con rod wrist pin bore

[phongshader]

I'm looking at some Nascar 6.125" con rods but the wrist pin bore is too small for the pistons I want to use. The pin bore is 0.787" but the pin dia is 0.866"...would boring out the rod pin bore to accommodate a 0.866" wrist pin weaken the rod too much, advisable? Floating pins, by the way.

[mgb260]

Depends on how big the top end of rod is. .048 bigger all around. EDIT: .0395

[phongshader]

I don't have the rods so I don'y know the answer on how big the top end of rod is. ".048 bigger all around"  means what? The pin diameter difference is .079 larger...

[mgb260]

Divide by 2 for each side. Should be .0395 each side or all around if centered.

I don't know where the .048 came from.

[ag1234]

Many engines using floating pins, steel on steel. Must lube the pin adequately. When you say weakening, meaning tension ?
   To answer that, look at LS7 titanium rod.

[DiDueColpi]

Depends upon the rod.
Lots of the Carrillo's have a relief around the big end and probably wouldn't tolerate that much of an overbore.
I would hunt down some Pankl's with the 0.827" pin bore and ream them out. They appear to have the beefiest small end. So a 0.039" overbore should be just fine.
On the other hand, depending upon what you're building, the LS rod might be a better choice. They are strong, cheap and have the 2.100" big end bore that you probably need. The small end is 0.927" so a bushing is safe and easy.

Live like you mean it
Fred