dan miller wrote:A nifty way to accomplish this is to offset grind the crank to BBC (2.200") and utilize Eagle 7.100" rods with a set of aftermarket pistons. We utilize Ross, and a call to Pat O'Neil will get you all squared away. Ross makes a beautiful and very light piston for this application. You'll end up having around $1500 in a killer rotating assembly that you can lean on as hard as you want, without any fear whatsoever.
Do the eagle rods need any mods? Are they the same journal width as 392? I see the pins are slightly different diameters. Should the pistons be fitted for BBC pins or is it better to rebush the rods for 392 pins?
I see on Eagle's website they have 3 different part numbers for the BBC 7.100 rods. Any advice there?
Am I right in figuring that the stroke will increase by the difference in journal sizes? The crank has never been ground before although there is some light scoring that might limit the effective offset, but minimally I'd guess. So that 2.375-.220=.175 3.90+.175=4.075(new stroke) If that's right, with a 4.060 bore new displacement would be about 422 CI. Did I do the math right?
It seems to me that there are 3 benefits from doing this. Stronger rod, longer rod, more displacement. If the rods don't need extensive reworking, I should consider this before I order custom pistons(the long awaited money is starting to burn a hole in my pocket!). Hell, the crank needs grinding anyway, need new pistons anyway...
I've ruled out a welded stroker but offset stroking is looking better and better to me.
Many thanks for advice.