Knife-Edge or Crank Scraper?

[JesseSays]

I would avoid knife edging a crank that you're using for a daily driver. They make cranks the size, shape, and mass for a damn good reason.

[Shades]

Unless you're trying to win some sort of competition, I'd buy the crank scrapper assuming its not rediculously expensive. Knife edging is REALLY high end and has VERY little benefit to anything but all out race engines. It's pretty much the LAST thing I'd do if I absolutely positively had to make the motor all out. Even the crank scrapper is pretty dubious on our motors, but if its not ungodly expensive you could try it out. Out of curiousity what all is done/being done to the motor in question?

There are too many things to list off... I'll list off the main stuff and you can read and see the rest of it here

• Carrillo Pro-A rods
• FM Wiseco 9:1 Pistons
• SPEC lightened flywheel
• SPEC Stage 2+ clutch
• UR underdrive pulley

Thats just the stuff for the bottom end.


Thanks everyone else for your input... I think I'm just gonna go with a light knife-edge on the leading edge of the crank so that it will be more areodynamic, and a crank scraper.

If anyone was wondering they're going for $49 for the metal ones, and $99 for the teflon ones. What's another $99 to my big long expensive drawn out project.

[protégébob]

Make sure you get it balanced afterward if you knife edge it.

[Shades]

Don't worry it's was gonna get done either way, especially when you throw a lightened flywheel, pulley, rods and pistons on...

[BuGS]

I was under the impression that the MBSP kept the oil from hitting the crank so that the oil cloud wouldn't form...

[JesseSays]

Can you send me money so I can do something useful with it instead?

[naprotejay]

Thanks everyone else for your input... I think I'm just gonna go with a light knife-edge on the leading edge of the crank so that it will be more areodynamic, and a crank scraper.[/FONT] [/COLOR]

FWIW, I've read of suggestions to bull-nose the leading edge/knife-edge the trailing.

[Shades]

I was under the impression that the MBSP kept the oil from hitting the crank so that the oil cloud wouldn't form...

The oil cloud is gonna form from the oil squirters in the bores... the MBSP keeps the oil from splashing in the pan, so that the oil pump pick up doesn't suck up air (air is bad for bearings).

I've decided to bullnose the leading edge myself and just polish the counter weights on the crank. Our cranks are cast with a slight bullnose on them... so all I have to do it make it more round. The machine shops around here appear to do a pretty crappy job of knife-edging as I visited a couple on the weekend and had a look at their work. So this shouldn't take much weight from the crank at all. Since I've already got a lightened flywheel, pulley, rods, and pistons... unless I'm circuit racing, I don't need the crank lightened... yet! :D

I'll post some pictures once I've finished polishing the crank.

[jacobrussell]

reworded for those who didnt understnade

i would use both crank scraper and mbsp

[jacobrussell]

how much do these cost

[jacobrussell]

After a "little" research, Idk if i like the way it bolts using the main cap bolts

[Shades]

You still drunk from last night?... you're talking to yourself and you make no sense.

You also know you can edit your own post, within a 24 hour period, so that you don't have to look like you're talking to yourself with three posts.

[MD323]

considering the amount of threads and ancient bumps I think hes trying to bring up the ol' post count

[Shades]

What does bringing the post count do for your profile?... makes you look like someone other than a noob?

[MD323]

i take post count into consideration when buy stuffs, and he does sell MS units

just a theory really