Can I just Tig or JB weld this cracked block? Why did this happen?

[bertsmobile1]

I use my endoscope regularly, mainly for checking condition of piston, rings, and cylinder. Very helpful tool. Still usually pull the muffler on 2-stroke for better visibility.

We digress here a bit but I do not charge for quotes so when Fred Fool walks through the gate with a no compression hand held I really do not want to waste much time on it
So it is " Probably got a stuffed bore sir , gonna cost $ xyz to fix , see what is on this screen "
They realize the machine is stuffed , most times they know why it is stuffed so they just slink back out the gate & go annoy some one else .

 

[Tornadoman]

Although I have to ask, an impact from what exactly? This is horizontal v twin. Isn't the crankshaft connected to the flywheel? What could have possibly hit inside of there

You might want to repair it if it has some value. That crack can be gently tapped back and then TIG welded, but if it is a low-stress area you might want to experiment with some Alumaweld. I was skeptical when I ordered some but found out it really does work well.

 

[slomo]

You might want to repair it if it has some value. That crack can be gently tapped back and then TIG welded, but if it is a low-stress area you might want to experiment with some Alumaweld. I was skeptical when I ordered some but found out it really does work well.

The alloy in mower blocks is just not raw aluminum. I doubt alumaweld will work. A pro welder might have more 411 on this.

 

[bertsmobile1]

You might want to repair it if it has some value. That crack can be gently tapped back and then TIG welded, but if it is a low-stress area you might want to experiment with some Alumaweld. I was skeptical when I ordered some but found out it really does work well.

They are difficult to use on a crank case and it will probably get too hot in use and the patch will slump or simply blow out
Most melt around the 300 º C mark and go mushy around 250º C
Mower crankcases are usually an Al-Si-Cu-Fe alloy , BP 401 or whatever the US equivalent it
There are a lot of different formulas for those solders so you always have to check the melting point and safe operating temperatures before using them

 

[moparjoe]

27 hp rare Briggs craftsman riding mower from 2005. Got it from my neighbor. Apperantly he was using it and the block cracked here and gushed out all the oil. Why did this happen? Can I just Tig weld it shut and fill it back up with oil and call it good? It's a pretty rare engine and would like to salvage it if possible

If it is rare , what are you going to do if you just happen to need parts and cannot find any. Dont waste money on fixing it. Get an engine that has parts availability.

 

[TobyU]

That could certainly be welded up but it probably has a snapped rod inside of the block. They're really not rare enough to worry about saving and it's going to cost you probably at least $125 to maybe 200 in parts just to get it back together and running.
You can buy a good used donor engine, even one you can hear run before you buy it for 100 to 200 in most areas

 

[first pull]

27 hp rare Briggs craftsman riding mower from 2005. Got it from my neighbor. Apperantly he was using it and the block cracked here and gushed out all the oil. Why did this happen? Can I just Tig weld it shut and fill it back up with oil and call it good? It's a pretty rare engine and would like to salvage it if possible

No

 

[catfish51]

I agree that motor has to be torn down first to see how bad it is hurt internally But if you then decide to repair it I would give the crack a try with one of those low temperature aluminum brazing rods that they sell on the internet. They melt at a lower tmperature than aluminum with a standard small propane torch so there would be no melting of the original block that TIG welding would do .But honestly I think internally that motor has some serious damage and I would suspect that the cylinder walls are not that good either

 

[bertsmobile1]

I agree that motor has to be torn down first to see how bad it is hurt internally But if you then decide to repair it I would give the crack a try with one of those low temperature aluminum brazing rods that they sell on the internet. They melt at a lower tmperature than aluminum with a standard small propane torch so there would be no melting of the original block that TIG welding would do .But honestly I think internally that motor has some serious damage and I would suspect that the cylinder walls are not that good either

as posted in reply # 14
They are difficult to use on a crank case and it will probably get too hot in use and the patch will slump or simply blow out
Most melt around the 300 º C mark and go mushy around 250º C
Mower crankcases are usually an Al-Si-Cu-Fe alloy , BP 401 or whatever the US equivalent it
There are a lot of different formulas for those solders so you always have to check the melting point and safe operating temperatures before using them
Extra bit
Those solders are just that solders originally designed to join fresh clean aluminium tubing in heat exchangers as found in air conditioning , fridges & freezers
They are difficult to use and require the part to e very clean before you start then to scratch through the aluminium oxide coating on the part to be joined while it is submerged under a molten blob of the solder .
Trying to do this to a rough fractured cast surface full of oil is very difficult .
In all of the demos they use it on nice clean billets that are flat & clean , not a complex 3 dimensional casting that is putrid
Electric welding of thin alloy castings is also quite difficult as you tend to blow holes
Torch welding is by far the best where you have close control over the heat in real time & can go as slow or fast as you are comfortable .
I have tried just about every rod on the market and none of them do a particularly good job & have had more then one soften & blow out of the patch.
If the little end goes then usually the engine is repairable
when the big end goes usually there will e damage to cam shaft bush as well and the block is essentially trash