Hey, simple question:

What does it mean to weld up the mains? I was told this means welding the main caps right to the block, but I seriously doubt thats what it means...

Anyone know?

My first guess would be to weld up cracks in the mains. I don't think I have ever heard that terminology before though. I had a friend with a GNX and when we did his motor he sent the block out to have the main area filled with metal to strengthen the block. This was a while ago and I don't know if it was necessary because I haven't seen the car for a while. I'm not sure if this helps but there it is...

That's one of the ways you put a 350 crank in a 400 block, or repair a really demolished crank when a bearing eats a journal and it's an otherwise very good or hard to find crank, etc. You put it in a lathe and deposit metal onto the journal in question, which you can often put far better metal onto it than it came with; and then turn it back down to the exact size you need.

weld the mains to the block, that's pretty good. also the mains and pins might be undercut and then built up with hard chrome and then reground to size and polished. i'd guess too you might weld up one side of the journal to off set it.

So RB, do you mean you sorta weld a bead around the journals to add metal, then just machine them down to size?

That's basically it.

Cool.. thanks for clearing it up. I knew the guy that told me that was wrong