pcv valves and oil leaks
- Thread starter bigstu
- Start date
- Status
I know on Triumphs there is an issue with bottom and top end breathing and, as on Nortons, there is not a huge connecion area between the two so I think they should be treated separately.
The top end breathing issues tend to come from Valve leakage, and some Racers used to fill a small breather system which tapped off the rocker covers, using bongo fittings, and tapped straight ito the oil tank using 4mm solid pipe. This avoided blowing gaskets. Interesting about the amount of water one person sees from top end breather....
This I beleive to be less important than the issues with crank venting, where you have piston blowby and more importantly a huge difference in area between the crank air volume with the pistons at the top or at the bottom of their stroke.
Stuart.
The top end breathing issues tend to come from Valve leakage, and some Racers used to fill a small breather system which tapped off the rocker covers, using bongo fittings, and tapped straight ito the oil tank using 4mm solid pipe. This avoided blowing gaskets. Interesting about the amount of water one person sees from top end breather....
This I beleive to be less important than the issues with crank venting, where you have piston blowby and more importantly a huge difference in area between the crank air volume with the pistons at the top or at the bottom of their stroke.
Stuart.
"10 miles before the disc dissappeared"
Strange, I was told there is no disc in the ET valves, it is supposed to be a ball regulated valve. Confusing???
Was this many years ago? They might have changed the design by now?
My friend has used his for years with no problems (and I'm normally confident trusting his skills and experience, except he is not riding a Norton
)
Only maintenance is an annual clean that is an easy 5 minutes task to perform.
/Per
Strange, I was told there is no disc in the ET valves, it is supposed to be a ball regulated valve. Confusing???
Was this many years ago? They might have changed the design by now?
My friend has used his for years with no problems (and I'm normally confident trusting his skills and experience, except he is not riding a Norton
)Only maintenance is an annual clean that is an easy 5 minutes task to perform.
/Per
- Joined
- Apr 15, 2009
- Messages
- 11,527
Gene1 said:
I think it's "an English thing". You may not want to know the answer. Kind of like asking if there is really blood in blood pudding. You don't want to know the answer. :wink:
swooshdave said:
It's BLACK pudding, not blood pudding.
Don't know of anywhere that has blood pudding. The Germans have blood sausage (Blutwurst) and the British have Black pudding. Yes, it's made of blood with lumps of fat in it. It's delicious! What will REALLY disgust you is if you ever find out what goes into a hotdog :mrgreen:
I am guessing it's a BANJO fitting being referred to. 'Bongo' is probably a regional spelling of banjo :roll:
- Joined
- Nov 6, 2008
- Messages
- 502
well im english and never heard of a bongo fitting, maybe its a banjo or a barb who knows
- Joined
- Apr 15, 2009
- Messages
- 11,527
Corona850 said:
Everything but the oink.
swooshdave said:
There must be a reason be a reason why moving the valve works better, I can't figure it out though. There are some pretty remarkable gains to be had by getting the air out of the crankcase. One Commando racer said he was getting 5-6hp out of it. Appears to be a matter of pushing the air around. Formula One and NASCAR guys really work at it.
http://www.coloradonortonworks.com/cata ... e.asp#1713 This is cool, seems like it might be kinda wet, maybe.
- Joined
- Apr 15, 2009
- Messages
- 11,527
bpatton said:
From what I could tell the increase pressure in the Ducati crankcases reacted better when the valve was moved into the airbox. This seems to only work on race bikes which spend most of their time at high rpms. For street bikes the stock location works fine.
Hi blokes.. been a time between drinks...
I have mentioned my PVC set a number of times and give it the thumbs up for many years now.. As stated mine is a common GM (Holden - Australian) version sourced up from the local Auto accessory dept (Repco) for $20 ~ (Could be had easily from a wreckers too ~ if second hand does not bother you !)
The only criteria I have seen is that the valve should ideally placed as close as practical to the oil tank rather than the crankcase ~ And as previously stated the oil leak / misting was dramatically reduced !
I was going to install one on my current T150V Special Trident , but being a triple with 120 deg spacing of journals on the crank, the crankcase pressures are not the same deal as twin such as the Commando ~
As for Black sausage ~ :shock: :shock: :shock: About appealing as eating Brains ~ or Tripe ~ very sick puppies ` some !! ! :roll:
I have mentioned my PVC set a number of times and give it the thumbs up for many years now.. As stated mine is a common GM (Holden - Australian) version sourced up from the local Auto accessory dept (Repco) for $20 ~ (Could be had easily from a wreckers too ~ if second hand does not bother you !)
The only criteria I have seen is that the valve should ideally placed as close as practical to the oil tank rather than the crankcase ~ And as previously stated the oil leak / misting was dramatically reduced !
I was going to install one on my current T150V Special Trident , but being a triple with 120 deg spacing of journals on the crank, the crankcase pressures are not the same deal as twin such as the Commando ~
As for Black sausage ~ :shock: :shock: :shock: About appealing as eating Brains ~ or Tripe ~ very sick puppies ` some !! ! :roll:
OK guys,
Banjo fitting is the fitting I meant to type, its a bit like a yukealayli fitting but with 5 strings, not 4.
Black pudding is from Lancashire, not Yorkshire, where I reside. It is indeed congealed pigs blood with some gristle added for texture and added flavour....mmm....Tripe is the delicacy we tend to offer visitors to Yorkshire. This is the lining of a cows stomach and is served cold with a little vinegar. It looks a bit like whale blubber...
Stu.
Banjo fitting is the fitting I meant to type, its a bit like a yukealayli fitting but with 5 strings, not 4.
Black pudding is from Lancashire, not Yorkshire, where I reside. It is indeed congealed pigs blood with some gristle added for texture and added flavour....mmm....Tripe is the delicacy we tend to offer visitors to Yorkshire. This is the lining of a cows stomach and is served cold with a little vinegar. It looks a bit like whale blubber...
Stu.
Hi Guys,
For what it's worth I had the same trouble with oil leaks on my 1973 Mk 2 and it was also leaking from the tacho drive and slightly from the main seal in the chaincase. I ended up fitting a VW vacuum check valve
P/n 191 611 933 @ about $15 from the local VW spares store. This valve has the right size fittings for the breather hose and it is small enough to fit on top of the oil tank.
Since fitting the valve....all leaks have stopped. Hope this helps.
Tony
For what it's worth I had the same trouble with oil leaks on my 1973 Mk 2 and it was also leaking from the tacho drive and slightly from the main seal in the chaincase. I ended up fitting a VW vacuum check valve
P/n 191 611 933 @ about $15 from the local VW spares store. This valve has the right size fittings for the breather hose and it is small enough to fit on top of the oil tank.
Since fitting the valve....all leaks have stopped. Hope this helps.
Tony
- Joined
- Nov 27, 2006
- Messages
- 27
For what it's worth, I have had my 72 Commando for 25 years and it had started to develop oil weeps from a number of places. I went to my local wrecker and pulled a brake vacuum valve off an old Ford. I fitted it in the breather line to the oil tank (close to the oil tank). All the leaks have stopped. Unbelievable.
What's wrong with a new reed valve designed for a 650 cc twin cylinder motor with correct spigot size that sells for $16? I don't know if a vacuum brake check valve is quick enough at high rpms to open and close completely. I do know the MotorMite vacuum brake check valve became less effective after a few hundred miles.
Regardless what you use, isn't it great to no longer see those nasty oil leaks?
- Joined
- Aug 9, 2005
- Messages
- 218
I'm getting the dreaded oil leak through the primary side and am planning to order one of these Yamaha XS valves to mount near the oil tank. Does anybody have a photo of this valve mounted up, so that I can compare? (I also want to be sure I do not mount it backwards and cause my engine to explode with oil!). Thanks!
- Status
