Crack in a Top cylinder of an Engine

post your question at the AWS site they can point you in the right direction.

cast irons can be welded it just a pain in the butt. and requires tools most welder don't have.

I assume you mean a cylinder head. First off, why did it crack in the first place? Any fix won't be as strong. I have successfully welded cast iron manifolds; by heating the whole item up first, using a good quality welding rod specified for cast iron, and cooling the item down slowly in a hot oil bath. Would it be cheaper to replace the head?

Hello PlbMak, Welding is one option, but cylinder heads have a habit if cracking around the valve seats which can make welding awkward, unless of course its a frost crack. Another option is 'stiching', a process whereby the crack is filled with metal cold but which is of course not fused. I guess whether or not this is feasible would depend on where the crack is and the operating conditions. Bye for now, Hugh Price

It's like you're familier this problem,the crack actually took place around the valve seat, as a result of sudden change in temperature;instant puring of water in the radiator when experiencing overheating and shortage of water in the radiator.

Mr. Price , what your advice to this situation or remedy? David Alonge

Once a crack had been initiated in cast iron, the most important thing is to prevent it from propagating. We used to drill a hole at the end of the crack. A pin was then put into the hole and the crack sealed with crack sealer. The valve seat is likely cracked as well and must be replaced. If the seat is not the replaceable type, the head must be machined to accept a replaceable seat.

Hello Guest,

My grandfather had a block with a crack through the cylinder wall. He brazed it back together and it ran fine for another 50k miles until he sold the vehicle.

I had an old plymouth 360 engine that I bought at a junk yard. I took it to the local engine machine shop and had it balanced and rebuilt. The machinist showed me that he had repaired some hairline cracks in th heads, but never elaborated on how he did it. I would suggest taking your heads to the local engine rebuilder and see what they could do with them.

DAG

Very carefully

Cast Irons are typically repaired by grinding out the crack and buttering surface with Ni rod with controlled heat input. Then, weld the joint with low hydrogen rod.

Machine surface and hone.

Make sure cooling rate is slow. I recommend using an oven to slow cooling rate and preheating in an oven prior to welding.

The Ni rod ties up the excess carbon to avoid formation of martensite.