ADVrider

Go Back   ADVrider > Gear > The Garage
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 03-10-2013, 09:29 AM   #1
mtn500 OP
bush jumper
 
mtn500's Avatar
 
Joined: Sep 2006
Location: Floyd, VA, Edenton, NC
Oddometer: 301
Replacing cylinder head exhaust studs

Does anyone have any experience with installing new exhaust studs into a cylinder head?
My question specifically is, how much resistance is normal given the threads are most likely interference threads?
I'm trying to insert new studs into a cylinder head from a 1979 Honda XL500s.
The studs start to thread in but then seem to "not fit", for lack of better terms; I've verified that I have the correct parts.
This resistance may be normal but I would like to verify so that I continue and stop worrying about stripping the threads in the cylinder head.
Link to original post if anyone is interested in more details (probably not the best way but I just copied and pasted address): http://www.advrider.com/forums/showt...=390135&page=5

Any insights or suggestions would be greatly appreciated.

Thanks
__________________
certs and destroy

If... the machine of government... is of such a nature that it requires you to be the agent of injustice to another, then, I say, break the law.

When any government, or any church for that matter, undertakes to say to its subjects, "This you may not read, this you may not see, this you are forbidden to know", the end result is tyranny and oppression no matter how holy the motives.


mtn500 is offline   Reply With Quote
Old 03-10-2013, 09:49 AM   #2
Claytonroy
Gnarly Adventurer
 
Joined: Jan 2006
Location: Oregon
Oddometer: 287
Have you tried tightening them with an electric impact driver?

I think the vibration would help greatly and you would not risk over torquing them.
Claytonroy is offline   Reply With Quote
Old 03-10-2013, 09:53 AM   #3
D.T.
One wheel wonder...
 
D.T.'s Avatar
 
Joined: Aug 2004
Location: Moneyapolis, MN
Oddometer: 9,437
Wink

Clean up the threads with a bottoming tap.
__________________
Quote:
Originally posted by burgerking So?
Holland is about the most expensive country in Europe when it comes to bikes and fuel..Stop whining and go riding It's just money and you only live once...
D.T. is online now   Reply With Quote
Old 03-10-2013, 10:33 AM   #4
usgser
Beastly Adventurer
 
Joined: Nov 2005
Location: Westside WA
Oddometer: 1,962
Quote:
Originally Posted by D.T. View Post
Clean up the threads with a bottoming tap.
x2
You're going to have old dried residual thread locker in the holes that needs to be thoroughly cleaned out.
usgser is offline   Reply With Quote
Old 03-10-2013, 10:39 AM   #5
troidus
Beastly Adventurer
 
Joined: Sep 2010
Oddometer: 11,735
Verify the pitch with a thread gauge and the diameter with a ball gauge before you bugger things up. Just because you've verified a part number doesn't mean what you're holding is that part. And if it is indeed supposed to be an interference fit, check with your local industrial supply for some liquid nitrogen and freeze the studs before trying to insert them. Heating the head may help, too.
troidus is offline   Reply With Quote
Old 03-10-2013, 11:07 AM   #6
It'sNotTheBike
Banned
 
Joined: Jul 2011
Oddometer: 704
Quote:
Originally Posted by D.T. View Post
Clean up the threads with a bottoming tap.

+1 on using a tap rather than forcing the studs to thread
in.



Using an impact is NOT a good idea !!! Don't do that !!!!


The guy above who said you need to make sure the thread size is correct
is giving you good advice. Try to thread the original exhaust nuts
onto the new studs. Those original nuts should thread onto the new
studs easily. If they do not thread on easily you need to look more closely
at the new studs which may indeed be the wrong thread size, or maybe they
are fine thread when they should be coarse thread, etc.


Use light cutting oil when you use the tap, and then make sure
the holes and threads are super clean and don't have a pool
of oil in the bottom of the hole before you install the studs. Brake
cleaning spray and compressed air would be a good way to make
sure things are clean before installing the studs.


.

It'sNotTheBike screwed with this post 03-10-2013 at 11:15 AM
It'sNotTheBike is offline   Reply With Quote
Old 03-10-2013, 12:38 PM   #7
mtn500 OP
bush jumper
 
mtn500's Avatar
 
Joined: Sep 2006
Location: Floyd, VA, Edenton, NC
Oddometer: 301
Thanks for the input.

I have ran a tap through the cylinder head threads, but I will do again to make sure everything is squeaky clean.

I will see what I can do about verifying the pitch and diameter with a thread gauge and ball gauge; currently all I have at my disposal is a tap and die set and a set of vernier calipers.

I don't have an impact driver at my disposal so that option is ruled out.

Unfortunately, I do not have the original exhaust studs as I purchased this engine as a spare so I could fix my burnt up head. The engine had been partially rebuilt and did not have the exhaust studs when i received it. My original head still has it's studs but I don't want to remove them as I plan on sending the head off to CA and having bearings installed so I can have a back-up.

As far as liquid N2, I contemplated freezing the head and the studs, but I wanted some practical advice before I carried on with the interference fit theory. Wouldn't heating the head expand it, resulting in slightly smaller diameter stud holes?

Thanks much for everyone input thus far.
__________________
certs and destroy

If... the machine of government... is of such a nature that it requires you to be the agent of injustice to another, then, I say, break the law.

When any government, or any church for that matter, undertakes to say to its subjects, "This you may not read, this you may not see, this you are forbidden to know", the end result is tyranny and oppression no matter how holy the motives.


mtn500 is offline   Reply With Quote
Old 03-10-2013, 12:49 PM   #8
griffo1962
Beastly Adventurer
 
griffo1962's Avatar
 
Joined: Oct 2006
Location: Carrara, Qld, Australia
Oddometer: 1,383
Quote:
Originally Posted by mtn500 View Post

As far as liquid N2, I contemplated freezing the head and the studs, but I wanted some practical advice before I carried on with the interference fit theory. Wouldn't heating the head expand it, resulting in slightly smaller diameter stud holes

Nope, it's counter intuitive I know but heating the head actually increases the size of the hole....
griffo1962 is offline   Reply With Quote
Old 03-10-2013, 12:59 PM   #9
Stan_R80/7
Beastly Gnarly
 
Stan_R80/7's Avatar
 
Joined: May 2012
Location: VA
Oddometer: 1,058
Heat the head and freeze the studs. The holes will expand in the head at higher temperature and the studs will shrink with lower temperature. Double check the thread diameter and pitch before assembly. Good luck!
Stan_R80/7 is offline   Reply With Quote
Old 03-11-2013, 02:29 PM   #10
emti
Gnarly Adventurer
 
Joined: Aug 2010
Location: northern n.y.
Oddometer: 221
Are both ends of the stud the same pitch/length? Are they bottoming out in the hole? emti
emti is offline   Reply With Quote
Old 03-11-2013, 03:34 PM   #11
mtn500 OP
bush jumper
 
mtn500's Avatar
 
Joined: Sep 2006
Location: Floyd, VA, Edenton, NC
Oddometer: 301
Quote:
Originally Posted by emti View Post
Are both ends of the stud the same pitch/length? Are they bottoming out in the hole? emti
emti, the pitch diameter is different; the shorter thread length has a larger diameter than the longer length. The longer length will bottom out in the cylinder head but the short one will not; it gets really tight when the threads are about half way into the head.
__________________
certs and destroy

If... the machine of government... is of such a nature that it requires you to be the agent of injustice to another, then, I say, break the law.

When any government, or any church for that matter, undertakes to say to its subjects, "This you may not read, this you may not see, this you are forbidden to know", the end result is tyranny and oppression no matter how holy the motives.


mtn500 is offline   Reply With Quote
Old 03-12-2013, 05:45 AM   #12
anotherguy
Beastly Adventurer
 
anotherguy's Avatar
 
Joined: Jun 2009
Location: the hills
Oddometer: 5,915
Cleaning threads with taps/dies is a no-no. You don't want to remove metal only clean the threads. Use a proper thread chasing tool.

The stud threads that install into the head are likely a class of thread that is an interference fit. That is they are larger than a common bolt and go into the hole tight to allow the nut to be removed w/o taking the stud with it and to allow for the heat of the part in normal operating conditions i.e. HOT. Tread lightly here or face continuing problems.

I have a stud installation tool for those jobs. Makes it a lot easier.
__________________
A lie has no feet......it can't stand alone.............
Jason Newsted
anotherguy is offline   Reply With Quote
Old 03-14-2013, 09:51 AM   #13
bomber60015
Anatomically Correct
 
bomber60015's Avatar
 
Joined: Sep 2008
Location: Chicago-ish
Oddometer: 8,144
Quote:
Originally Posted by anotherguy View Post
Cleaning threads with taps/dies is a no-no. You don't want to remove metal only clean the threads. Use a proper thread chasing tool.

The stud threads that install into the head are likely a class of thread that is an interference fit. That is they are larger than a common bolt and go into the hole tight to allow the nut to be removed w/o taking the stud with it and to allow for the heat of the part in normal operating conditions i.e. HOT. Tread lightly here or face continuing problems.

I have a stud installation tool for those jobs. Makes it a lot easier.
^ this guy knows what he's talking about . . . . . additionally, talk to the owner of any tube framed Buell . . . .they either are, or know of, experts in exhaust stud replacement.
__________________
"Here is your country. Cherish these natural wonders, cherish the natural resources, cherish the history and romance as a sacred heritage, for your children and your children's children. Do not let selfish men or greedy interests skin your country of its beauty, its riches or its romance. T.R.
bomber60015 is offline   Reply With Quote
Old 03-16-2013, 07:10 PM   #14
mtn500 OP
bush jumper
 
mtn500's Avatar
 
Joined: Sep 2006
Location: Floyd, VA, Edenton, NC
Oddometer: 301
Quote:
Originally Posted by bomber60015 View Post
^ this guy knows what he's talking about . . . . . additionally, talk to the owner of any tube framed Buell . . . .they either are, or know of, experts in exhaust stud replacement.
another guy, the interference thread theory is what I am leaning towards. what is this stud installation tool you speak of?
__________________
certs and destroy

If... the machine of government... is of such a nature that it requires you to be the agent of injustice to another, then, I say, break the law.

When any government, or any church for that matter, undertakes to say to its subjects, "This you may not read, this you may not see, this you are forbidden to know", the end result is tyranny and oppression no matter how holy the motives.


mtn500 is offline   Reply With Quote
Old 03-17-2013, 08:32 AM   #15
vtwin
Air cooled runnin' mon
 
vtwin's Avatar
 
Joined: Jan 2005
Location: NorCal
Oddometer: 7,028


I've gotten them from $nap-On when I worked as a tech. The ones I have are threaded to the common size we used and have a little ball bearing at the end to keep them from tightening on the tool when inserting into the hole. You could even torque them properly, but backs off easily and does not damage the shank like the one pictured could possibly.
__________________
"Alles hat ein Ende--nur die Wurst, sie hat zwei"
Monroe.

"You only have too much fuel if you're on fire"
unknown
vtwin 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 03:34 AM.


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