ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 05-02-2015, 01:38 AM   #1
Phreaky Phil OP
Beastly Adventurer
 
Joined: Mar 2006
Location: NEW ZEALAND
Oddometer: 1,870
A question for the engine Guru's

Years ago I was having problems with oil consumption and bad cylinder carboning up on my GS. We finally diagnosed the problem being valve guides.
However they had been replaced and were measured 3 times to be right in the middle of BMW specs. Advice from Paul Rooney put me on to K Liners, a valve guide insert with minimal, I think around 1 thou clearance.
My question is, has anyone use a valve guide seal, can it be done and if not, why ?
Looking forward to your replies.
Phil
__________________
And then one day you find ten years has got behind you
No one told you when to run, you missed the starting gun.

Pink Floyd
Phreaky Phil is offline   Reply With Quote
Old 05-02-2015, 02:16 AM   #2
Voltaire
Bored Of The Rings
 
Voltaire's Avatar
 
Joined: Jun 2011
Location: Auckland,New Zealand
Oddometer: 1,656
Not a Guru, but have had K liners fitted to racebike as Maxheadroom was in a previous life an engine reconditioner.
Would you only need seals if the top of valve was immersed in oil like a vertical motor?
BMW's smoke sometimes on start up, I thought that was due to the valve cover oil being drawn into the guides....or is it the oil that sits in the bore if the engine is stopped at the bottom of the piston travel?

---------------------------

I've got a bike you can ride it if you like its not a good bike....and some rambling about a mouse called Gerald.
__________________
Link to Classic BMW Racer Project.
Noobs guide to racing.
http://www.advrider.com/forums/showthread.php?t=790873
Saigon to Hanoi two up on a Honda 150
http://advrider.com/forums/showthrea...1009571&page=2

Voltaire screwed with this post 05-02-2015 at 02:59 AM Reason: Pink Floyd referance...sort of
Voltaire is offline   Reply With Quote
Old 05-02-2015, 02:39 AM   #3
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 9,820
Also not a Guru.

I'm confused by your question. You start off with this being a former problem but now you have the same problem again?

I think the valve guide liners are just a way to avoid putting in new valve guides. Either new guides or the inserts can be finished to which ever dimension you want.

If you use inserts is it the correct material to go with whatever valves you have?

Have heard of using valve guide seals and heard they work. Some of the "Guru's" on the Airlist will object but I don't know the reason why. I think it may be that new valve guides should work so if you do proper guides, seals are not needed.

You may even get objections here but generally this place is less conservative that the Airlist.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 05-02-2015, 03:01 AM   #4
Phreaky Phil OP
Beastly Adventurer
 
Joined: Mar 2006
Location: NEW ZEALAND
Oddometer: 1,870
Quote:
Originally Posted by Voltaire View Post
Not a Guru, but have had K liners fitted to racebike as Maxheadroom was in a previous life an engine reconditioner.
Would you only need seals if the top of valve was immersed in oil like a vertical motor?
BMW's smoke sometimes on start up, I thought that was due to the valve cover oil being drawn into the guides....or is it the oil that sits in the bore if the engine is stopped at the bottom of the piston travel?
I understood smoke on startup was oil in the bores finding its way past the rings. Mine only does it on rare occasions, bloody embarrassing clouds of smoke
Never happens if bike on centre stand.
__________________
And then one day you find ten years has got behind you
No one told you when to run, you missed the starting gun.

Pink Floyd
Phreaky Phil is offline   Reply With Quote
Old 05-02-2015, 03:06 AM   #5
Phreaky Phil OP
Beastly Adventurer
 
Joined: Mar 2006
Location: NEW ZEALAND
Oddometer: 1,870
Quote:
Originally Posted by disston View Post
Also not a Guru.

I'm confused by your question. You start off with this being a former problem but now you have the same problem again?

I think the valve guide liners are just a way to avoid putting in new valve guides. Either new guides or the inserts can be finished to which ever dimension you want.

If you use inserts is it the correct material to go with whatever valves you have?

Have heard of using valve guide seals and heard they work. Some of the "Guru's" on the Airlist will object but I don't know the reason why. I think it may be that new valve guides should work so if you do proper guides, seals are not needed.

You may even get objections here but generally this place is less conservative that the Airlist.
I'm not sure if the standard guide material can run as closer tolerances as a K liner which has very fine grooves in its bore for lubrication.
You can't have seen my other thread in Airheads. New bike time
__________________
And then one day you find ten years has got behind you
No one told you when to run, you missed the starting gun.

Pink Floyd
Phreaky Phil is offline   Reply With Quote
Old 05-02-2015, 03:27 AM   #6
motu
Loose Pre Unit
 
motu's Avatar
 
Joined: Dec 2001
Location: New Zealand
Oddometer: 4,569
OHC engines use valve seals because of the huge amount of oil up there. Pushrod engines use an umbrella seal, some an O ring below the keepers. That's in normal vertical engines, a horizontal engine may be different. K Liners were for Fords which didn't have valve guides, just holes in the head for the valves, you got valves with thicker stems if the guides were worn. But K Liners are good anyway, replacing guides takes longer and can damage an alloy head.
motu is online now   Reply With Quote
Old 05-02-2015, 09:20 AM   #7
R100RTurbo
Perky Sleeper
 
R100RTurbo's Avatar
 
Joined: May 2014
Location: Abbotsford, BC Canada
Oddometer: 229
Quote:
Originally Posted by Phreaky Phil View Post
Years ago I was having problems with oil consumption and bad cylinder carboning up on my GS. We finally diagnosed the problem being valve guides.
However they had been replaced and were measured 3 times to be right in the middle of BMW specs. Advice from Paul Rooney put me on to K Liners, a valve guide insert with minimal, I think around 1 thou clearance.
My question is, has anyone use a valve guide seal, can it be done and if not, why ?
Looking forward to your replies.
Phil
In answer to your question, yes have added stem seals to the intake guides and found complete reduction of oil consumption where stem to guide clearance was within spec but random "blue trailing clouds" and start up smoke had been noted. Adding to the exhaust will not tend to be benificial.
The obvious risk might be accelerated wear but I wasn't able to witness that either.
FelPro #SS70816
__________________
Project link - http://advrider.com/forums/showthrea...ght=R100RTurbo
R100RTurbo is offline   Reply With Quote
Old 05-02-2015, 11:07 AM   #8
Beemeup
1978 R100/7
 
Beemeup's Avatar
 
Joined: Sep 2014
Location: Washington State
Oddometer: 367
Quote:
Originally Posted by Phreaky Phil View Post
I understood smoke on startup was oil in the bores finding its way past the rings. Mine only does it on rare occasions, bloody embarrassing clouds of smoke
Never happens if bike on centre stand.
Sounds normal!
Beemeup is offline   Reply With Quote
Old 05-02-2015, 11:10 PM   #9
Phreaky Phil OP
Beastly Adventurer
 
Joined: Mar 2006
Location: NEW ZEALAND
Oddometer: 1,870
Quote:
Originally Posted by R100RTurbo View Post
In answer to your question, yes have added stem seals to the intake guides and found complete reduction of oil consumption where stem to guide clearance was within spec but random "blue trailing clouds" and start up smoke had been noted. Adding to the exhaust will not tend to be benificial.
The obvious risk might be accelerated wear but I wasn't able to witness that either.
FelPro #SS70816
thanks for that. Just what I was hoping to hear. I assume a grove to locate the seal must be machined in the valve guide ?
__________________
And then one day you find ten years has got behind you
No one told you when to run, you missed the starting gun.

Pink Floyd
Phreaky Phil is offline   Reply With Quote
Old 05-03-2015, 01:32 AM   #10
motu
Loose Pre Unit
 
motu's Avatar
 
Joined: Dec 2001
Location: New Zealand
Oddometer: 4,569
Modern ohc valve seals are a tight fit on the guide, you'd have to find some to fit close enough. But there were some earlier ones (say 12R Toyota) that just fitted over the guide and were held down by the inner spring.

I think I mean 18R, the 12R was a pushrod engine.

motu screwed with this post 05-03-2015 at 04:32 AM
motu is online now   Reply With Quote
Old 05-03-2015, 02:34 AM   #11
innathyzit
AKA Woodman
 
innathyzit's Avatar
 
Joined: Dec 2008
Location: Nelson NZ
Oddometer: 1,159
Quote:
Originally Posted by Phreaky Phil View Post
thanks for that. Just what I was hoping to hear. I assume a grove to locate the seal must be machined in the valve guide ?

Modern valve guide seals are a press fit. We had a mandrel set for fitting the seals so they lined up perfectly on the valve stem. This is in OHC engines that really need seals unlike pushrod motors where they don't do much if anything at all.
innathyzit is online now   Reply With Quote
Old 05-03-2015, 08:06 AM   #12
Bill Harris
Confirmed Curmudgeon
 
Bill Harris's Avatar
 
Joined: Sep 2008
Location: backwoods Alabama
Oddometer: 8,015
I like the puff of smoke at startup. Rather reminiscent of the Baron von Richthofen firing up a radial engine in his biplane.



:)

--Bill
__________________
'73 R60/5 Toaster
Luddite. Not just a philosophy, a way of life...
Bill Harris is offline   Reply With Quote
Old 05-03-2015, 08:11 AM   #13
R100RTurbo
Perky Sleeper
 
R100RTurbo's Avatar
 
Joined: May 2014
Location: Abbotsford, BC Canada
Oddometer: 229
Wicked

Quote:
Originally Posted by Phreaky Phil View Post
thanks for that. Just what I was hoping to hear. I assume a grove to locate the seal must be machined in the valve guide ?
That item I listed is the part to use (FelPro #SS70816) and for the 8mm valve stems with 14mm guide OD - no machining required. You can install without head removal too if that turns your crank
__________________
Project link - http://advrider.com/forums/showthrea...ght=R100RTurbo
R100RTurbo is offline   Reply With Quote
Old 05-03-2015, 08:12 AM   #14
Renner
rockin' the toaster
 
Renner's Avatar
 
Joined: Jul 2007
Location: sunny SoCal
Oddometer: 2,258
Quote:
Originally Posted by disston
Some of the "Guru's" on the Airlist will object but I don't know the reason why. I think it may be that new valve guides should work so if you do proper guides, seals are not needed.
The objection being (as I recall) that to fit a seal the guide is shortened, and that shortening the guide's length would promote oil transfer at the stem, making the stem seal necessary.

And as disston writes, good guides don't need them.

My /5 has stem seals and I have no complaints about them.

I see above ^ that seal can be installed without altering the guide's length, so the objection I'd read on the Airlist apparently doesn't apply to those seals.
__________________
"If you want to fix it with a rock, you have to stick to stone-age technology" -Anton
"...solving the latest crisis that is preventing my Airhead from taking me to the bar." -Beater-

Renner screwed with this post 05-03-2015 at 08:20 AM
Renner is offline   Reply With Quote
Old 05-03-2015, 08:18 AM   #15
R100RTurbo
Perky Sleeper
 
R100RTurbo's Avatar
 
Joined: May 2014
Location: Abbotsford, BC Canada
Oddometer: 229
Quote:
Originally Posted by Renner View Post
The objection being (as I recall) that to fit a seal the guide is shortened, and that shortening the guide's length would promote oil transfer at the stem, making the stem seal necessary.

And as disston writes, good guides don't need them.

My /5 has stem seals and I have no complaints about them.
For 8mm stem arrangement no guide shortening required on stock lift cam.
__________________
Project link - http://advrider.com/forums/showthrea...ght=R100RTurbo
R100RTurbo is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
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 On

Forum Jump


Times are GMT -7.   It's 11:29 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2015