Souder un bloc moteur fissuré / Welding engine block (par David Gâté).

Uploaded by mancamaroZ28 on 13.03.2012

How to weld a steel cast iron engine block.
Hi the handymen !
Today, we're going to see how to weld an engine block which has cracked.
So, if the arc welding doesn't frighten you, and if it doesn't scare you, you can try the experience.
Effectively, if you have an engine block in perfect condition, there is no interest.
The best solution is to put some water instead of the coolant engine, waiting for winter cold temperatures, and notice good cracks !
And after that, you'll have pleasure to repair an engine block that you have just broken !
"This report is offered to you by the Young Singers with their Cast Iron Cross."
Let's note that the weld on a steel cast iron block is a delicate and long operation.
Furthermore, the repairs aren't always 100% guaranteed. It's for these reasons that we often change the engine block rather than to repair it.
But if you are motivated to make the work yourself, know that the cost of a professional or a change of block can be compensated with your handwork and free time.
Let's have a look on our exemple.
It's a Chevy small block with 2 hard cracks on each side. It amounts to more than 15 inches of cracks all in all.
Note we can see a sample on this photo.
What do we do to begin ?
We're going to begin by beginning and...
Then, we're going to take a small cut-off wheel with its little drill, like a good Dremel or first price product...
We're going to groove the crack throughout by digging it first, because it's not easy to see it clearly.
But we're going to accentuate it about 1/15 inch depth, but not more !
Would not you like to cross the block ? Shit ! Don't you think that it's not cracked enough ? Small pervert !
If I can give you an advice to make a success certainly of your weld, it is necessary to...
If you follow my advice, I'm sure that you will make a success.
Before welding, we are going to make a chamfer along the digged crack.
So, what tool are we going to take ?
A small round mill : I confirm !
Here are the chamfered cracks. We can note that the metal chip stays on the crack.
We're ready to weld. Be careful with welding projection and protect high-risk areas (like valve lifters emplacements).
It would be the big bullshit ! Fuck !
There are several contradictory methods to weld an engine block.
Personally, I chose the arc welding with adjustable machine, funny cast iron electrodes, on the chainlet welding method.
And I make maybe a bullshit : all that without preheating the engine block. Am I crazy ?
We're going to make everything possible to limit the thermal shocks, what could cause new cracks.
We're going to realize several welding passes, 1/2 inch each real maximum, by paying attention to let well cool this pass before making another one.
We're not going to make a welding pass as long as the previous one didn't reach the ambiente temperature.
What we can make is to limit the intensity to avoid the superheating.
Well, now the weld is ended, what you should make is to close the cooling circuit, and to put it under pressure (under starting and working engine temperature), to detect some leaks.
And as would say Patrick Bruel (french singer), the most mattering in the weld, this is not electrode, it's what you make with it.