Author Topic: Exhaust header studs/nuts  (Read 7061 times)

0 Members and 1 Guest are viewing this topic.

suitcasejefferson

  • Grand Gearhead
  • *****
  • Posts: 1,589
  • Karma: 0
on: April 09, 2014, 04:07:48 pm
Last week I started hearing what sounded like an exhaust leak. I checked and sure enough the top nut on the head was loose and about to fall off. I tightened it and the noise went away. Yesterday I discovered the bottom stud was loose in the head. I unscrewed it by hand. No thread damage. But now I'm wondering how to keep them in place. No threadlocker I know about will handle that kind of heat. The studs are not long enough to use a lock washer behind the nut. The end of the stud is flush with the nuts when tightened. Usually the problems I have run into have been studs rusted/corroded in the head, and/or broken off in the head.
"I am a motorcyclist, NOT a biker"
"Buy the ticket, take the ride" Hunter S. Thompson


ROVERMAN

  • Grand Gearhead
  • *****
  • Posts: 1,177
  • Karma: 0
Reply #1 on: April 09, 2014, 05:20:51 pm
SCJ, i think there is a threadlocker that can handle up to 1,300 deg but i can't think of the number right now. You could use high temp silicone after de stressing the exhaust and torque up to spec. A lock nut probably wouldn't hurt either.
Roverman.


gashousegorilla

  • Grand Gearhead
  • *****
  • Posts: 4,485
  • Karma: 0
Reply #2 on: April 09, 2014, 05:27:15 pm
Last week I started hearing what sounded like an exhaust leak. I checked and sure enough the top nut on the head was loose and about to fall off. I tightened it and the noise went away. Yesterday I discovered the bottom stud was loose in the head. I unscrewed it by hand. No thread damage. But now I'm wondering how to keep them in place. No threadlocker I know about will handle that kind of heat. The studs are not long enough to use a lock washer behind the nut. The end of the stud is flush with the nuts when tightened. Usually the problems I have run into have been studs rusted/corroded in the head, and/or broken off in the head.

  Locking flange nuts work well, forget the size off hand ?But McMaster Carr has them....

http://www.sv3power.com/store/images/EX9N8S.jpg
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


no bs

  • Grand Gearhead
  • *****
  • Posts: 583
  • Karma: 0
  • if it's got two wheels i'm on it
Reply #3 on: April 09, 2014, 08:20:01 pm
8mmx1.25
killing bugs since 1972 2011 g5 deluxe frankenbullet


Ducati Scotty

  • Grand Gearhead
  • *****
  • Posts: 7,038
  • Karma: 0
  • 2010 Teal C5
Reply #4 on: April 09, 2014, 08:50:10 pm
http://www.mcmaster.com/#93795a230/=rgr7cb

Not reusable, so order a smal bunch and keep them on hand.

Scott


Bulletman

  • Grand Gearhead
  • *****
  • Posts: 773
  • Karma: 0
  • 2011 - C5 Classic Black
Reply #5 on: April 09, 2014, 09:21:38 pm
  Locking flange nuts work well, forget the size off hand ?But McMaster Carr has them....

http://www.sv3power.com/store/images/EX9N8S.jpg
GHG, Ducati Scottie, I NEED TO RE-Adjust my muffler as the part at the bottom is kinda touching my brake pedal. Is this an easy process..I mean is it as simple as loosening the 2 header nuts, adjusting the muffler and re tightening ?
Curious minds want to know  ;)
"A Blast from my Past"
Black C5 2011


Ducati Scotty

  • Grand Gearhead
  • *****
  • Posts: 7,038
  • Karma: 0
  • 2010 Teal C5
Reply #6 on: April 09, 2014, 09:26:42 pm
Kind of.  But the header pipe needs to seat flat into the head, there's not much wiggle room.  You can rotate the header a bit but you can't completely re-orient it.  Also, the header feeds into the muffler.  You can only wiggle it so much, especially if you have the stock muffler that is bolted on in two places. 

An easier solution might be to lower the brake pedal a little.  Go back near where it pivots and you'll see a bolt with a lock nut.  Loosen the lock nut and you can adjust the pedal height.  Then just re-tighten the lock nut.

Scott


gashousegorilla

  • Grand Gearhead
  • *****
  • Posts: 4,485
  • Karma: 0
Reply #7 on: April 09, 2014, 09:43:57 pm
Kind of.  But the header pipe needs to seat flat into the head, there's not much wiggle room.  You can rotate the header a bit but you can't completely re-orient it.  Also, the header feeds into the muffler.  You can only wiggle it so much, especially if you have the stock muffler that is bolted on in two places. 

An easier solution might be to lower the brake pedal a little.  Go back near where it pivots and you'll see a bolt with a lock nut.  Loosen the lock nut and you can adjust the pedal height.  Then just re-tighten the lock nut.

Scott





 Yup +1..  The header MUST sit in the exhaust port straight and true. And tightened down evenly on the studs.  Adjust the brake pedal height it you HAVE to. The second bend down the header should be not quite a 90 degree bend... and slope a little down, to clear the brake pedal.  If you set the header in straight, you may find that the connection at the exhaust port is cocked.

  I use these nuts.....

http://www.mcmaster.com/#94920a500/=rgrrn5
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


barenekd

  • Grand Gearhead
  • *****
  • Posts: 5,516
  • Karma: 0
Reply #8 on: April 09, 2014, 10:46:40 pm
Blue Loctite will work on the header flange nuts and studs The temps on them is in the 400o range.
Bare
2013 Moto Guzzi V7 Racer
2011 Black Classic G5 (RIP)
I refuse to tiptoe through life only to arrive safely at death
http://www.controllineplans.com


Bulletman

  • Grand Gearhead
  • *****
  • Posts: 773
  • Karma: 0
  • 2011 - C5 Classic Black
Reply #9 on: April 10, 2014, 02:10:42 am
GHG and Ducati Scottie...Thanks...I managed to fix the problem by bending the support bracket for the muffler at the passenger foot pedal..resolved the issue.....
"A Blast from my Past"
Black C5 2011


suitcasejefferson

  • Grand Gearhead
  • *****
  • Posts: 1,589
  • Karma: 0
Reply #10 on: April 10, 2014, 06:15:49 am
Those locknuts would not come off the studs, but the studs would still unscrew themselves out of the head. I can try locktite on them, but I've used heat before on red locktite, and it doesn't take much to melt it. That connection is about the hottest place on the engine. If I can find some longer studs, I could use a split lock washer under the nut, and that might put enough tension on the whole thing to keep it from coming loose.
"I am a motorcyclist, NOT a biker"
"Buy the ticket, take the ride" Hunter S. Thompson


hortoncode3

  • Grease Monkey
  • ****
  • Posts: 310
  • Karma: 0
Reply #11 on: April 10, 2014, 11:40:12 am
As with many things on RE's, running a wrench over the various and sundry nuts every now and then is always a good idea! I especially watch the flange nuts as I have lost a few. Also, it's a great idea to buy a few exhaust gaskets as spares as they deteriorate quickly when the thing does get loose, and it will get away from you at least once..!


tooseevee

  • Grand Gearhead
  • *****
  • Posts: 4,570
  • Karma: 1
  • Everybody's havin' them dreams
Reply #12 on: April 10, 2014, 08:43:05 pm
Those locknuts would not come off the studs, but the studs would still unscrew themselves out of the head. I can try locktite on them, but I've used heat before on red locktite, and it doesn't take much to melt it. That connection is about the hottest place on the engine. If I can find some longer studs, I could use a split lock washer under the nut, and that might put enough tension on the whole thing to keep it from coming loose.

I've used these on my 3 shovelhead engines since long ago. Solves all exhaust stud problems (& shovels only have ONE stud):

http://www.jpcycles.com/product/4420121

There must be a like product somewhere to work on the Enfields?

What wrecks the threads is never checking to see if there's enough tight on the nuts. The pipe vibrates against the loose nut which transfers to the stud which wears the threads out.

RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


ace.cafe

  • Grand Gearhead
  • *****
  • Posts: 14,457
  • Karma: 1
  • World leaders in performance/racing Bullets
Reply #13 on: April 10, 2014, 08:44:46 pm
Use brass nuts, and use some clear silicone sealer on the threads to stop it from backing off.
Home of the Fireball 535 !


suitcasejefferson

  • Grand Gearhead
  • *****
  • Posts: 1,589
  • Karma: 0
Reply #14 on: April 10, 2014, 09:22:48 pm
Thanks for all the great ideas. I put it all back together and tightened it properly. I put almost 200 more miles on it, and checked the nuts 3 times during that time. They did not come loose. There is a possibility they may have been loose from the factory. They are a common size, same as most Japanese bikes use. I will keep an eye out for some just a little bit longer, and put a split type lock washer between the nut and flange. I will also put some silicone into the holes in the head, and screw the studs in all the way. Extra silicone should be squeezed out, so the gap between the internal and external threads will be filled with silicone.
"I am a motorcyclist, NOT a biker"
"Buy the ticket, take the ride" Hunter S. Thompson