Cracked manifold

[Andy_J]

It seems the manifold has cracked on my red elan

Anyone got any suggestions on how to fix it, which dont involve removing it

[lotusgirlmarie]

Hate to say it but if you've gotten that fR you might as well remove it. Personally I'd source a new one. Beats the risk of the weld cracking and having to pull it again.

[supracat]

havent come across cracked manifold on an elan before....our 355 spider started to suffer from this quite a few of the guys in Ferrari owners vlub with 355's have had to repalce their manifolds due to cracking - apparently a weak area!!

i can try to find out where the 355 boys send theirs for repairs if that would help? - i had heard a couple of firms repair/strengthen the manifolds - at approx. £1500 per manifold, 355 needs two, repair/replacement is worth looking at.

[ashm]

Cast iron can be be successfully welded - I've had an old lathe bed repaired this way.
It can be a bit hit and miss sometimes and if it goes wrong you'll be left with scrap, but there are welding shops who specialise in CI repairs.
I'd probably remove it, get a specialist to grind out the crack & repair weld, then it should be straightforward to machine it back if the weld goes well. Depends whether you can get a cheap replacement manifold though!
Adam

[dapinky]

I have seen many elan ones go like this - and if/when you remove it, you'll probably find 2 more cracks on the rear face

The good news is that they still work when like it - and i have had sucess with 2 methods of repair.....

....one was sandblasted down to grey cast iron, then drilled the ends of the cracks and filled with 'chemical metal' (it seems to take the heat well enough).

....the other was welded - not a pretty sight, but works very well. Cast iron can be a diffcult material to weld without the right kit - you won't get a good result with a home MIG kit. Basically, the manifold needs to be heated up to (IIRC) about 600 degrees, then welded, then cooled slowly (in an oven). This is because otherwise the base metal will contract too quickly and the weld (being harder) will cause the cast iron to stress and potentially shatter (only more likely to just extend the current crack.

There may be a local shop who would do it for you, but i was lucky enough to have a mate with access to someone working at Jaguar's experimental depot - unfortunately, no longer available to me

[Andy_J]

Really trying to avoid removing it. Has enough bolts shear when getting to this stage. I don't want to break a std in the manifold.

Think I will try welding it as I have a mig welder and see what happens. If I have to strip it again, then it only takes a few hours

[ashm]

Really trying to avoid removing it. Has enough bolts shear when getting to this stage. I don't want to break a std in the manifold.

Think I will try welding it as I have a mig welder and see what happens. If I have to strip it again, then it only takes a few hours

Hmm fair enough, but I wouldn't if I were you - either let it be or take it to a specialist. Studs are more easily replaced than manifolds! As Pinky says, CI welding is not really a DIY job due to the material being so vulnerable to thermal shock. It'll probably want preheating at least. You can maybe braze it, which might be good enough. If you weld it, be careful in your selection of filler material.
Google provides some discussions: here and here.

Adam

[dapinky]

Really trying to avoid removing it. Has enough bolts shear when getting to this stage. I don't want to break a std in the manifold.

Think I will try welding it as I have a mig welder and see what happens. If I have to strip it again, then it only takes a few hours

Having removed many, i can say that I've never had a stud shear yet - they aren't tight in the head.

Usually many of them will come out when you undo the 14mm nut anyway - the rest will come out with an E6 star socket. I wouldn't expect it to take mor ethan 5 minutes tops - it would take you longer to disconnect the electrics and cover the surrounding area if you were going to weld it in situ. As i say, MIG welding cast iron using mild steel wire is not recomended, but it may work - good luck.

[Andy_J]

Thats it welded, I will see how it gets on. Just gone and snapped 2 of the turbo to exhaust studs. Hope whats left of them come out easily