Exhaust Fittings & Copper SliP?

RichardB uttered summat worrerz funny about:

Personal thoughts are it'll burn off.

I fear the only soloution is a good soaking before removal in plus gas or even diesel next time around.

Often find that such a simple task is made mamouth by the need to replace studs.

Percy (IIa with the Jag lump) had Copper / brass ? I forget nuts on the manifold to down pipe. they were designed to be oval to form a lock nut and never had any rot on them, though they were not at all cheap and OE parts from Jaguar.

Lee D

It won't do any harm but depending what you use may not, as you already suspect, do much good either.

Genuine Copaslip does quite a good job but there are many imitations which are as good as useless. There are some that intentionally provide 'dry' lubrication when they get really hot (e.g. Wolfracote TOP).

You're safe from things going 'rock hard' - the poor ones just disappear! Brass or Helicoil nuts also work. The problem with brass ones is that you may need to tighten them more than they will stand. The Helicoil ones can corrode leaving only the stainless coil.

Copperslip won't last long with the temperatures involved, but it's probably better than nothing. Generally I use brass nuts on manifolds and downpipes and hi-grade stainless nuts/bolts on the other flanges. Brass nuts are a two-edged sword because whilst they don't corrode on, you cannot get them as tight as steel nuts, so they can come undone. It's not recommended to re-use them either. If the gasket requires a lot of tightening, then you could clamp it up tight using steel nuts, let the gasket compress for a bit and then replace the steel nuts with brass ones. Square.spring washers also help if using brass nuts.

Alex

On or around Sat, 02 Sep 2006 18:50:49 +0100, RichardB enlightened us thusly:

like they said, brass nuts, but they're difficult to find. proper ones are thicker than steel nuts so they're strong enough.

If you put stainless steel nuts on, then at least the nuts don't rust... stainless and copper grease, I reckon. The copper will stay there, even if the grease part burns off.

when doing the sort of joints with bolts, stainless ones.

Nickel based anti-seize seems to handle the heat better and does a good job.

I use copper slip - the real stuff - it does burn away, but that's the whole point, the grease element burns away leaving a coating of copper & lead etc behind.

My preference is to use brass nuts - I make my own, it's only a minute's work to knock them out if you have a lathe & the appropriate size of tap. I make mine about 1/2" deep (this for a 5/16 UNF) to give them extra threads so as to enable a bit more tightening. 1/2 A/F brass stock is readily available - my local non ferrous supplier is happy to flog me slightly bent stock as auto lathes can't use it, whereas my little Myford lathe handles it fine when it's cut up a bit.

On or around Sun, 03 Sep 2006 12:10:45 +1000, Duracell Bunny enlightened us thusly:

'course, not all LR owners have a lathe...

I could do metric ones easy enough if I find a supplier of brass hex stock.

Soaked in penetrating oil for days before I attempted the job! However I did use it so I guess that just burns off too.

I like the idea, that has been suggested elsewhere in thread, to us brass nuts after tightening up with steel ones.

However, would stainless steel nuts not have similar resistance to corrosion as the brass ones?

Regards

RichardB

I'd love to have the skills and hardware to make my own. However, I struggle with a spanner and hammer so no chance!

Looks like the answer, for me, is good quality copper slip (noting that the grease burns off and leaves the copper...) and stainless steel fittings.

Now I just need to get the broken stud out so that I can fit the new down-pipe. Will have to wait as it's a bit wet outside at the moment....

Regards

RichardB

Don't use stainless - it locks up absolutely solid and becomes brittle with the heat. And when you you snap it it's nigh on impossible to drill out because it also becomes bloody hard.

I tend to use Toyota exhaust studs and nuts (with anti-seize) which are semi-stainless and don't seem to either snap or lock up (and are still drillable if the worst happens). So far (touch wood) I've never broken one. M10 head-to-manifold studs off most of the 90's Toyota engines do the job after a bit of judicious re-tapping of the appropriate holes.

Noted! When I finally get the stud out I'll use copper slip and ordinary steel nuts.

Having read the label on my tin of copper slip is says it is effective at over 1000C.

Regards,

RichardB

On or around Sun, 03 Sep 2006 21:55:09 +1200, EMB enlightened us thusly:

stainless nuts on plain steel studs are OK, IME though.

Brass nuts are the cure though. how much will people pay for 'em if I make some :-)

Austin Shackles uttered summat worrerz funny about:

Like I said , I got some from Jaguar OE cira 1978 XK lump exhaust manifold.. I'd be a pound to a pinch of doo dah they are the same thread. they were about 3x the lenth of a conventional nut too and oval by design to make them lock on that bit sooner before the threads are ripped out.

No doubt an on line classic jag specialist / ebay will turn up the thread sizes.

Lee D

I wonder?

Ebay.

Lee D

You've got plenty of time to make some up. Still not got the effing stud remnants out.....:-(

RichardB

On or around Sun, 03 Sep 2006 19:17:38 +0100, RichardB enlightened us thusly:

yeah, but I've not got any hex brass stock... Given the stock, nuts would be a doddle. I've seen 'em for sale, in Halfrauds of all places. But the modern ones are normal nut sized, and wouldn't be strong enough. Traditional

All the old motors used to have brass nuts on the exhaust manifold and on any exhaust flanges.

Each unto their own - I always find they pick up on the threads and strip the stud (or it snaps).

I can buy them off the shelf for sod all money (well under a quid each) but I find they tend to work loose unless a long stud and locknut is used.

A couple of weeks ago I replaced the exhaust gasket on my 110 (3.9 diesel), which comes as standard with brass nuts on the exhaust pipe (but not the studs in the head strangely). About fifty kilometres later it started making a noise again - two loose brass nuts, and one missing. As the nearest shop selling such things is 60km away, I made a replacement nut - and three lock nuts. No more problems (so far anyway). JD