Exhaust studs and nuts

[FoxTVR430]

I am thinking of adding to the lower exhaust holes these studs, but what type of nuts do I need?
I see a lot of adverts for "brass" nuts. can this be correct?
Also some Nord-Lock washers (10mm) for all the 8x studs + 8x bolts.

[phillpot]

Back "in my day" it was common practice to use brass nuts on exhaust manifold studs.


Is there a reason TVR used bolts, like enough room to pull the manifolds off the studs to replace if required?

[FoxTVR430]

Phillpot, yes I forgot to mention that I intend to slot the lower holes in the manifolds.

[bobfather]

If you use Nordlocks you must use nuts (or bolts) that are softer material so that the Nordlocks can bite onto them. If you use StSt or bolts like ARP that have a hardened surface the Nordlock will not operate and will actually make loosening more likely. What ever you choose try to buy rolled threads rather than machine cut because machine cut threads can grab the soft threads in the heads and strip them. I lost partial thread on a couple of head threads when I removed my original bolts. Thankfully there was sufficient thread left in place to secure my new manifolds

[motul1974]

For what its worth; Clive Ford recommend ARP bolts to me for his manifolds....guessing the man knows a thing or two about TVR's and exhausts!

[bobfather]

motul1974 said:

For what its worth; Clive Ford recommend ARP bolts to me for his manifolds....guessing the man knows a thing or two about TVR's and exhausts!

ARPs are great, just don't combine them with Nordlocks

[motul1974]

Oups....I went with the nordlock option, but yet to fit them.

[bobfather]

motul1974 said:

Oups....I went with the nordlock option, but yet to fit them.

If you have hardened bolts you can still use Nordlocks. You need to give the Nordlocks something to bite on. I used a centre pop to roughen the bolt flange surface. Bolt upside down in a vice and pop away at the flat surface. It worked for me though I did eventually replace the ARPs with rolled mild steel bolts

[SteveR1979]

So I shouldn't have bought these then:

https://www.actproducts.co.uk/product/ms17c-arp-ga...


???

[motul1974]

That's what I have too, minus the gaskets. As I mentioned, Clive Ford recommend the bolts....but didn't mention the Nordlocks if I'm being honest. I'm sure they be fine and I'll take bobfather advice and rough the washers up a little.

[bobfather]

motul1974 said:

That's what I have too, minus the gaskets. As I mentioned, Clive Ford recommend the bolts....but didn't mention the Nordlocks if I'm being honest. I'm sure they be fine and I'll take bobfather advice and rough the washers up a little.

Roughen the bolts, not the Nordlocks. Nordlocks come with teeth that need to lock onto both the blot and the manifold flange. Mine bite the manifolds okay but they spin very freely on the ARPs almost like a bearing, that makes loosening very easily. Once I pop marked the ARPs I could tell the Nordlocks were working because it was hard to get the initial turn to loosen as I removed them to fit new gaskets

[motul1974]

Ok....many thanks