• 4 Stroke Husqvarna Motorcycles Made In Italy - About 1989 to 2014
     TE = 4st Enduro & TC = 4st Cross

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TE449/511 breather questions...

N

New511Guy

Husqvarna
A Class
OK, I've got a couple of questions about these breathers. If you have some input please use basic language, I'm a novice.
1. What is the Breather venting? Is it crankcase pressure from the descending piston? That kind of makes sense to me except that the volume of air fluctuating in the crank case would be equal to the displacement of the engine (450cc per stroke). Breather boxes like the ones I've seen aren't designed to handle that kind of volume or pressure fluctuations. So, is it venting something else... What?

2. Why does it vent to the airbox instead of just venting to the atmosphere?

3. How much oil volume is actually captured and returned to the sump? In, let's say an hour long ride, about how many cc's would the system capture and return? If it's less than 30cc's why not just run the line in front of the counter sprocket and let it auto-oil the chain. Then just check and top off the engine oil before each ride?

4. Ultimately, in layman's terms, what is the advantage of these systems other than helping to keep oil out of the air box?

5. Oh ya, when it says, "In from the breather" does this actually produce both in and out venting? That is, does air/oil actually move both directions in this line or is it a one way vent?

ZipTy Breather.JPG
 
1. The breather vents gases from the crankcase caused by some amount of blow by. Combustion gases leak past the rings and add air/pressure to the crankcase. This needs to be vented so that the case does not get pressurized.
2. The airbox puts some vacuum to the crankcase helping to evacuate the gases. Also probably for emissions.
3. Filling to the stock oil level - not very much should be captured and recirculated. If filling it to more desirable levels, more oil will be pushed through the vent and drain back to the case.
4. The main advantage is you can run more volume of oil. Additionally the hot gases do not degrade the torque limiter which is right by the stock breather location.
5. From the breather is the vent coming from the valve cover. Gases/oil come in this way. Out to airbox is the vacuum source. Drain lets the oil drain back to the case.
 
At the very least, get the breather relocator and run 1150cc of oil. If it turns out you are still getting oil in air filter then its easy to add the tank. TEs which are likely to see sustained rpms on road seem to need the tank, my TXC gets by with the breather relocate, but its dirt only and rarely runs high rpms for a sustained time.

Also using 0-40 Mobil 1 will help.
 
OK, follow up...
1. The increase in old volume works out because some of the excess will just flow through the system rather than being dumped into the airbox if it's overfilled with stock set up?
2. The "Out to Airbox" seems entirely unnecessary. The vacuum assist would be minimal given the pressures that the breather is controlling. A simple vent to atmosphere would seem to work just fine. True? (Given how many emissions regs most of us are breaking anyway.)
 
One gets the breather locater from zip ty racing. In my experience, I have just the breather installed with a t junction; 1 hose down to crankcase, 1 to air box. I run 1150cc -1200cc no problem with no oil in air box. It also seems the 511s have more problems than the 449s but I have zero evidence to support that statement. Maybe the 511 riders are just better, more aggressive riders than us 449ers, lol.
 
New511Guy said:
OK, follow up...
1. The increase in old volume works out because some of the excess will just flow through the system rather than being dumped into the airbox if it's overfilled with stock set up?
The breather hole is relocated to top of valve cover....farther from the oil in the crankcase and lots more volume in the passages to the valve cover to allow the vapor the drop out is my theory...it seems to work.
2. The "Out to Airbox" seems entirely unnecessary. The vacuum assist would be minimal given the pressures that the breather is controlling. A simple vent to atmosphere would seem to work just fine. True? (Given how many emissions regs most of us are breaking anyway.)
Out to airbox is the default arrangement so both ends of the breather are part of the closed engine. Some have vented to atmosphere...WITH A FILTER ON THE END and plugging the vent hole into the clean side of the airbox. I go from Zip Ty valve cover vent to stock airbox vent, run 1150-1200cc of Mobil1 0-40 and get very little oil in airbox
Click to expand...

http://www.ziptyracing.com/breather-vent-cap/
 
N4544D said:
One gets the breather locater from zip ty racing. In my experience, I have just the breather installed with a t junction; 1 hose down to crankcase, 1 to air box. I run 1150cc -1200cc no problem with no oil in air box. It also seems the 511s have more problems than the 449s but I have zero evidence to support that statement. Maybe the 511 riders are just better, more aggressive riders than us 449ers, lol.
Click to expand...


Its true...Ive had both 449 and 511...probably not the awesomeness of the riders, but that little bit more air being pushed by the piston.
 
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