The Sportster and Buell Motorcycle Forum MOTOSPORT  

Go Back   The Sportster and Buell Motorcycle Forum > SPORTSTER MOTORCYCLE ZONE > Sportster Motorcycle Era Specific and Model Specific > Ironhead Sportster Motorcycle Talk (1957-1985)
XLF Gallery XLF Classifieds XLF Blogs XLF Shout XLF Arcade XLF Disclaimer/Privacy Statement/Terms Of Use

Ironhead Sportster Motorcycle Talk (1957-1985) For all those that wanna talk about Ironhead Sportster Motorcycles

Members Birthdays
truckmen (57), Scooter Trash (52), K2RMX.ROB (50), Milazzo (48), benny04hd (34), Foxman (34), Chase1126 (23)
Get Lowered
Figure Machine
Speedway Instruments
S&S Cycle

Sky Smith Insurance
Reply
 
Share Thread Tools Display Modes
  #1  
Old 17th August 2009
FourCams's Avatar
FourCams FourCams is offline
Senior Chief Master Mechanic 1st Class
 
Join Date: Dec 2008
Location: Seattle
Posts: 1,295
Sportster/Buell Model: XLCH
Sportster/Buell Year: 1969
Sportster/Buell Model #2: XLCH
Sportster/Buell Year #2: 1972
Other Motorcycle Model: FXSTC
Other Motorcycle Year: 1996
Reputation: 5013
FourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really nice
Default Oil Transfer Valve

I've heard a lot of stuff about the mysterious oil transfer valve but couldn't find a thread that's dedicated specifically to it - so I'm starting one.
The transfer valve should be threaded into the case behind the primary cover and to the rear of the front primary chain (drive) sprocked.
It looks like this:

The oil transfer valve was used from 1957 - 1976. (OEM part number 25075-55.) It was discontinued in 1977.
I've been under the impression that it was put there to help keep the dry clutches from getting wet and it's designed so that oil will go from the primary to the engine if the primary oil level is too high. Does this sound right?
If the oil transfer valve is not blocked, oil from the primary can mix with oil in the engine. Some people plug the oil transfer valve and use ATF or other primary lubes in the primary/transmission. I'd be interested in seeing the different methods people have used to block off the oil transfer valve and what primary lube has been used after it's blocked. (Please don't turn this thread into an oil argument.)
If I understand correctly, the trans needs to be vented seperately if the oil transfer valve is blocked?
Anyhow, here it is.. the oil transfer valve thread.
Please share your oil transfer valve wisdom here.
__________________
♠ 1969 XLCH ♠ 1972 XLCH ♠ 1996 FXSTC ♠
Reply With Quote
  #2  
Old 17th August 2009
BuckIRyder BuckIRyder is offline
Custom Bike Builder
 
Join Date: Jun 2006
Posts: 2,463
Sportster/Buell Model: XLCH
Sportster/Buell Year: 1972
Other Motorcycle Model: Heritage Softail
Other Motorcycle Year: 1999
BuckIRyder has disabled reputation
Default

Blocked mine off ('72CH) years ago. No ill effects seen. Pulled it out and a friend put a spot of weld in it. Its just as effective to pull the guts out and tap the hole and locktite a screw in. I did it because my primary was mysteriously filling with oil. Turned out to be a failed sprocket shaft seal. My motor sprocket was cracked thru the land that the seal rode on and that cut up the seal face. My trans vents thru a very small hole in the primary fill/inspection plug. And yes the trans needs to be vented somehow. I use 20/50 motorcycle synthetic as lube.
Reply With Quote
  #3  
Old 17th August 2009
Ivan RoachCoach's Avatar
Ivan RoachCoach Ivan RoachCoach is offline
Banned
 
Join Date: Sep 2007
Location: Venetian Islands, Miami Beach
Posts: 3,923
Sportster/Buell Model: XLH/I.R.C. Special
Sportster/Buell Year: 1974
Ivan RoachCoach is just really niceIvan RoachCoach is just really niceIvan RoachCoach is just really niceIvan RoachCoach is just really niceIvan RoachCoach is just really niceIvan RoachCoach is just really niceIvan RoachCoach is just really niceIvan RoachCoach is just really niceIvan RoachCoach is just really niceIvan RoachCoach is just really niceIvan RoachCoach is just really nice
Default The El Cheapo way of doing it: Tap the hole in the valve...

...to either 8-32 or 10-32 thread-size (I forget which), thread in the appropriate screw slathered in red Loctite, and peen the screw head until it's distorted.

It'll never unscrew or back out of there --- EVER.
Reply With Quote
  #4  
Old 17th August 2009
superwarden's Avatar
superwarden superwarden is offline
Custom Bike Builder
 
Join Date: Dec 2006
Location: I really don't know :)
Posts: 2,477
Sportster/Buell Model: XLH
Sportster/Buell Year: 1968
Sportster/Buell Model #2: XLC
Sportster/Buell Year #2: 2003
Other Motorcycle Model: FXSTD
Other Motorcycle Year: 2003
Reputation: 11505
superwarden is a glorious beacon of lightsuperwarden is a glorious beacon of lightsuperwarden is a glorious beacon of lightsuperwarden is a glorious beacon of lightsuperwarden is a glorious beacon of lightsuperwarden is a glorious beacon of lightsuperwarden is a glorious beacon of lightsuperwarden is a glorious beacon of lightsuperwarden is a glorious beacon of lightsuperwarden is a glorious beacon of lightsuperwarden is a glorious beacon of light
Default

Yep get rid of it if you like. Not much oil is ever "transferred" through it.
__________________
Any date that is not on your tombstone is considered a lucky day.
Reply With Quote
  #5  
Old 17th August 2009
RRB RRB is offline
Senior Chief Know It All
 
Join Date: Jul 2006
Posts: 899
Sportster/Buell Model: XLH
Sportster/Buell Year: 1966
Reputation: 441
RRB is on a distinguished roadRRB is on a distinguished roadRRB is on a distinguished roadRRB is on a distinguished roadRRB is on a distinguished road
Default

Quote:
Originally Posted by FourCams View Post
I've been under the impression that it was put there to help keep the dry clutches from getting wet and it's designed so that oil will go from the primary to the engine if the primary oil level is too high. Does this sound right?
Doesn't sound right to me. I don't think it had anything to do with the clutch, as the plates were isolated behind the derby cover and "should" be impervious to the oil in the primary/trans. I don't think the intention of the valve was to keep the primary oil at a certain volume. I think the valve had more to do with crankcase pressure than with oil levels.
Quote:
Originally Posted by FourCams View Post

If the oil transfer valve is not blocked, oil from the primary can mix with oil in the engine.
The problem is usually not oil from the primary migrating from the primary to the crankcase, but the other way around, at least in my experience.

Your thread is a good idea, though. I'm interested in what others have to say, too.
Reply With Quote
Know Thy Hog

  #6  
Old 18th August 2009
MDT's Avatar
MDT MDT is offline
Custom Bike Builder
 
Join Date: Jul 2006
Location: Northern Colorado
Posts: 2,242
Sportster/Buell Model: XLCH
Sportster/Buell Year: 61
Other Motorcycle Model: Superglide
Other Motorcycle Year: 74
Reputation: 22951
MDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to all
Default

I just posted on another thread, it's a crankcase "breather". If oil splashes over to the primary side it is incidental. If you use the same oil in your tranny and your engine, it's not a problem. If you don't you should probably plug it. I don't plug mine.
__________________
When you sit on something, you built from parts;
You're sitting on top of the world.
Reply With Quote
  #7  
Old 18th August 2009
FourCams's Avatar
FourCams FourCams is offline
Senior Chief Master Mechanic 1st Class
 
Join Date: Dec 2008
Location: Seattle
Posts: 1,295
Sportster/Buell Model: XLCH
Sportster/Buell Year: 1969
Sportster/Buell Model #2: XLCH
Sportster/Buell Year #2: 1972
Other Motorcycle Model: FXSTC
Other Motorcycle Year: 1996
Reputation: 5013
FourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really nice
Default

So... what exactly is the purpose of the oil transfer valve?
The primary vents through the oil filler plug doesn't it?
I'm reasonably certain (but not positive) that if the primary is overfilled the oil will go into the engine throught the transfer valve. I don't think it's supposed to allow oil from the engine into the primary though.
Reply With Quote
  #8  
Old 18th August 2009
MDT's Avatar
MDT MDT is offline
Custom Bike Builder
 
Join Date: Jul 2006
Location: Northern Colorado
Posts: 2,242
Sportster/Buell Model: XLCH
Sportster/Buell Year: 61
Other Motorcycle Model: Superglide
Other Motorcycle Year: 74
Reputation: 22951
MDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to allMDT is a name known to all
Default

The pupose is to vent the pressure from the engine crankcase created by your pistons as they go up and down. As Mick stated in the other thread, oil transfer valve is not the proper term for this item. It was never intended to prevent too much oil in your primary.
Reply With Quote
  #9  
Old 18th August 2009
FourCams's Avatar
FourCams FourCams is offline
Senior Chief Master Mechanic 1st Class
 
Join Date: Dec 2008
Location: Seattle
Posts: 1,295
Sportster/Buell Model: XLCH
Sportster/Buell Year: 1969
Sportster/Buell Model #2: XLCH
Sportster/Buell Year #2: 1972
Other Motorcycle Model: FXSTC
Other Motorcycle Year: 1996
Reputation: 5013
FourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really niceFourCams is just really nice
Default

Quote:
Originally Posted by MDT View Post
The pupose is to vent the pressure from the engine crankcase created by your pistons as they go up and down. As Mick stated in the other thread, oil transfer valve is not the proper term for this item. It was never intended to prevent too much oil in your primary.
Why would the crankcase vent into the primary? The crankcase has a breather on the oil pump and it vents through the cam chest doesn't it?

Are sure you're not talking about the "foo foo" valve?

If it's not the proper term, why would J&P, V-Twin, this forum, and every other Ironhead forum I've seen over the past 15 years refer to it as an oil transfer valve?
And why would the people who have plugged it not be having problems with engine seals if after they blocked it they vented the transmission and not the engine?
It makes more sense to me that it would vent from the primary into the crankcase - especially since there's a vacuum in the engine when the piston goes up and the crankcase breather is on the opposite side of the engine.

(I'm really confused)
Reply With Quote
  #10  
Old 18th August 2009
Hopper's Avatar
Hopper Hopper is offline
Senior Master Custom Bike Builder
 
Join Date: Dec 2007
Location: Australia
Posts: 8,567
Sportster/Buell Model: XLCH 1000
Sportster/Buell Year: 1977
Sportster/Buell Model #2: 75 motor in Norton frame.
Other Motorcycle Model: 42WLA 45, Harton, Narley
Other Motorcycle Year: 1942
Reputation: 61853
Hopper is a splendid one to beholdHopper is a splendid one to beholdHopper is a splendid one to beholdHopper is a splendid one to beholdHopper is a splendid one to beholdHopper is a splendid one to beholdHopper is a splendid one to beholdHopper is a splendid one to beholdHopper is a splendid one to beholdHopper is a splendid one to beholdHopper is a splendid one to behold
Default

+1 on that. There is a whole crankcase breather system timed on the oil pump and venting out past the generator drive. That oil transfer valve, whatever its purpose, is not to control crankcase pressure. No way is the crankcase breathing into the primary, which then breathes to atmosphere through a pin hole in the filler cap.

Which way is valve set up to flow? If someone has a set of cases around, can they see if the valve is set to allow flow from the primary into the crankcases or vice versa?

I always assumed it allowed oil to flow from the primary back into the crankcase if the sprocket shaft seal was leaking.
__________________
In theory there is no difference between theory and practice. In practice there is.
Reply With Quote
Know Thy Hog

Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


Custom Search

All times are GMT +1. The time now is 01:58.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
XL Forum - Linson Media LLC