machining services take 2 (old thread, new info)

[rdsarefun]

I reached out to Bill Bune (Minnesota) from a recommendation on this forum and his prices seem very reasonable, Has anyone had extensive porting and or boring work done, and if so what were your thoughts?  Also any advice on using Banshee pistons in an RD with the skirt modifications needed?  Thanks, Brian

[m in sc]

very common to use banshee pistons on an rd. but there's no real benefit over other ones, or, IMHO, forged pistons vs cast unless its a full blown race motor. even then, not so much IMHO. I prefer to run the cast pro-x. my tzr runs cast pistons and it spins up to 11k no issues. over. and over again.  I have forged wisecos in my lightweight and while it runs fine it sounds like absolute shit idling.

Bill bune does great work, im more familiar with his stuff from the kaw triples.

[rdsarefun]

Hi Mark, Appreciate the quick reply.  My old engine that Chuck Q did work on  suggested I use the Pro X, he was not a fan of the Wiseco's due to the clanging and banging until they get warmed up. What "mods" need done to the skirt to use these within an RD, is their any writeup on this?

[SoCal250]

On the intake side of the piston, trim off the small tab on the bottom of the skirt below the windows. You want to cut it off so the skirt is straight across in that area. Smooth it out and then chamfer the outer edge

[m in sc]

yup^ super easy.

[rdsarefun]

Awesome, that what I was looking for.  Thank You all

[m in sc]

im going to play devils advocate here. you also can just radius the tab. I did this last time with a file.

mine and matts bike. zero issues.

[irk_miller]

IMO, the issue with cast pistons isn't so much about how they perform when everything is going great, it's how they fail.  Cast pistons tend to explode into a thousand screaming pieces while forged tend to just maul and deform.  I use them interchangeably, though.  My failures are usually bad decisions, not the style of piston I'm using.  LOL 

I learned the hard way that you really just need enough of a chamfer on the skirt to let it slide past the floor of the port when the piston swells, tab or not.