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Exhaust manifold nuts
ceebmoj - 12/3/12 at 10:43 AM

Hi guys,

I notice that the nuts on my manifolds are in the habit of coming undone. Looks like the builder noticed this two because some of them have been replaced with nylon lock nuts. Am I correct to assume that nylon lock nut are not the right thing for the job if they are not the right fastener for the job what is every one else using for the job?

1. Using a second nut as a locking nut.
2. Locking washer.
3. binx nut

JAG - 12/3/12 at 11:10 AM

None of the above as my exhaust manifold nuts don't come loose - I'd be trying to understand why they're loosening first.

Most modern exhaust manifold nuts are either Copper or Copper plated to avoid heat related corrosion problems. Otherwise I'm not aware that they're much different to other nuts. Are you tightening to the correct torque setting?

Nylock nuts are definitely wrong - I would expect the exhaust manifold temperatures to melt the nylon insert within a few miles.

spiderman - 12/3/12 at 11:28 AM

Brass nuts. Copper is too soft.

[Edited on 12/3/12 by spiderman]

SJL - 12/3/12 at 11:30 AM

I used aerotight nuts on my Busa they have been on there for 3 years now and have never come loose. Like a binx nut but better

http://uk.rs-online.com/web/c/?sra=oss&searchTerm=aerotight+nuts&x=0&y=0

A friend also uses them on his turbo fireblade with no issues

adithorp - 12/3/12 at 11:43 AM

There are specific manifold nuts available. basically ther're a copper coated nut with a crimped section at the end to lock them

ps. I have them in stock if you wanted to pick them up.

[Edited on 12/3/12 by adithorp]

loggyboy - 12/3/12 at 11:43 AM

take your pick:
http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p5197.m570.l1313&_nkw=manifold+nuts&_sacat=See-All-Categories

ceebmoj - 12/3/12 at 11:58 AM

quote:
Originally posted by SJL
I used aerotight nuts on my Busa they have been on there for 3 years now and have never come loose. Like a binx nut but better


'aerotight'

Thanks for that was trying to remember the name.

SJL - 12/3/12 at 12:06 PM

No problem how many do you need? I have some M8 X 1.25 unused here if it helps? I am guessing probably 8 of them lol. Drop me a message if you want them.

Steve

dhutch - 12/3/12 at 01:16 PM

If your really pushed, a standard nut thats been slightly ovalised (hit with hammer, in vice, etc) works quite well, you can but them like said for the same purpose.

Daniel

spiderman - 12/3/12 at 02:52 PM

quote:
Originally posted by spiderman
Brass nuts. Copper is too soft.

[Edited on 12/3/12 by spiderman]


oops. I should have said bronze not brass, as brass is also too soft.