Header Nuts

[RussMcB]

Just wondering if folks in this community have recommended best practices for keeping header nuts tight.

One thing I wonder occasionally: If I use thread locker during initial installation, when I go back later and retighten, does that "unlock" the thread locking compound?

My Kawasaki has studs and nuts. I assume most modern bike engines are the same. I'm using all-metal locking nuts with a wide base flange. They are nice, but I've used them for a while and they may not have a lot of locking grip left in them. Also, whenever I install a header, it doesn't seem long before it has "settled" after running on the track and the nuts are no longer holding the primary tubes tight against the engine.

Over on the Sports Racing Forum someone referenced these "Nord-Lock"s, but there were no opinions or experiences posted about them.

http://dsrforum.yuku.com/topic/2368/...-hardware.html
http://www.nord-lock.com/default.asp?url=2.16.37

Thanks for any suggestions.

[Becker Motorsports]

Hi Russ, In my opinion retighting nuts or bolts that have been installed with a thread locking compound compromises the value [strengh] of the lock tight compound. The nord-washers I am not familiar with but one gentleman seems to endorse them, interestig concept, if not to expensive may be worth a try. I use socket head bolts to install the headers on our pinto motor, and over the years I have learned to tighten [torque] them in stages ie: if 12 foot pounds is the goal, I would torque to 8-10-12 in that sequence. In fact I do all my torqueing in this manner for nuts and bolts.
What color locktight are you using?, they have several different strenghts, perhaps going to a stronger strengh may help solve the problem.
regards Ernie

[RussMcB]

I'll use blue Loctitie.

My hunch is that the nuts may not be backing off, but the header vibrations/copper gasket squash, etc. create looseness.

I'll probably run the engine a bit, then take off the nuts one at a time and re-Loctite, retighten. I was just wondering if anyone had great ideas that I've never heard about.

[Paul LeCain]

I doubt Loctite is going to help much. The usable temperature range, depending on type, is 300-450 deg F.

They make higher temperature lockers, Loctite(R) 2422(TM) and Loctite(R) 2620(TM), that are good for up to 650 deg.

[kmt63]

on the west car.we use the non locking flanged nuts.then tighten fairly tight.cant get a torque wrench in where the header is.run it up for a while.then recheck them.this has worked for a few years.when doing a pre race the nuts are always tight.i never use lock tight on things that get this hot.i always thought it would just burn off.

[Charles Warner]

I was just wondering if anyone had great ideas that I've never heard about.

Not a great idea . . . . but . . . . the metal locking nuts deform when used and are not designed for multiple uses. Replace the nuts at the first sign of loosening, and use a gasket material that will not crush very much. What size nuts are you using? I have a large supply of (from memory) 14mm steel locking nuts that are used on the 4AG exhaust studs.

[Paul LeCain]

I have a large supply of (from memory) 14mm steel locking nuts that are used on the 4AG exhaust studs.

Charles,

I need some. The 14 mm refers to the outer hex, right? The threads are 10mm. I can use 10.

Paul

[kadams36]

Russ

Bill Dormandy uses the Nord-locks and is very helpful in explaining what works and doesnt on his car. Here is the thread - his tag is dorbell.

http://www.apexspeed.com/forums/showthread.php?t=32582

[Charles Warner]

Charles,

I need some. The 14 mm refers to the outer hex, right? The threads are 10mm. I can use 10.

Paul

No problems. I hope you can wait a bit. I'm in Europe at the present time and will not be back in Memphis until Aug 25. I'll make sure of the size and get them off to you. email me your address to fattogatto@msn.com please.

[10rmotor]

Russ

The kawi zx10, and zx10R, use the same style nut. After doing an install and heat cycle or two in the garage, re-check them for looseness. One thing thats different on the 10R over the 10 is that the flange is a single piece and doesn't contact the head when tightened, so they bend a little, and this might be a source of a loosening problem. Blue loctite will just burn off due to the heat, so don't bother using it.