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Traveljerry, is this a commercial kit, or something you have put together?travelerjerry said:Kool_Biker said:
The canister is cool.
Cheers, Aris
Leaky valve covers
- Thread starter Kool_Biker
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The canister is cool.
Cheers, Aris
http://www.ebay.com/itm/VMS-ALUMINUM-OI ... ed&vxp=mtr
I got one of these to install this fall. It has two inlets and one outlet on top. The inlets will be one for the breather from the oil tank and one for the crankcase breather. I was hesitant to vent the crankcase breather to a catch can because if there's a lot of oil in the cases it will be be driven up the breather line more than the oil pump circuit before the cases are clear. I put an oil line valve to stop the 'wet sumping' so now I think it's safe to to run it to a catch can. The water and corrosive chemicals that come and out of that tube into the tank don't look like something you'd want to recycle into the engine over and over.
I was thinking about replacing the outlet air cleaner on top of the can with a line to the intake manifold. The catch can has baffles. Assuming the amount of oil/water going into the intake is minimal then the only thing left would be blow by. I wonder if it's significant. I wonder if the crankcase breather and the vacuum from the intake would have an effect on the oil pressure? I ran a crankcase breather valve and a tube from the intake valve cover to the intake tract without any problem. I put a one way valve in the hose so the engine couldn't pull air/gas into the crankcase.
Kenny Dreer ran an external line to replace the oil drain circuit in the cylinder to the time case along with a line from the intake valve cover. The pic's I have seen don't show where it went.
If you are using stainless nuts on the valve covers they can chew up the studs to the point where they strip the threads right off. I took one off recently and the threads came off, they looked like a helicoil.
I got one of these to install this fall. It has two inlets and one outlet on top. The inlets will be one for the breather from the oil tank and one for the crankcase breather. I was hesitant to vent the crankcase breather to a catch can because if there's a lot of oil in the cases it will be be driven up the breather line more than the oil pump circuit before the cases are clear. I put an oil line valve to stop the 'wet sumping' so now I think it's safe to to run it to a catch can. The water and corrosive chemicals that come and out of that tube into the tank don't look like something you'd want to recycle into the engine over and over.
I was thinking about replacing the outlet air cleaner on top of the can with a line to the intake manifold. The catch can has baffles. Assuming the amount of oil/water going into the intake is minimal then the only thing left would be blow by. I wonder if it's significant. I wonder if the crankcase breather and the vacuum from the intake would have an effect on the oil pressure? I ran a crankcase breather valve and a tube from the intake valve cover to the intake tract without any problem. I put a one way valve in the hose so the engine couldn't pull air/gas into the crankcase.
Kenny Dreer ran an external line to replace the oil drain circuit in the cylinder to the time case along with a line from the intake valve cover. The pic's I have seen don't show where it went.
If you are using stainless nuts on the valve covers they can chew up the studs to the point where they strip the threads right off. I took one off recently and the threads came off, they looked like a helicoil.
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Kool_Biker said:Traveljerry, is this a commercial kit, or something you have put together?travelerjerry said:Kool_Biker said:
The canister is cool.
Cheers, Aris
http://www.ebay.com/itm/Black-Billet-Al ... 21&vxp=mtr
It's connected to the oil tank vent.
Nater_Potater
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They did this very thing on car engines starting in the sixty's, and, while I like the idea for the Snortin, there's one major issue you have to deal with: during idle/light cruise, when the need is the lowest, is the same time that the draw (manifold vacuum) is the greatest. Conversely, when you're on the loud pedal and needing extra draw for all of the extra blow-by, the vacuum is gone. If you were to merely hook your catch can to the intakes with a hose large enough to take care of the blow-by during acceleration, you'd introduce a manifold leak of epic proportions during the cruise realm. Cagers took care of this fairly successfully by applying the PCV valve, but that's another maintenance item and something else to try to hide away. Typically, they stick open, which makes hell of your attempts at adjusting the idle.rpatton said:
When it comes down to it, the only reason auto engines routed their fumes to the intake is to ensure that there was no way the fumes could escape, unburned, to the atmosphere. I recommend venting the can into the air filter which pretty much ensures any vapors will get picked up by the engine without the worry of upsetting the intake manifold vacuum. The only caveat to this would be the concern of what oil mist does to paper air filters, but your catch can should coalesce those out before getting to the filter. If you are using the stock air filter, it should already have that available (at least, it does on my ’74).
Kool,
The XS breather is one of the best mods I did to my 850, the joints stay bone dry now, even after a 500km week-end thrash. They are that good that you can ride along with the nuts off the rocker covers, ask me how I know, duh. But seriously I did this once, I had not done the nuts on up on the exhaust rocker covers and noticed a rattle at idle, it was the rocker cover being pulled and released against the gasket surface. The trick is the reed breather creates a negative pressure in the crankcase, so oil is sucked in, not blown out at every joint.
I fitted the XS breather to the rear of the air box, the part that bolts to the battery carrier, and plumbed the crankcase breather through the valve, the other end going to the oil tank as per original.
Best $18.00 spent to date.
Cheers Richard
The XS breather is one of the best mods I did to my 850, the joints stay bone dry now, even after a 500km week-end thrash. They are that good that you can ride along with the nuts off the rocker covers, ask me how I know, duh. But seriously I did this once, I had not done the nuts on up on the exhaust rocker covers and noticed a rattle at idle, it was the rocker cover being pulled and released against the gasket surface. The trick is the reed breather creates a negative pressure in the crankcase, so oil is sucked in, not blown out at every joint.
I fitted the XS breather to the rear of the air box, the part that bolts to the battery carrier, and plumbed the crankcase breather through the valve, the other end going to the oil tank as per original.
Best $18.00 spent to date.
Cheers Richard
I don't understand those who fight using a crankcase reed type breather valve. Drilling holes in valve covers, catch cans (isn't the oil tank a big catch can), special crankshaft oil seals, special gaskets, special sealants, instead of getting rid of the pressure that's causing the oil leaks in the first place.
Evidently Jim Comstock and Matt Ranbow think reed type crankcase breather valves are a good idea. That's good enough for me.
Evidently Jim Comstock and Matt Ranbow think reed type crankcase breather valves are a good idea. That's good enough for me.
DogT
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For me it's not as simple as adding a one way breather. I tried the Comstock sump breather, but because of the brace on my early bike, it wouldn't fit. It's also not an easy thing to pull the engine apart and drill the holes needed plus adding the valve. I've found that I can cure my problems with silicone on the valve covers and a ball valve to prevent wet sumping. I guess too much oil sitting in the crank case produces lots of leaks, I know that it's probably not great for the cam, but it's the best I can do for now. If the engine comes apart, the breather is the next thing and maybe even the ludwig cam trough. As it sits a lot, and I have no drips, it works for me. My biggest leak is the oil sloshing out of the tank around the filler cap, I seem to have a problem sealing that, but I can clean that up with a wipe after every ride.
Not every one is in the same boat.
Not every one is in the same boat.
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I just stuff some paper towels around the oil tank cap, I'll need them when I check the oil anyway, they serve two purposes.
Yeah, any reed valve on the sump will help contain the weeping, no matter where. Figure that you have 750 cc of continuous pumping. vacuum-pressure-vacuum-pressure and so on and even if the reed captures a small percentage of the pressure volume, then you'll have negative crankcase pressure.
Yeah, any reed valve on the sump will help contain the weeping, no matter where. Figure that you have 750 cc of continuous pumping. vacuum-pressure-vacuum-pressure and so on and even if the reed captures a small percentage of the pressure volume, then you'll have negative crankcase pressure.
DogT
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Yeah, I've thought about other gaskets for the oil tank cap, I've got 2 cork gaskets in there right now. I may try a rubber or silicone one and see what happens.
As far as adding a PCV in the breather system, you need to realize that I've got the breather off the timed cam end and it's a tiny hole to start with. It's not as simple as adding a PCV to the breather, it's already limited and that dumps into the central oil tank which is already problematical. I've been informed that the timed breather actually works, just not when at highway speeds. And actually adding one that may work would involve drilling into the space where the magneto used to reside. At least that's what I've been lead to understand, plus it's not very effective unless extra holes are drilled from the timing chest into the crank case. Plus the oil tank breather goes directly into the air filter, which in it's original state drips oil down on the air filter then the gearbox and you can imagine where it goes from there. Adding a catch bottle to the oil tank breather has stopped that issue. I know some with the central tank don't have this leakage problem, but it may be that they start their bike every day or their oil pump wet sumps a lot less than mine.
I've taken the path of least resistance and so far it seems to work. I'd love to put the Comstock breather on or block the timed breather and install a proper PCV in a place that may make a difference. But until I take the engine apart, it's working for me, that is, it's not leaking and the silicone on the valve covers is the least of the issues. At least I can re-use them, I just have to add a bit of silicone to the studs and associated washers when I take them off.
As far as adding a PCV in the breather system, you need to realize that I've got the breather off the timed cam end and it's a tiny hole to start with. It's not as simple as adding a PCV to the breather, it's already limited and that dumps into the central oil tank which is already problematical. I've been informed that the timed breather actually works, just not when at highway speeds. And actually adding one that may work would involve drilling into the space where the magneto used to reside. At least that's what I've been lead to understand, plus it's not very effective unless extra holes are drilled from the timing chest into the crank case. Plus the oil tank breather goes directly into the air filter, which in it's original state drips oil down on the air filter then the gearbox and you can imagine where it goes from there. Adding a catch bottle to the oil tank breather has stopped that issue. I know some with the central tank don't have this leakage problem, but it may be that they start their bike every day or their oil pump wet sumps a lot less than mine.
I've taken the path of least resistance and so far it seems to work. I'd love to put the Comstock breather on or block the timed breather and install a proper PCV in a place that may make a difference. But until I take the engine apart, it's working for me, that is, it's not leaking and the silicone on the valve covers is the least of the issues. At least I can re-use them, I just have to add a bit of silicone to the studs and associated washers when I take them off.
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Can anyone suggest a UK or EU source for the Yamaha XS valve?
Cheers, Aris
Cheers, Aris
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stockie2 said:
I have one and I can tell it has an effect - the oil cap sits still on the oil tank when its loose. Without the XS valve the oil cap would bounce up & down when loose.
I wish it worked better. But I still have a leak at the magneto oil seal (even with new seal). So I don't think there is negative pressure. The XS valve is connected to the timing cover so there should be negative pressure. When I made tests back in the 1980s using a one way EGR valve plumbed directly to the cases. I noticed that the valve would not function at high RPM - only near idle to low or mid RPM at best. It would not cycle fast enough at high RPM. I have heard from customers that big bore high compression racing engines can have so much blow and crank pressure that the PTO seal blows out and the one way valve (if used) is overwhelmed with oil flow. So has anyone actually seen negative pressure with a gauge at high RPM or under load?
N
nortonspeed
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Holland Norton Works supply the PCV breather valve ( http://www.hollandnortonworks.eu/?lang=EN&page=10 ).Kool_Biker said:
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