Kiln_Red

I'm hoping we have a BA welder on the board that can offer insights about welding on Reynolds 390.. The aluminum alloy that our engine casts are made from. I could end up with a project that would make welding on the block necessary, but don't have the knowledge of what rod or wire would be most ideal for this application. TIA!

Bigfoot928

77tony

If Joe doesn't spot this thread shoot him a pm: "Polecat702"

Kiln_Red

Kiln_Red

Noted! Thank you.

Mrmerlin

Greg Brown will know what welding material is needed as well as Joe

polecat702

You'll need to be very specific, as to what you need welded. You will never wire weld an aluminum engine block, without the base metal failing or the weld itself failing. Can't get the penetration needed. It's got to be clean, as in surgery clean, preheated jigged up to control distortion, and warpage.

I'll need a lot more information to write a comprehensive welding procedure. No run of the mill welder will be able to weld this alloy. Welding aluminum is an art in and of itself.

Here's my take based on silicon content. For a block with 7%, my first choice would be TIG Rod, 3/32 2139, 2nd choice ER4043, or Alloy 5 6061, depending on the application, and location of the base weld. This is TIG welding only. Forget wire. This rod will work for a range of 7 to 12 % silicon content in the base casting metal.

Kiln_Red

All I am looking for is the most appropriate rod for this alloy.

Pulse MIG has changed my thinking about the limits of wire feed welding. I don't know if it is an impossible solution. TIG should be better.

polecat702

I have a MIG welder that allows me to download the panel welding parameters from Ferrari, on my laptop to the welder. I'll run continuous once the panels are tac welded and clamped to prevent warpage. I bought the welder from the SEMA Show,around 12 years ago. It was $ 26,000.00 then, and I snagged it for 19K, after the show. It's a Lazar pulse, one of the first. I wouldn't try it on anything heavier than 18 gauge sheet metal, continuous, 16 max stitch welding.

What ya really need is a good Heli-Arc machine. Scratch TIG, is OK, but you need the heat control that only the pedal can give, maybe a purge box too, and proper backing gasses.

Bigfoot928

and the block will need to be heated.

GregBBRD

The engine block is made out of aluminum?

Wow! That's super cool!

Kiln_Red

EXACTLY what I was looking for.. Thank you! I have effectively used pulse MIG for replacing components of the C7 Corvette frame as that is required by the GM P-Sheets. IIRC correctly the metal at the rear frame rail ends was only 14 gauge and I did note that achieving any meaningful level of penetration required near max duty by the machine's capabilities.

It's the primary base material, so I am satisfied to call it 'aluminum'.

GregBBRD

The last one we fixed had corrosion damage at the very top of one cylinder. We ground out the corrosion...ended up pretty deep. Pre-heated and TIG welded with a special rod. Ended up perfect.
No cylinder distortion....ended up only needing to cut down the weld and surfacing the deck surface a couple of thousanths. Didn't even need to touch the bore!

EXTREME LEVEL OF SKILL REQUIRED! We took a "donor block", cut chunks out of the top of cylinders and practiced various techniques, filler rod, preheat, and shielding gas, before attempting.

I was mentally prepared to have to put an Alusil sleeve in this block.

Kiln_Red

Looking forward to the challenge.

Without a spare block, I probably wouldn't mess with it.

The Forgotten On

Would any of this apply to repairing the alternator bracket attachment points on the block?

I know the lower half is a different metal than the upper half and less finicky IIRC because of the much lower silicon content allowing a "cleaner" weld.