Technoweld on an alu engine block?

[205alive]

I've got a 1 1/2" crack on my engine block which is aluminium. I've had a quote of 'about £50' to get it welded. Anyone had any success in using Technoweld or Durafix on something like this, or will it be practically impossible to get the area up to temperature?

[Pumaracing]

The time consuming bit is grinding the crack out and cleaning everything ready for welding. If you can do this yourself I would have thought someone could TIG it up for a few beer tokens if you phone around. It would only be a 10 minute job.

[stevieturbo]

More importantly. Where is the crack ?

The block could simply be scrap.

[tinker-27]

to weld ally well its needs to be very clean, so if its into a oil way its tricky but remember it will expand and contract every time so weld is the only way ,

[205alive]

Right, here's a few pics. The crack's on the front at the bottom immediately above the sump, to the right or the oil filter and left of an oil way. Pretty easily accessible but will the sump have to come off?

[Pumaracing]

That's engine rebuild time if you weld it. The block would have to be welded inside and out and across the bottom of the sump flange which would then have to be filed flat again. Might be easier to find a new block or engine. They're not exactly thin on the ground for the 1.9 205. Try a Peugeot forum.

[stevieturbo]

How on earth would that crack there ? Is it definitely a crack right through ?

And why is there a big spacer between the block and the sump ?

[CDP]

stevieturbo said:

How on earth would that crack there ? Is it definitely a crack right through ?

And why is there a big spacer between the block and the sump ?

There's a flange for a bolt there. Maybe it was overtightened followed by repeated heating and cooling with the different materials at different rates?

[Pumaracing]

stevieturbo said:

How on earth would that crack there ? Is it definitely a crack right through ?

And why is there a big spacer between the block and the sump ?

Because it's a 1.9 engine not a 1.6 which is why I said 1.9 in my previous post because only the 1.9 engines have the aluminium spacer to accomodate the longer stroke crank. Know your engine.

[205alive]

Pumaracing said:

That's engine rebuild time if you weld it. The block would have to be welded inside and out and across the bottom of the sump flange which would then have to be filed flat again. Might be easier to find a new block or engine. They're not exactly thin on the ground for the 1.9 205. Try a Peugeot forum.

Thanks for the pointers. Definitely not going down the rebuild/new block/new engine route for now. If it can't be welded successfully without that I'll just have to get used to using a litre or two evey few weeks. Ta anyway.

[205alive]

stevieturbo said:

How on earth would that crack there ? Is it definitely a crack right through ?

Don't know how the crack got there but it does leak slightly as the engine runs so yes, it's cracked right through.

[tinker-27]

if you need a "bodge repair" try araldite it is suprising what it will fix, but it must be clean !!

[205alive]

tinker-27 said:

if you need a "bodge repair" try araldite it is suprising what it will fix, but it must be clean !!

Okay, thanks for the suggestion (I like the cheaper alternatives!). Tried some chemical metal but felt like it went off too quickly and I couldn't build up coverage properly. Like the sound of araldite a lot actually.

[AtticusFinch]

I used resin from a glass fibre pack for an emergency sump repair once after I hit a rock............... A couple of years later I thought I would make a proper repair. could I get the resin off could I buggery completley solid so left it.

[stevieturbo]

The key to any add on adhesive fix, will be ensuring it is totally spotless first. Otherwise the adhesive is never going to stick properly.

Chemical metal, JB Weld, Araldite, whatever

[Pumaracing]

I can't see a lot of oil getting through a crack that small although I've never seen a 205 block crack there. I'm wondering if a previous rebuild was cocked up somehow. I'd try cleaning it up with white spirit and smearing a bead of silicone sealant down it first. Let it cure for 24 hours and it should stick like snot to a blanket.

If that doesn't work then grind it out a bit and araldite it.

[stevieturbo]

Pumaracing said:

Because it's a 1.9 engine not a 1.6 which is why I said 1.9 in my previous post because only the 1.9 engines have the aluminium spacer to accomodate the longer stroke crank. Know your engine.

Ive been fortunate enough to avoid french ste I dont want to know them !!

[Mr2Mike]

Get some brake cleaner and a toothbrush on it to ensure it's completely free of oil and grease. Araldite/JB Weld etc should work ok, or you even better can get a metal loaded epoxy putty from many motor factors that comes in a solid lump; you break a bit off and knead it with your fingers to mix the hardener and then press it into place. It doesn't run or sag like normal epoxy can so is useful for vertical surfaces.

[NTEL]

As an alternative to aroldite, try titanium putty. I've used it to repair many steam heat exchangers and it has never failed yet. As Puma says though, grind a bit out first and then fill it.

[blitzracing]

Im with the JB weld, and clean it with cellulose thinners first.