jackhammer

Look at the poor crank! I couldn't believe my eyes! I've seen cranks with 1 hole or 1 plug, but this is beyond my comprehension. The picture doesn't show the extent of the holes very well... they are different diameters at different depths. The flywheel had material removed as well.

One thing for sure, right or wrong, the guy spent a lot of time on this.

www.strokermotor.com

DES DG3-425 4340 Nitrided BB Chevy 496, Ext. Balance, 4.250" Stroke, 2.20" Crank Pin, 6.385" Min. Rod Length, 2pc Rear Seal

jackhammer

Also, everybody and their brother told me I was going to have to clearance the block. I wanted to do this before sending the block for a bore, so I just layed it up there (with some bearings and oil) and went to start marking off where to grind, and, and, and, I can't find anyplace to clear?? there's at least an eighth inch clearance here. Are these H rods that much smaller? Or am I missing something?

evelkevin

4.25" in a BBC stock block does not need to be clearanced.

1BIGJIM

iTrader: (1)

Mine did.

jackhammer

I'm guessing the "I" Beam rod with the thru bolt and nut need the clearance work. I don't have one handy to compare, but the H beam appears to be a lot smaller in that area. If so, it's good info for the next guy... either pay $ to clearance the block or pay $$ and upgrade to H beam rods. If you need longer rods anyway then it's a wash.

ghittner

Mine didn't.

jmherbert

My machine shop which does mainly does race car motors, hundreds if not thousands a year told me that some block castings need it and some don't, even from the same generation/year/etc. The only way to know for sure is to mock it up, or clearance it anywho.

vtec

jmherbert:

Who is your machine shop?

kennyo

I had to notch the block AND take about a 1/4 inch off the crank throws then have it rebalanced.

kevinr

balance man should have tried to make it a internal bal. or lathe off the counter