Classic cars forum & vehicle restoration.

MattF

Ok so I've been knocked back on getting my S1 on the road because it sounds like i have an exhaust leak Sad

Its not the gasket, atleast I've resealed them pretty well so I dont think it can be them. The warant of fittness guys thought I could have a cracked exhaust manifold, has anyone had any experiance with this before?? If so is there a way to fix it? Thanks guys Smile

Rick · Site Admin Joined: 27 Apr 2005 Posts: 22449 Location: UK

That's a pain, repairing a cracked (presumably cast iron?) manifold is far from easy and one for the pro's to tackle, if that's actually the problem.

If I were you I'd be looking to source a better replacement. First thing though is to find out for sure if it is cracked or not, then move accordingly. Are you able to get a small mirror and light down behind the manifold, to try and spot a split in it?

RJ
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goneps · Posted: Thu Jul 10, 2014 10:05 pm Post subject:

My advice as a first step would be to join one more of the Morris clubs. Both the Morris Register in Auckland and the Morris 8 Tourer Club in Christchurch supply some new parts and have spares sheds stocked with used items. Good used parts are normally sold for nominal prices. In addition to the availability of parts you'll benefit from contact with other owners and the practical help and advice they can offer.

Richard

MattF · Posted: Fri Jul 11, 2014 10:02 pm Post subject:

Thanks Richard, I am actually a member of the M8TC and the club rooms are just a 5min drive from my house Smile

lucky me!!
Having gotten a replacement manifold and brand new gaskets fitted last night i'm still hearing the exact same hissing sound as before - by exact i mean its no worse and no better and same tone exc. Weird rite? I think its got to be something else, maybe in the carby? thats making the sound. Will try and get one of the more experienced guys in the club to pop around and give it a listen.

goneps · Posted: Fri Jul 11, 2014 11:33 pm Post subject:

Matt,

It could be either a problem with the mating face of the block, or the joint between manifold and exhaust pipe. Originally the latter had a short steel cone between the pipe flare and manifold flange, and a leak might occur if this is missing. With engine running, try feeling around the join for escaping gases, taking care not to touch the hot parts.

There have been many variations in the way pipes are flared. Mine, which was sourced from the M8TC many years ago, has a flare that does not need the cone because it protrudes slightly above the face of the bottom flange and mates directly with the gasket.

Minor leaks at this point can be fixed with Maniseal or Gun Gum, though ideally it should not be necessary to resort to such measures. I simply coat the copper/asbestos/copper gasket with Copaslip, and a perfect seal results.

Richard

ka · Joined: 03 Dec 2007 Posts: 600 Location: Orkney.

The last comments also triggered my mind. I always use grease on a flange fitting exhaust joint, this allows the two sides to slip into alignment that usually stops any leaks, the grease burns off quite quickly, just to allow slippage.
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KA

Better three than four.

bjacko · Posted: Sat Jul 12, 2014 7:49 am Post subject: Morris 8 Exhaust Leak

Try squirting a few drops of Redex or similar in the air intake at the carby i.e. air silencer if fitted removed, and if there is a leak you will see the smoke at the leak.
It may well be the air intake that is hissing even with the silencer fitted..

MattF · Posted: Sat Jul 12, 2014 12:45 pm Post subject:

Thanks Richard my old manifold was just stuck on to the engine block with some clear silicon like product, didnt even have a gasket!!! I think thats probably because it was actually a good fit and just didnt need it but time will tell. As for the exhaust connection thats a totally different story - I have tried to redo that joint so many times its not funny. I did even try putting maniseal between the cone and the flanged exhaust but if this actually held it off then would I be right in thinking that anything I try to do after this will just never seal properly? Having read what you have said KA I think this could possibly be the problem so I may look at taking that part of the exhaust out and cleaning all the crap off from around there then I'll use your grease idea Smile

Also whats Redex??

Jim.Walker · Joined: 27 Dec 2008 Posts: 1229 Location: Chesterfield

Redex is an upper cylinder lubricant which was supposed to reduce carbon build up around valves and pistons etc. Not so easily sourced these days.
Nowadays, modern oils and fuels do not leave such massive carbon build up.
Carbon build up used to be so bad that engines needed de-coking (de-carbonising) almost annually. In your case the object is to produce smokey exhaust gases to find (see) a leak so 3 in 1 oil or similar should do.
Jim.
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Quote from my late Dad:- You only need a woman and a car and you have all the problems you
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goneps · Posted: Sun Jul 13, 2014 1:08 am Post subject:

Matt,

Just a thought—have you got the type of exhaust pipe with flexible section alongside the sump, as supplied by the M8TC? These are inclined to leak; when mine started blowing I had it cut out and a straight section of pipe welded in. These were fitted to late production Eights and in my view are both pointless and unnecessary.

Richard

ka · Joined: 03 Dec 2007 Posts: 600 Location: Orkney.

"Also whats Redex??"

This is a statement and half, dividing a generation.
I remember when my dad was driving, and pulling into one of the many fuel stations that were about, there was always a triangular Red-Ex sqirty can, and nearly always a pump dispensing two-stroke. When I started driving, Red-ex was available in the shop, but very few sqirty cans, and very few two stroke dispensers.
It is also quite amazing how we used to have to de-coke an engine, another phrase committed to the history books.
_________________
KA

Better three than four.

MattF · Posted: Sun Jul 13, 2014 8:53 am Post subject:

Richard - I got my exhaust off Richard Rowe - you may know him, one of his old exhausts that he got made up, and no it hasnt got a flexi part - I've had to much on today to try the 'black smoke' idear will try it one night this week.
KA - regarding what generation im part of, well I'm 24 so that tells you why I dont really know about all the things that were just a part of normal life only a few years ago Wink

Jim.Walker · Joined: 27 Dec 2008 Posts: 1229 Location: Chesterfield

Matt,
Just a little very light oil should produce visible blue/grey smoke as if the engine is using oil. Which in effect is what you need to simulate.
I'm not sure how much would be needed to produce "black smoke" but it surely would not do many things much good.
By the way, the flexible exhaust inclusions used to be used when exhaust systems were bolted rigidly to the chassis so that the "rocking" of the engine would not fracture the system.
When someone had the bright idea of using flexible mounts they pretty well disappeared. That practice came in about the time that exhausts had to be hung on monocoque structures (1950s/60s?).
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!