[tooseevee]

Too dark and too damned cold for photos. But, I think many would agree that "not where a breather hose should be"  is the operative phrase here, since it arguably shouldn't be where it is on mine at all. You see, in the final model variants of the Iron Barrels and later their successor AVL engines, the breather outlet was moved from the left-hand of the crankcase, where both The Lord and Redditch intended, to the inboard side of the timing case, with a second inlet port placed nearby as well. The outlet hose was routed to the bottom of a kind of catch can canister, within which was affixed an upward-pointing duck bill type check valve (kind of like a whoopee cushion valve). Just a bit higher up on the catch can, coming off the side, was an outlet that connected to a hose than ran back down to the aforementioned inlet port. This was to allow any condensate to flow back into the crankcase via the inboard side of the timing case. Still higher up in the catch can canister was yet another outlet on its side connected to a hose that ran into the inboard side of the air filter housing. This was to recirculate the vapors from the breather back through the carburetor and into the combustion chamber. The whole rigamarole was a last ditch slapdash effort intended to reduce emissions in this aged engine design. The problem is that if the return hose clogs or the little duckbill valve goes bad, both of which are likely after a time, then the whole goofy catch can affair overfills and begins spewing oil into the air filter, fouling it. A previous owner, presumably afflicted by this, had removed the hose on mine from the catch can to the air filter housing, and ran a longer one down from the can to near the center stand instead, just dangling there open to the ground. This is where on occasion most of the contents of my oil tank would suddenly sploodge out onto the ground below the bike. Replacing the catch can system with a simple hose sloped upward from the breather outlet to a KrankVent type check valve tucked high up behind the battery, with a hose from it down towards the ground cured mine about 10,000 miles ago. I just capped off the old inlet ports on the timing and air filter cases with wine corks. It's been sploodge-free ever since.

If you really need some pix, lemme know. Maybe tomorrow...

           Geez, Louise, I'm aware of all that. I got rid of all that stuff long ago when I first got the bike back when Pete Snidal was still on these forums. It had all the hoses and tubing and the friggin' PITA "catch can".

            The sentence that caused me to write (and ask for a picture) is in your Reply #26 where you say you have your breather hose connected to "the existing later style outlet on the inboard side of the timing case". If you indeed have your breather hose connected to the fitting on the inboard side of the timing case, that would be incorrect.

            The breather hose fitting is on the horizontal surface of the cases (oil tank), the other (inlet) fitting is on the vertical inboard surface of the timing case..... well, both of them can be seen in Adrian's picture. 

            My breather hose is connected to the fitting that points straight up out of the oil tank just inboard of the alternator wires and runs in a big loop up and over and then down between the downtube and the rear fender and ends in a duckbill. The inlet fitting on the inboard side of the timing case is sealed off.

             


           

[Enfield Pro]

This is one crazy "introduction thread", one of the mod guys should consider splitting it.

[Adrian II]

But we like off-topic... 

Until this thread gets an administrative beating, my picture was meant to show the non-electric start drive side, but for the record as far a breather mods go, this one had the breather pipes from the primary and the back of the timing chest plugged off at the hose ends, with just the breather union sticking up out of the oil tank still in use.

You can see the short piece of 90 degree bend rubber hose salvaged from the original breather system, the alloy non-return valve (10GBP from Henry Price?) and a longer chunk of 1/2 inch rubber hose which ran to the end of the rear chain guard. It worked just fine, the only issue being where the bike would choose to manifest the odd dribble of grey goo, usually when parked up at the supermarket car park.

Iron Barrel and AVL Bullet owners have tried all sorts of breather mods down the years.

A.

[ace.cafe]

Okay, I am going to explain the Enfield engine breather system one more time, since it has been years since I did it last, and obviously it needs it again.

The breather system is an active type system which is driven by pressure differentials.
The main driver is maintaining a low pressure in the crankcase sump area. The piston is the pump, and the duckbill(or other non-return valve) is the valve.
When the piston comes down, it pushes air out the breather tube and duckbill, so that air pressure is not significantly increased by its downward movement. Air is displaced, leaving a smaller volume of air in the crankcase.
As the piston goes back up, the duckbill tip closes, and prevents air from coming back inside, thus lowering the local air pressure inside the crankcase area.
This system is not perfect, some pumping losses occur, it does not drastically lower the crankcase air pressure, but it does an okay job for its intended purpose.

We see that the breather tube is about 7mm - 8mm, and the little hole between the crankcase and oil tank is about 3mm. These are metering holes, so that the air goes more easily out the breather tube, and not into the oil tank much. The breather tube is the much easier path, so it goes out that way.

With the crankcase pumped down to a lower pressure, it pulls some air and fumes in from the oil tank via the 3mm hole there. This sets up a cascading effect that pulls fumes in from the timing chest, tappet area, and rocker boxes. It all travels in the direction of that lower pressure in the crankcase. This evacuates the fumes from the entire engine in a continuous circuit which is designed that way. It works.

Efforts to change this pathway will circumvent the intended design, and the factory unfortunately did that when they instituted the later breather on the top of the oil tank. It does not work correctly because of reasons that I just explained, and that is why we convert back to the original type breather when possible.

[tooseevee]

But we like off-topic... 

Until this thread gets an administrative beating, my picture was meant to show the non-electric start drive side,

Iron Barrel and AVL Bullet owners have tried all sorts of breather mods down the years.

A.

         We are not off-topic. He asks about breather mods in his very first post.

          And I only referred to your picture because it shows the two fittings we're talking about. My breather is set up the same way and you know that. I have ONE hose out from the breather with a duck bill on the end. The timing case fitting is plugged off.

           Why do I always end up the bad guy here when all I'm trying to do is help and point out details. The way I read Bilgemaster's sentence (which I QUOTE - go read it) it seems like he says his breather hose is connected to the timing case fitting. That would appear to be incorrect to me and all I wanted was clarification for others, not for me. That is ALL I questioned, that ONE sentence, and I get a lecture on breather systems which is OK I guess. I did the mod to mine years ago as you know and got rid of the "sploogy" friggin' catch can and all the hoses and it has worked perfectly since, but I guess I'm wrong again.

            I'm sorry. I've been on these forums quite a while and I really just try to help and I get zero back up and remarks about being off topic when the original poster asked about this very subject.

[Enfield Pro]

           Why do I always end up the bad guy here when all I'm trying to do is help and point out details. The way I read Bilgemaster's sentence (which I QUOTE - go read it) it seems like he says his breather hose is connected to the timing case fitting. That would appear to be incorrect to me and all I wanted was clarification for others, not for me. That is ALL I questioned, that ONE sentence, and I get a lecture on breather systems which is OK I guess. I did the mod to mine years ago as you know and got rid of the "sploogy" friggin' catch can and all the hoses and it has worked perfectly since, but I guess I'm wrong again.

            I'm sorry. I've been on these forums quite a while and I really just try to help and I get zero back up and remarks about being off topic when the original poster asked about this very subject.

I'm not trying to yuck your yum. I mentioned splitting the topic so anyone looking for breather info can find it with ease. They my not consider looking in a thread titled introduction.

[Tarnand]

I'm not trying to yuck your yum. I mentioned splitting the topic so anyone looking for breather info can find it with ease. They my not consider looking in a thread titled introduction.

Well, it is actually may fault - see Reply #7 on: November 08, 2019, 02:07:01 PM.  I started and it began living life of its own.   

[Bilgemaster]

First off, Tooseevee's quite correct in that my later-style breather hose outlet is not coming off the timing case as such, but rather off the nearby oil tank, I suppose. I only described its outlet location as "inboard side of the timing case" in order to contrast its location, generally speaking, with the older traditional location from off of the left-hand side of the crankcase.

As it was a fine cool morning, as requested I got off a few shots of the key elements of my current setup, as attached below.

• In the first pic both the inlet and outlet port locations are shown, below and to the left and right respectively of the cylindrical thing containing the ignition's timing workings. The now-unused inlet is shown capped off with one of those newfangled plasticky type wine corks from the cheap stuff we enjoy at Chez Bilgemaitre that I sort of drilled out a bit to fit over the port, and is held on with a hose clamp. The outlet to stage right (aft, or rearward) is shown fitted with the original equipment black outlet hose with its 90 degree bend at its end mounted to it, also affixed with a hose clamp. The far straight end of this hose was trimmed just a bit, since it was a bit ragged, and fitted to the inlet side of the KrankVent knockoff shown in the next photo. The sloping angle of the hose from the breather outlet up to the KrankVent is about 45 degrees.
• The second photo shows the shiny KrankVent doodad, just sort of tucked in there behind the battery. I found no need to secure it up there. Like the Bilgemaster himself, it seems perfectly content to just lay around and blow hot air
• The third pic is possibly NSFW nor appropriate for mixed company or sensitive persons, displaying as it does the "business end" of my long greasy breathy urethra, running downwards from the outlet end of the KrankVent, dangling manfully, as it does, low below the center stand pivot. Don't worry, it's just the tip!

I'll be in my bunk...

[Adrian II]

Why do I always end up the bad guy here when all I'm trying to do is help and point out details.

Forum Bad Guy?    If we even have one, you don't fit his description, tooseevee!

A.

[fernf5]

Well, this may have drifted a teeny bit sideways Could I share something (change the subject) that just happened to my new to me bike while I was otherwise occupied and you all were "speculating"? I'll bet something like this has happened to a lot of us. I appreciate Tim's point  about someone looking for info at a later date so maybe a new thread on these kind of things/tales?
While out on a test ride the other day after retarding my timing and enriching the  mixture to get rid of some minor ping I have it dawned on me that I was hearing a nasty sound. I slowed down to listen and used the throttle to change the RPM to better hear the noise. Man, it was a nasty noise, somewhat like I imagined a bent push rod or broken rocker arm, something really bad you know? Limped home, listened to it in my driveway convinced that it was catastrophe. Much wailing and gnashing of teeth later and still thinking it was bad I parked it deciding to look at it later. Pretty glum evening and then today I went to look again. I warmed up the bike and got down on the right side with my stethoscope and was gunning the throttle when I thought I saw the exhaust header vibrate and move in and out right where it enters the exhaust port. It has one of those aftermarket heat rings like on the old bikes with an 11mm nut that tightens it. It just so happens that this was the area I heard the noise coming from. The ring was actually vibrating. Not the header. Tightened it a turn or so and went for a ride thinking "No Way" was that it! Well, I never heard the noise again. These bikes REALLY vibrate I'm finding out....like nothing I've ever experienced.

[ace.cafe]

The severity of vibration varies from one bike to another.
It comes down to how well the factory trued the crank that went into your bike. We have seen some that were as much as .007" out of true when we removed them for rebuilding. If trued to about .001" run out, they can run surprisingly smooth.

[Bilgemaster]

The severity of vibration varies from one bike to another.
It comes down to how well the factory trued the crank that went into your bike. We have seen some that were as much as .007" out of true when we removed them for rebuilding. If trued to about .001" run out, they can run surprisingly smooth.

Ace: I've read elsewhere in this Forum that much vibration can sometimes be ameliorated by some pretty straightforward-sounding technique of slackening and then somehow properly "centering" and retorquing certain engine frame mounts and perhaps also the headsteady, with possibly some additional mod thereof mentioned. I seem to recall that some part of this "engine mount tuning" was performed while the engine was running. It might have pertained to UCE-engined Bullets. I honestly don't recall exactly. But could that also be the case with the older models? Could allowing the engine mounts to center or settle themselves into a more balanced relation to the frame possibly help?

My Iron Cylinder vibrates a bit, sure, but only rather pleasantly. Unlike "fernf5", I'd never come close to characterizing it as "like nothing I'd ever experienced". Compared to my old BSA Victor 441, which would rattle the fillings from your teeth, my Bullet's more of a soothing "thrumming".

I seem to also recall mention that simply a loose or broken headsteady can cause excessive vibration, but again I cannot now recall if it was referencing a UCE or an older model Bullet. Still, a wonky headsteady might be just the likely culprit or stressor to shake out an exhaust pipe from the head, as with "fernf5's", yes?

[fernf5]

Guys thanks for your thoughtful and informational replies. My writing and communication skills leave a lot to be desired and of course this medium (email) lends itself to misunderstandings. I wasn't looking to debate how "vibrationy"  an RE is compared to anything. Just interested in hearing general motorcycle tales and solutions. Anyway, the vibration stuff is good info!

[Bilgemaster]

I did a bit of rummaging through the Forum archives, and this might be one of those threads I recall describing that technique of loosening and tightening the engine mounts to possibly reduce vibration:

https://forum.classicmotorworks.com/index.php?topic=7829.msg300199#msg300199

Sure, it was posted in reference to an over-vibey UCE, but the poster, 'Arizoni' is one of those guys here who really seems to know his shit, and he writes that the technique's been used "for years and years". So that might bode well for your over-energetic Iron Barrel.

In the meantime, I'm hoping on "fernf5's" behalf that some other folks from the A-Team, not just bodgers like me, will chime in here.

[ace.cafe]

I did a bit of rummaging through the Forum archives, and this might be one of those threads I recall describing that technique of loosening and tightening the engine mounts to possibly reduce vibration:

https://forum.classicmotorworks.com/index.php?topic=7829.msg300199#msg300199

Sure, it was posted in reference to an over-vibey UCE, but the poster, 'Arizoni' is one of those guys here who really seems to know his shit, and he writes that the technique's been used "for years and years". So that might bode well for your over-energetic Iron Barrel.

In the meantime, I'm hoping on "fernf5's" behalf that some other folks from the A-Team, not just bodgers like me, will chime in here.

Yes, the bolt loosening trick can work, but it only really works if the engine was tightened into a bad way to begin with. It is always worth a try, because the engine vibrations are intended to be resolved into the frame structure. So that is an option which may help.

A loose or broken head steady WILL cause severe vibrational havoc, so be sure that is tight.