cranks cranking around

[lyonsy]

what do they use for the cryoing if its only liquid nitrogen then i have acces to at work and whould be able to cryo the crank and rods.
id say its worth doing this to valves pushrods etc as well then.

 

[lyonsy]

i rembered some posts from a few years ago on here so i did a search and found this site off Seattle Smitty http://www.metal-wear.com
so i might give the cryo a go my self with works liquid nitrogen tank.
i think ill also lighten the counter weights off a bit.
so here's a question on the big end's they have the radius then a step up around the rod.
now i belave this is there to trap the oil so you have pressure around the big end
how much of it can i take off i think i could go down to about 40"thou or 1mm above the bearing and still retain oil.
also how much should shot peening cost ?

 

[XPC66]

You thinking about bullnose and taper yonsy? Good choice, reduces drag by creating a boundary layer on the weights, but retains balance between the topend and bottom end.

 

[lyonsy]

can you elborate on the bull noise i think i miss worded what i was meaning.
on the big end off the crank where it was orginally cast and then machined for the bearing surface there is a step or ledge iam wanting to reduce this to a minium before i start drilling holes in the big end throws.
ive also read in here that you can over balance which as i take it is.
having heavyer counter weights then the piston conrod assemble needs and helps mid range to top end.
or the crank accleration.

 

[rbohm]

8) bull nosing means to round off the leading edge of the counterweight to improve its drag coefficient. knife edging is similar except that instead of a round nose, it is a knife edge. you also want to change the aerodynamics of the trailing edge also.

 

[lyonsy]

so bull nosing is basicly tear droping the crank counter weights.
is there much you can do on the big end side