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[ferretjuggler]

I've just broken a chunk out of the exhaust manifold on my Isuzu C240 engine (CJ7 commercial)
Due entirely to me trying to be a clever bugger and turn the broken off studs out by welding nuts onto 'em.
It was working too, but I reckon I put a bit too much force on the casting, and broke the casting away next to the hole.
Anyone know to a midlands based specialist who can weld it up properly (ie with the manifold pre-heated)
I dread to think how much a new manifold would cost.

[Jonny Jeep]

You could try searching "welding" in your area on 192.com

I entered Shrewsbury as the location and 24 companies come up. You might have to phone then to find out about cast though. The link at the top of the page wouldn't have directed you directly to the search so not posted it.

[Dave69]

dont want to put a downer on this but, any company who will do this for probably wont guarantee the weld. cast is  PITA to do and even heating the metal doesn't guarantee a firm weld. this is all down to what stresses are in the manifold from the casting process. Greggmo might be able to add some light on the process

[Bubba]

cast rods and the oven on nuke

[greggmo]

yup. cast rods are needed and they are not cheap for a start. if you then weld up the job it must not cool to quickly or it will crack. you need to pre heat it a touch then bring the temperature down slowly after welding. it is doable though. there is no black art.

[eastryjeep]

How large is the broken out segment and is it in a place where you could get it metal stiched?

Another problem you may find is that post welding the material is so bloody hard you can't redrill it leave alone recut a thread in it!

[ferretjuggler]

Cheers Guys
Unless I can find a used one I'm gonna pay someone to pre heat this thing properly.
The industrial C240 used a tractor type manifold, but Isuzu were suposed to have used this engine in pick up trucks somewhere.
Any ideas where/which vehicle?

[JamesH]

I've had some welding done on cast parts (steering knuckles) by a local engineering firm. I wouldn't say it was complicated, just required pre-heat and a high nickel rod (I think) and then some heat as it was cooling - all as Greggmo said. I would be surprised if you couldn't find a local welding or engineering place that couldn't do it.

Alternatively (and a bit more expensive) what about getting a new tubular one made up. It would last a long time and should give a little bit of a power gain.

[captain cavalier]

IF you are really desperate I work for a company that supplies welding consumables and gases

I can get you a name but it would be in the birmingham area

[Manda]

Did you get it sorted yet?

[scrw]

JB Weld  

[greggmo]

jb weld :lol:  :lol:  we should change your name to cowboy

[scrw]

its the future don't you know

[thorna]

Just a thought:
I frequent another online forum for one of my other cars; a Fiat Coupe.

These cars are guranteed to blow the cast iron 5 branch exhaust manifold at some point. The Italian junk casting is full of sand!

Mine did & I got in touch with a guy on there whos a Blacksmith by trade & now specialises in repairing coupes (lots of work then) based in Hereford.

Every month he does a batch of 10 fiat manifolds, he would do your Jeep one I'm sure no probs. I don't believe he's ever had one break after repair.

Let me know if you want his contact details

[ferretjuggler]

Cheers Thorna
I'm still working on this one.
I've been told high nickel rods are just what I DON'T need as I'll then be trying to drill and tap a hole that is cast iron (soft) one side, and nickel alloy (hard) the other side. Not good.
If you could PM me with the details of the guy in Hereford that would be a start. Cheers.

[ferretjuggler]

Ahem, CRISIS OVER!!!!! ( I hope)
I decided to take radical action this morning, so after finally drilling out the other broken off stud sucessfully (this was what was holding me up),
I committed a despicable act of bodgery which I'm now rightfully proud of!
I drilled the damaged hole right through with a 8.5mm(ish) drill then tapped it M10 x 1.5 with a cheap carbon steel tap from a £5 kit.
I nearly came unstuck on that until I realised I had to turn the plug tap into a taper tap with a hand grinder.
In a stroke of luck I found a nice hard piece of engineering quality all-thread for the studs.
I've now got about 10 good treads holding each stud which are loctited in.
The one broken stud in the head drilled out and re-tapped OK, the manifolds are now back on using the old gasket and plenty of exhaust joint paste.
Tomorrow I'll fix up the exhaust system.
Thanks for all the help folks, it's much appreciated.

[Bubba]

well done that bodger

[PtP]

I've now got about 10 good treads holding each stud

That should be more than enough an M10 with a 1.5mm pitch.

I recall my local motor factors sells manifold studs, but I've no idea what the sizes are, but I also recall they have differing pitches on the threads from one end to the other.

[Dave69]

the 10mmx1.5 is the std size for a normal bolt. you can get 10mmx1.25 wich is a fine thread which enables you to put a higher torque on the bolt. not sure that it is relevant to a manifold. don't forget to use some of the antisieze compound on the thread. this normally cooks and goes solid after a few days but the stuff round the threads should be sufficient.