Line honing crank journals
Math is not my strongest suit but.. Using the drawing & estimating lengths to indicate the trend...
A = distance from crank CL to cam CL: 7.000"
B = distance from cam CL to chain CL (call it the radius of the cam gear): 2.750"
A^2 + B^2 = C^2
49.00 + 7.5625 = 56.5625
Take square root = 7.5208
Change A to 6.998:
48.972 + 7.5625 = 56.5345
Take square root = 7.5189 Difference of .00185. And that's if they screw up and the crank CL moves .002". Short chains are really intended for reusing damaged blocks where one or more of the main bores needs to be repaired due to damage (bearing spun in saddle, etc). That can really move the centerline.
Yep, 7.000" CCL/CMCL OR SO lmao stock "A" block tolerances float around like a bb in a coffee can.
With the ? factory ? constant of the production 2.750" radius cam gear pitch & same for the crank gear...
Point is 'bearing' speed of the chain v/s torsional wind up of the cam is inconsequential
on a street build.
Maybe + or - 3/4 deg timing change at 3k rpm (total 1.5 deg).
Now on a 'balls out artificial atmosphere build' 1.5 deg is to much...
Crap, I am rambling again, Apologies Honored Posters, Back on topic :D
harrisonm
Great Topic, thx added, to reiterate, yes the center lines will move,
on a stock build not an issue... ahahahahaha, there was this 'ol' limerick... < 2(.002) no harm on You,
3-5 (.003-.005) no worries live, 5-7 (.005-.007) running for heaven, over 7 (.007) Find a Machinist,
not a Priest...
I'm out Folks My 'little grey cells' hurt
P.s,
Always A Pleasure Honored Posters, I consider Myself ---way down on the food chain---
compared to Ya'll.
