nylocs on exhaust studs?

[robebop]

Any reason not to use Nylocs on my exhaust??

[rtbickel]

On the manifold studs?  Those little plastic inserts would probably melt and/or catch fire in short order.

[Burkslaw]

Nyloks are not effective above 250F. Here's an excellent article on fasteners, if you want some rainy afternoon reading:   https://www.hotrod.com/articles/how-to-use-aircraft-fasteners-on-a-hot-rod/?wc_mid=4035:19899&wc_rid=4035:762138&_wcsid=61AF3CB1CCA6571117BB8C1165E9A09A0BF55682539CA0CE

[Bert Remington]

Nord-Lock washers https://www.nord-lock.com/nord-lock/products/washers/

[Guzzistajohn]

metric lock tite

[Roebling3]

Any color loctite is on the fringe of worthwhile on exhaust studs. I'd use a split lock washer. They have some history.  R3~

[John A]

I just use schnoor washers and silver antisneeze with domed nuts. silver is usually nickel based but the reason I use that is the color blends in better than copper based antisneeze.  I tried heat resistant lock nuts but it would pull the studs out too frequently.  I check them after a few hot-cold cycles and after that they don't change.

[Muzz]

There are things , I think they are called crush nuts.  The top of the thread is tighter at the top.  They work well but can sometimes undo the stud out of the head instead of actually undoing.

[Guzzistajohn]

There are things , I think they are called crush nuts.  The top of the thread is tighter at the top.  They work well but can sometimes undo the stud out of the head instead of actually undoing.

I've also heard them called stover nuts

[Muzz]

I've also heard them called stover nuts

Ya learn something every day!.  Thanks John. ,sadly I will probably forget by tomorrow and go back to crush nuts.

edit: just did a search and you are 100% correct John.

[lucky phil]

A properly torqued plain nut lubricated with anti seize compound wont loosen off in an exhaust header installation.

Ciao

[Guzzistajohn]

Ya learn something every day!.  Thanks John. ,sadly I will probably forget by tomorrow and go back to crush nuts.

edit: just did a search and you are 100% correct John.

Used them in overhead lift equipment for handicapped patients. Gotta be for sure X2 

[mechanicsavant]

+1 on the article from “Hot Rod” . I got it in my “Special 411”folder 

[roadventure]

Any reason not to use Nylocs on my exhaust??

Where, in particular on the exhaust system?

[Groover]

Would these be a good alternative?

https://www.aircraftspruce.com/catalog/pnpages/AN363-720.php?gclid=EAIaIQobChMIhbCnj8n66wIVRNbACh0oagmdEAQYAiABEgKz0PD_BwE

[Old Jock]

I often find that these nuts will loosen after initial application, I'm just not as meticulous as Phil

I use Aero Nuts as posted by Groover, Nord Locks are also excellent as mentioned by Bert

Definately not Nylocs they'd just melt and make a mess

[acogoff]

    Plain nut with schnoor washers and a retorque once a week for a couple weeks or so. 

[lucky phil]

I often find that these nuts will loosen after initial application, I'm just not as meticulous as Phil

I use Aero Nuts as posted by Groover, Nord Locks are also excellent as mentioned by Bert

Definately not Nylocs they'd just melt and make a mess

Maybe I should preface my previous comment John. After initial tightening you need to go back after a short while/heat cycles and tighten them up again. Its not the nuts backing off its the header gasket compressing so they need a re torque like a composite head gasket. After that they will stay tight without the need for some abominable thing like a schnor or spring washer.

Ciao

[ridingron]

There are things , I think they are called crush nuts.  The top of the thread is tighter at the top.  They work well but can sometimes undo the stud out of the head instead of actually undoing.     

I think crush nut is shop slang term. I think Stover is a brand name like Crescent for adjustable wrench. I have also heard the term prevailing torque nut for the crush/Stover nut.

They do have a tendency to tear threads on the bolt/stud. I have seen anti-seize spec'ed as an attempt to prevent that and to increase the accuracy of the torque. The anti-seize would probably melt away after a few heat cycles, in this application.

[lucky phil]

I think crush nut is shop slang term. I think Stover is a brand name like Crescent for adjustable wrench. I have also heard the term prevailing torque nut for the crush/Stover nut.

They do have a tendency to tear threads on the bolt/stud. I have seen anti-seize spec'ed as an attempt to prevent that and to increase the accuracy of the torque. The anti-seize would probably melt away after a few heat cycles.

I used them in aviation for 40 years and just used to get them out of free issue. We just called them pressed metal nuts as opposed to your usual AN or NAS fastener. Ducati have used copper nuts with crimped ends on their exhaust manifolds for the last 20 years or so. I've never had an issue with exhaust flange nuts coming loose on bikes or cars but like I said I check them once after initial torquing down to account for the gasket creep.

Ciao