Nut & Spring Washer or Nyloc Nut?

[Andy 308GTB]

In the quest to replace a pair of exhaust manifolds, I have emptied a considerable amount of my engine bay.
Much of stuff coming out hasn't been touched in 35 years, so the nuts and spring washers coming out are the original fixings.

Since I am working on a car, not a historic artifact, is there any technical reason why I cannot replace these with Nyloc Nuts (and where necessary plain washers). I guess that Nyloc Nuts can't be used where stuff gets really hot (i.e. joining exhaust manifold to exhaust box etc.)

[one eyed mick]

Source your local fastener supplier and call with cash ! what you need go under many different names , stiff nuts ,hoddy nuts etc ask them for what they are known as locally . Nylocs will prob melt ,old school is brass nuts and spring washers !!

[Andy 308GTB]

one eyed mick said:

Source your local fastener supplier and call with cash ! what you need go under many different names , stiff nuts ,hoddy nuts etc ask them for what they are known as locally . Nylocs will prob melt ,old school is brass nuts and spring washers !!

Sure, where stuff gets very hot I won't use Nylocs.
But on general bits and pieces, there is no reason to persist with Nuts and Spring Washers?

Hoddy Nuts - did you make that up?

[Boosted LS1]

Ask for aero nuts and washers.

[aww999]

K-nuts work well on hot items, ideal for manifolds. Similar principle to nylocs, but the bylon part is replaced with a deformation in the body of the nut which grips the bolt thread.

[Andy 308GTB]

Thanks all, so there are plenty of nut/bolt combinations for joining the exhaust manifolds to the exhaust box.

But... is there any reason why nuts & spring washers should not be replaced with Nylocs in areas that are not subjected to significant amounts of heat?

[JoeBolt]

In certain applications, (where transverse vibration is present) it has been proven that the use of helical spring washers can actually be detrimental to thread locking.

Google Junkers Test: -

http://www.boltscience.com/index.htm?

[Bdevo3]

Nut and spring washer. Don't forget the copper grease for anything got to do with exhausts. Makes things a lot easier if you ever have to remove bolts again

[one eyed mick]

Hoddy nuts ? learnt that 50/60 years ago may be only common in my area North Notts South Yorks Flange nuts are good too

[CrutyRammers]

Andy 308GTB said:

Thanks all, so there are plenty of nut/bolt combinations for joining the exhaust manifolds to the exhaust box.

But... is there any reason why nuts & spring washers should not be replaced with Nylocs in areas that are not subjected to significant amounts of heat?

I'd use nylocs in preference to spring washers personally.

[longshot]

I would use nylocs in preference to flats and springs when possible but I think the heat issue would always be at the back of my mind.

If you want a truly fit and forget solution, I would use k nuts as already mentioned.

There's a reason the aerospace industry use them.
They ain't going nowhere.

[E-bmw]

In answer to your actual question, no there is not.

A few above seem to have skim read your post & think you are going to use nylocs on your exhaust, which obviously you aren't.

Carry on.

[DrDeAtH]

CrutyRammers said:

I'd use nylocs in preference to spring washers personally.

All well and good up to the point that you wish to run the engine I suppose....

[E-bmw]

See my posting above.

READ the post & you will get the right answer in the end!

[Gojira]

E-bmw said:

READ the post & you will get the right answer in the end!

Not likely to happen

Back when the world was young, Ziggy Stardust was a new release and I was at school, we were given a maths test for homework...

The first line read "Read the entire question paper before answering the questions"

The last line read "Write your name clearly on the answer sheet, but do not try to answer any of the questions"

In between were several questions on hard sums we hadn't been taught yet.

We had a sadistic maths teacher, but I passed that particular test

[dudleybloke]

What size do you need?

[Andy 308GTB]

dudleybloke said:

What size do you need?

M6, M8, M10 and M12

[tapkaJohnD]

The engineering test for nut lockers is the Junkers test.
A machine exerts a severe vibration to a tightened nut and bolt, while a load cell measures the clamping force of the nut'n'bolt.

If you search for Junkers test, you will find many examples of tests on various washers and nuts.
This one looks at several, including the Nylock.
It favours the brand of special washer that the company makes, but does show the vastly greater security of a Nylock over a spring washer.
Although the Nylock loosens too, remember that the Junkers is a severe test!

https://www.youtube.com/watch?v=IKwWu2w1gGk

John

[dudleybloke]

Andy 308GTB said:

dudleybloke said:

What size do you need?

M6, M8, M10 and M12

I'll have a look what sizes of clevelocks I've got when I'm back in work.

[CrutyRammers]

E-bmw said:

See my posting above.

READ the post & you will get the right answer in the end!

Thank you!