DOHC exhaust manifold

[alga]

Good on ya Sylvain! Making progress on the cheap is the name of the game, you'll always be able to improve it if you feel like it when the car is done.
Was the cast iron hard to weld? Did you do any special prep like heating it cherry red?

[Matthew]

That's a really tidy job. If I hadn't done as much work on mine as I have already I'd be tempted to do the same.

Matt

[voucht]

Thank you very much for the comments guys.

Albertas, no, I didn't find the cast iron that difficult to weld. Of course it is melting quickly, but there was no particular difficulties with the MIG, as the steel thickness of the elbow is much smaller than the cast manifold. And I haven't particularly prepared it except for the cleaning-grinding-degreasing part. Should I have ? For what reason ?

Anyways, after de-rusting the manifold by electrolysis (I just love this process, it is magic!)


2013-09-18_11-07-22 par Voucht71, sur Flickr

... plug-welding the Scorpio sensor holes...


2013-09-18_13-25-29 par Voucht71, sur Flickr

... some smooth black high temperature paint...


2013-09-19_17-38-37 par Voucht71, sur Flickr

... it gives a nice finish.


2013-09-19_17-42-18 par Voucht71, sur Flickr

Would be great if the whole engine was looking the same... may be one day !

Thanks.

[alga]

Usualy cast iron is near impossible to weld as it cracks when cooling after welding, so the weld seam just falls off. But great if it worked out for you, probably the metal used for the exhaust manifold is not the simple cast iron, due to the extreme thermal stresses it experiences.

[flyerncle]

I have done it many times with mig,but understand your thoughts Albert.

It should not work as they are different metals and should be welded by using the "buttering "method with special rods and MMA not mig,I have brazed it as well and that posed no problems,best results with MMA and pre-heat and peen after weld run.

[baz-r]

if you want to weld cast iron with a mig clean it, pre heat it then weld with 316 or other high nickle stainless wire, then alow to cool as slowly as possible