Exhaust Manifold Errosion

[neil1967]

I recently removed the exhaust cooling mixer elbow from my Perkins 4108 to check its condition. Having done so, I noticed that the manifold it's self, where it joins the elbow seems to have suffered Errosion/corrosion inside and that the first inch or so of the inside of the manifold is quite rough and irregular, although there is still plenty of metal there. The surface of the manifold where the exhaust elbow is bolted on to is fine, so i am not worried about exhaust gases leaking out. Is this just poor manufacturing (ie is it normal)? If not, is it worthwhile using a high temperature metal epoxy to restore the inside of the manifold, or should I just leave it? My concern with leaving it is that if I were to ever get any water going backwards into the manifold, it would accumulate there - or perhaps that is what caused it in the first place? If filling is a good idea, any suggestions for a suitable epoxy?

Thanks

Neil

 

[guernseyman]

...Errosion/corrosion ...

Despite the similarity of the two words - both coming from the Latin 'rosum', the first has the prefix 'e', while the latter has the prefix 'cor'. Hence erosion and corrosion.

 

[Swanrad2]

This is supposed to be the best stuff (I got some off e-bay, its expensive but used for filling blocks let alone manifolds):

Belzona 1111 Mixed 400g (333g base + 67g) Super E-metal ...

If the damage is bad enough then there are one or two places in the UK that can weld the casting - they have to heat it until it is cherry red and then weld. There is a high chance of cracking though, Belzona is very highly recommended by those who have used it - I was lucky enough to find a spare. Apparently you can get a stainless steel set of pipes made up, although I have no idea how or by who.

 

[LadyInBed]

Exhaust Manifolds seem to be prone to 'rot' from hot salt water and exhaust gasses.
Mine ate through after about eight years. I'm sure Vyv Cox can give you chapter and verse, it might be worth looking on his website.
If you have yours off, it may well be worth getting one made up in stainless.

 

[NormanS]

Presumably it's a dry manifold, onto which the water-cooled elbow is attached. If so, I wouldn't be too concerned about it, unless you think it has lost metal and might be about to start to leak exhaust gas.

 

[LadyInBed]

Sorry, misread your post and getting my manifolds mixed up with my elbows :nonchalance:

 

[James_Calvert]

Presumably it's a dry manifold, onto which the water-cooled elbow is attached. If so, I wouldn't be too concerned about it, unless you think it has lost metal and might be about to start to leak exhaust gas.

+1

The insides of manifolds are normally pretty rough - it is after all a casting. I'd check it for lost metal and any cracks. Do you/ does anyone know if this Perkins type has any history of problems with manifolds?