rst in breaking

iTrader: (2)

im building a zetec turbo, i have steel rods,forged pistons, im lookingto get my crank ground but am wondering if its worth having it knife edged? iv heard its ment to improve the flow of the oil? what are the advantages and dis-advantages of this? cheers

M K

iTrader: (9)

its not the flow of the oil it impoves its the cut of the crank through the oil,,,

think of it a a paddle through water, turned face on the paddle is hard to push through the water

but turned side on it cuts through easily,,,,

same principal with a crank,,, knife edge it to give less resistence when rotating through oil,

rst in breaking

iTrader: (2)

so its a worth wile thing to do?

DENNIS

i use a knife edge crank on my escort cos, it revs so clean and helps to reduce the lag of a large turbo. well worth it in my opinion...

-beefy-

iTrader: (6)

is it also possible to have it polished ??

just curious on this for my next build

surely that would help the resistance ??

M K

iTrader: (9)

i paid Ł250 to have my crank knife edged, polished, tuftrided & lightened & balanced

Rs1

iTrader: (1)

Do the zetec cranks actually do much swimming in the oil? If not then its a bit pointless knife edging it.

iggy gt4

mine is done on thecossie,well it was done when i got it .....not sure what the hell it does mind you....

Phil

iTrader: (1)

Has anyone else noticed how almost every cossie you see for sale seems to have a 'knife edged crank'

abdr500

iTrader: (1)

not many cranks swing into oil so no real need for it

the original

yeah, yet i've never seen one actually done.
surely it involves taking material away which weakens the crank?
I just run a windage tray on mine

AustenW

Can anyone recomend a good place to have this done?

GARETH T

on a cosworth,, the crank sits above the oil level,,, so a waste of time! im not sure about a zetec

AustenW

Its not for a cosworth YB and its getting done to reduce weight as its a high reving nasp motor in a light car

Turbosystems

iTrader: (5)

it has nothing to do with the oil it is to do with the air resistance

orion_crazy_carl

iTrader: (3)

maybe it cuts thru the air better,lol,sure zetecs have a metal tray between it and the sump,so it dont touch the oil?

cossiemanden

I have done this to my cranck, and it have given less resistance, the engine rev more easy now, but it have also lightened the cranck and that have helped a LOT, so i can defo recomend it.
My new rods pistons and std knife edge crank are almost 2kg lighter then standard.


(Sorry for my english, not the best description was it )

GARETH T

it is the weight or the new shape which is the gain?

AustenW

What engineering company are most compitant to do this to my steel crank?

rst in breaking

iTrader: (2)

bloody hell, i posted this 2 years ago pmsl

AustenW

Its amazing what searches can bring up

Turbo Zetec

iTrader: (1)

Damico in thetford do a few, maybe worth giving them a call. whats it on?