or valve guides were worn, the venting would be more like a smokey cloud than a diffusion. I think there's been a bit of progress since then.
Click to expand...

The good old days sometimes were not that good. I remember my dads cars having that oil film all over everything under the hood. It kept it all from getting rusty.:)
 
Your air box has three openings, one for each cylinder to draw air in from and one for air to enter the airbox to replace the air being sucked into the engine. If air cannot enter the airbox faster than air is being sucked out you would get a vacuum in the airbox. But that should not happen as air is free to enter the airbox as it is sucked out. Where you do see a noticeable vacuum on a modern running engine is between the throttlebodies and the head(s).
You would be hard pressed to find a modern motorcycle or car that does not vent the crankcase into the airbox.
It is common knowledge that the correct oil level in all but the newest small block Guzzi's is at the low level mark. If you fill it to the high level mark it will spit out the extra oil until it gets down to the correct level. If that is your problem, overfilling, the solution is that simple.
 
OK, thanks for that information because I notice when they want to draw vacuum they always go to the throttle body section.

I stand corrected. :)

Although there is vacuum inside the air box. If you disconnected one of those oil return lines while the bike is running you will notice vacuum will suck your finger if you put it over that hole.

In fact I was reading last night that some of these head ventilation systems do need a little bit of vacuum to clean all of the gases from inside the heads. So I'm going to keep an eye on my new vent system since it's an open to the air with no vacuum assist. A sign of gasses building up in the head will give knock or pinging.
 
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UPDATE.....when vented to the atmosphere and disconnected from that air box the engine will start to knock because gases end up trapped inside the heads and engine. So this ventilation system in fact depends on some vacuum to clear out the engine gases.

I end up putting this thing back to stock specs and the knock went away.

Tod.....for your information and to pass on, this head vent system can't be vented to the atmosphere.... because it depends on vacuum from the airbox to void the engine of built up pressures.

This has really been an education the last couple days. So back to stock, and better to not mess with this thing, it apparently is a highly engineered system and not as simplistic as I had guessed.

Nothing on these new engines car or motorcycle are simplistic as the 50's. Lot of years of engineering data in all of these systems. All for the best and a little glitch here or there better to live with, ignore, whatever.

When I'm done with this bike I'll have a PHD with stupid things not to do.

This was sort of Like the time I tried to put a Barbie play house together without first reading those instructions. Yup. the wife figured it all out because she was reading those instructions, while I was trying to act like she was an idiot and I knew it all. Night before Christmas and alcohol consumption my excuse that night.
 
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Routed the rocker cover breathers to a y barb then off to the rear mud guard (fender?!) and blanked off then sump return.

Not lost any oil in 1500 miles, no mayo anywhere except spitting out of new breather. Plugs also seem cleaner ...
 
I tried that except I had the sump tied into it. I end up with a knocking noise in the motor? Mayo all over the ground behind the bike in the parking spot.

Be aware that the head breathing system may depend on a slight amount of vacuum pressure to relieve gas pressure in the motor. At least that is how this type breather system work on some automotive applications.

I'd be very interested with a follow up on this vent to the atmosphere system, as far as if you are finding or hearing engine knock. As I stated, when I had my system set up that way, as you have done, I end up with engine knock, especially under hard throttle.

Once Iput it back to stock the engine knock went away.??

Someone mention on some other post that lining the bottom of the air box with air filter foam somehow stop the oil from getting sucked up into the intake.
 
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The v7 engines tend to suffer from piston slap, ridden lots of single throttle body v7 and v7 II here and they all have a slight knocking noise below 2500 due to the piston design.

I doubt that the vacuum has any thing to do with the knock. I have my v7 powered TT vented to the air with the sump return removed and have done 3000 UK miles with no problems.

Only though regards the knock I had was did you properly seal the oil feed and return breather holes in the air box?
 
UPDATE... gUZZIv65tt.....I AGREE WITH EVERYTHING YOU SAY.


I went ahead and vented this thing back to the atmosphere and just plug that oil return line as you did. All four of those tits are plug into the airbox now.

Went for a ride, no more piston slap, just a very fine mist, very little oil exiting the head vent line. I just routed it under the bike, all the way over as far as I can get it to the left side by the kickstand. That should keep any oil mist away from the rear tire. If I find I'm getting oil on the rear tire, I'll route it out the rear fender as with the old Triumph Bonneville. I've already got all the hose to do that.

I think most of the oil was being sucked out of the sump into that airbox, since very little mist is coming out of the head vents.

I'll track my oil usage and find out for sure if this is a good fix or not. Either way I'll leave it like this just for the fact it keeps all of that junk out of my combustion chamber, it was not just oil, it was also water vapor.

I think my first attempt with this the lines became plug up with oil from the sump line that I had phased into the vent system. That inturn caused pressure to build up inside the motor, thus the piston slap chit.

If first you don't succeed, try try again, as they say.

These bikes are just not set up right from the factory. This stock venting system was a total engineering joke.

Wire brushed the plugs off, stuck them back in, went for a long ride and they did stay clean for once. Up to this point I could not get a set of plugs to last more then 4,000 miles.

I'm sure glad you came back to this post with that follow up. It solved an issue for me for sure.

Thanks much for the information.

With respect, Rick
 
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Nice one Rick :cool:


Been using that style breather setup for years and years on all my small blocks. The V7 Stone engine I have in my TT was the most shocking, 4000 Miles from new and this was the state of the inlet manifold when I stripped the engine out of the stone.



The inlets, piston crowns and heads were covered in thick oily deposits coming from the breather system. Plugs were never the right colour and worst of here in cold damp rainy UK the amount of mayo getting back in to the sump was worrying

Does make you worry how much damage is happening to the throttle body on the single unit bikes

Only mod I may make is too route the head vents with separate pipes to the rear to increase its ability to breath at some point
 
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