Replacement manifold nuts

[Anonymous]

I am hoping to do the precats at the weekend and would like to replace the manifold to block and cat to manifold nuts with something of a better quality than standard.

Does anyone know the specification of the nuts and what material would be best, from memory manifold nuts always used to be Brass.

[spit]

Don't look like brass to me, but I renewed mine with new MrT parts 2 years ago and they're fine, and the Man nuts have been used again on the C2 install - they don't seem any the worse for it.

Manifold nuts have a spinning washer face and relatively low torque setting (37Nm/27ftlb).

Man to Cat are locknuts to between 62Nm/46ftlb, the man-cat stud bolts should be re-usable, but if you replace the old ones, the new ones go in at 43Nm/32ftlb.

If you really want to be thorough (and unecessary!), you might be replacing the two bolts on the Manifold - engine block bracket. If you do, don't forget they're different size heads (12mm/13mm or 13mm/14mm - can't remember  s:? :? s:?  ). The bigger one is hard to get 'cos its a 10mm thread but finer pitched than your average hardware store will stock. A friendly chat with a MRT mechanic will get you these - they have buckets of them in the workshop  s:wink: :wink: s:wink:  (they're painted green)

[BenF]

I am hoping to do the precats at the weekend and would like to replace the manifold to block and cat to manifold nuts with something of a better quality than standard.

Does anyone know the specification of the nuts and what material would be best, from memory manifold nuts always used to be Brass.

Steve, FWIW I wouldn't bother replacing the nuts - on the Mk1 and Mk2 MR2s (from bitter experience) they're specials costing £1.50 each or so from Toyota. They're high grade metal that can be heat cycled without becomming brittle, and they're usually nipped in at the top a little to 'grip' the stud and stop them shaking loose.

If you put standard M sized nuts on there I'd guarantee they'll shake loose in less than 1,000 miles of driving.

At the end of the day, "if it ain't broke, don't fix it" applies  s:) s:)

[aaronjb]

Yep, they are certainly a funky shape - I can attest to that.

They also appear to be made of butter  s:? :? s:?  (Certainly couldn't accuse them of being brittle  s;) s;) )

You could do it the old style way I suppose - thick brass nut tightens the manifold on, and a thin brass nut is wound on tight to the back of the first to lock it on. That might work..

I'm now desperately trying to remember what the nuts are - M8, I think..