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 03-14-2013, 06:06 PM   #46
khale OP
ride dirty
 
khale's Avatar
 
Joined: Oct 2009
Location: Atlanta, GA
Oddometer: 550
Quote:
Originally Posted by disston View Post

What SS says about the ring grooves seems to be the key to deciding if you need new pistons. Then you may get over sized pistons and better fitting rings to boot. But if the ring grooves are serviceable then keep the ones you got.
Ring grooves on pistons are fine and literally look brand new. I'll keep the rings, button her back up and do a leak down and compression check (should have done this before I started the tear down)
__________________
2013 BMW R1200 GSW | 1972 BMW R75/5 toaster | 2011 Husky TE310
"4 wheels move the body, 2 wheels move the soul"
khale is offline   Reply With Quote
Old 03-14-2013, 06:44 PM   #47
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 7,580
Quote:
Originally Posted by khale View Post
top ring, spec is .30 - .45mm; mine is at least .55mm or higher
middle ring, spec is .30 - .45mm; mine is at least .55mm or higher
bottom ring (oil ring), spec is .25 - .40mm; mine is at least .50mm or higher

What I'm getting at is all my rings are out of spec by .10mm - .15mm at least. Some folks here are saying take the out of spec philosophy with a grain of salt, and I need clarification on that, and what 'feel' is.
That's about par in my experience. I have measured a number of brand new later setups. They were always out of spec too wide. Most all of BMW's engine specs are way tighter than they actually come form the factory. They most likely had the same spec brand new.

The guides? You need a spring compressor to look at them anyway. You are not set up to do this right experience wise or tool wise I believe. There is no sense in taking the top end off regarding oil usage and not taking the valves out to check the guides.
supershaft is offline   Reply With Quote
Old 03-14-2013, 06:49 PM   #48
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 7,580
Quote:
Originally Posted by khale View Post
Ring grooves on pistons are fine and literally look brand new. I'll keep the rings, button her back up and do a leak down and compression check (should have done this before I started the tear down)
Now your making sense. I always do most of my diagnostics BEFORE I take the engine apart. It really cuts out a lot of guessing! A leak down in itself takes some experience. 80% of it is NOT about the numbers but whether or not your valves are leaking. Ascertaining that takes experience.

With the knowledge those diagnostic tests give you, looking at the insides often answers questions instead of raising them.
supershaft is offline   Reply With Quote
Old 03-14-2013, 07:08 PM   #49
khale OP
ride dirty
 
khale's Avatar
 
Joined: Oct 2009
Location: Atlanta, GA
Oddometer: 550
Quote:
Originally Posted by supershaft View Post
That's about par in my experience. I have measured a number of brand new later setups. They were always out of spec too wide. Most all of BMW's engine specs are way tighter than they actually come form the factory. They most likely had the same spec brand new.

The guides? You need a spring compressor to look at them anyway. You are not set up to do this right experience wise or tool wise I believe. There is no sense in taking the top end off regarding oil usage and not taking the valves out to check the guides.
No need to worry about valves, guides, springs. I had my heads completey rebuilt, new valves, new exhaust seats (5 angle cut), guides and springs :)
__________________
2013 BMW R1200 GSW | 1972 BMW R75/5 toaster | 2011 Husky TE310
"4 wheels move the body, 2 wheels move the soul"
khale is offline   Reply With Quote
Old 03-14-2013, 08:09 PM   #50
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,451
Quote:
Originally Posted by khale View Post
Ha, not the direction, I'm not that dense. I'm talking about which cylinder goes on which side of the engine block.
Put the right one on the right and the left on on the left?

The jugs are the same, can go on either side, Put the grade stamp up. The wear on the bore is on the upper and lower surfaces, that is when they get oval the axis of the oval is vertical.
Plaka is offline   Reply With Quote
Old 03-14-2013, 08:27 PM   #51
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,451
Quote:
Originally Posted by khale View Post
Care to elaborate? The rings are out of spec per the manual. How do people determine when it's time to replace rings if we aren't going by a guide, such a Hayne's?
How about just not replacing them? if they have 90-100K on them, and the gap is way out but the cylinder is good, and the ring Thickness is good, then replace them based on the mileage. The fatigue. if the thickness is bad (too thin), replace them. If the milage isn't great, the thicknes is good but the gap in a good cylinder is too eyebrows fat, hell, run the damn things. Go ahead, pull out an eyebrow hair and look at it.

if the gap is tight, file them to spec.

New pistons get new rings. Usually comes with them and the BMW pistons I have bought have them installed to boot.I'll tell you what the gaps are in a week when the paint drys on the jugs and I put the pistons in.
Plaka is offline   Reply With Quote
Old 03-14-2013, 08:46 PM   #52
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 7,336
It is true that the cylinders can go on either side. But if you marked the pistons and got them separated from the cylinders you may want to figure out which cylinders go to which pistons by determining which side either cylinder goes to.

Quote:
the cylinders were exposed to the grit and abrasive substances kicked up from the road on their leading edge. If you look at the push rod tubes you will see one edge shows this collection of abuse from the direction of travel.
This is the only way I know to tell which cylinder goes to which side. If you face the abraded sides of the push rod tubes forward they will be on the side they came from.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, privatejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is online now   Reply With Quote
Old 03-14-2013, 09:00 PM   #53
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 7,580
Quote:
Originally Posted by disston View Post
It is true that the cylinders can go on either side. But if you marked the pistons and got them separated from the cylinders you may want to figure out which cylinders go to which pistons by determining which side either cylinder goes to.



This is the only way I know to tell which cylinder goes to which side. If you face the abraded sides of the push rod tubes forward they will be on the side they came from.
+1 The dirty side is the front.
supershaft is offline   Reply With Quote
Old 03-15-2013, 07:43 AM   #54
khale OP
ride dirty
 
khale's Avatar
 
Joined: Oct 2009
Location: Atlanta, GA
Oddometer: 550
Quote:
Originally Posted by disston View Post
It is true that the cylinders can go on either side. But if you marked the pistons and got them separated from the cylinders you may want to figure out which cylinders go to which pistons by determining which side either cylinder goes to.



This is the only way I know to tell which cylinder goes to which side. If you face the abraded sides of the push rod tubes forward they will be on the side they came from.
I marked down a number for each piston, the left piston had an 18 marked on it and the right piston had a 16 marked on it, so I know which side the pistons go on. Regarding the abrasion on the push rod seals (and slight road grit/gravel damage on the cylinder barrels), it's now easy for me to see which cylinder barrel goes for which side of the motor.
Thanks for everyone's help.
__________________
2013 BMW R1200 GSW | 1972 BMW R75/5 toaster | 2011 Husky TE310
"4 wheels move the body, 2 wheels move the soul"
khale is offline   Reply With Quote
Old 03-15-2013, 07:45 AM   #55
khale OP
ride dirty
 
khale's Avatar
 
Joined: Oct 2009
Location: Atlanta, GA
Oddometer: 550
Quote:
Originally Posted by supershaft View Post
+1 The dirty side is the front.
That's a good way to put it, thanks SS
__________________
2013 BMW R1200 GSW | 1972 BMW R75/5 toaster | 2011 Husky TE310
"4 wheels move the body, 2 wheels move the soul"
khale is offline   Reply With Quote
Old 03-15-2013, 08:07 AM   #56
khale OP
ride dirty
 
khale's Avatar
 
Joined: Oct 2009
Location: Atlanta, GA
Oddometer: 550
Anyone had any luck with Permatex nickel based anti-seize for the header nuts? I've read that you want a copper/nickel base anti-seize to withstand the high temps.
__________________
2013 BMW R1200 GSW | 1972 BMW R75/5 toaster | 2011 Husky TE310
"4 wheels move the body, 2 wheels move the soul"
khale is offline   Reply With Quote
Old 03-15-2013, 08:23 AM   #57
Kt-88
I like everything.
 
Kt-88's Avatar
 
Joined: Sep 2012
Location: SLC area, Utah
Oddometer: 414
Quote:
Originally Posted by khale View Post
Anyone had any luck with Permatex nickel based anti-seize for the header nuts? I've read that you want a copper/nickel base anti-seize to withstand the high temps.
That's what I'm using. My nuts come off easily.


Lol.
Kt-88 is offline   Reply With Quote
Old 03-15-2013, 09:05 AM   #58
SOLO LOBO
airhead or nothing
 
SOLO LOBO's Avatar
 
Joined: Mar 2004
Location: Shoreline, WA
Oddometer: 8,336
I've used the nickel as well... but always unthread my nuts (lol) at least once a year.

I've switched to the copper stuff, but man it is spendy!
__________________
"punkrocks what it's all about" - J. Strummer



Quote:
Originally Posted by Stagehand
your bike is suitably dirty. Well done.
SOLO LOBO is offline   Reply With Quote
Old 03-15-2013, 09:36 AM   #59
khale OP
ride dirty
 
khale's Avatar
 
Joined: Oct 2009
Location: Atlanta, GA
Oddometer: 550
Do any of you have advice on a good compression tester kit? I'm eyeballing this one right now:
http://www.amazon.com/gp/customer-me...x=0&isremote=0
__________________
2013 BMW R1200 GSW | 1972 BMW R75/5 toaster | 2011 Husky TE310
"4 wheels move the body, 2 wheels move the soul"
khale is offline   Reply With Quote
Old 03-15-2013, 09:41 AM   #60
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 7,336
I don't have a leak down kit yet but have looked at them. The OTC brand is almost always my first choice for quality and price. Price on this has come down I think in the last year.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, privatejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is online now   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 05:48 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014