Crank scapers - worth it?

[Cookiemonster]

Whats everyone's opinion on crank scrapers? A valuable mod?
Or are they a myth?

[Jim]

its more than worthwhile on a race car, but a total waste of effort on a road or occassional track car.

[Cookiemonster]

What benefits will they give on a race car? Do most race engines have them?

[Jim]

yeah, all it does is help try and reduce oil mist in the crank case, by deflecting any oil that would ordinarily drop onto the spinning crank.

oil mist and oil flowing onto the rotating crank can sap a bit of power, and also prevent oil from frothing or collecting in the pan properly which can lead to loss of pressure.

[gmh265]

Originally posted by Secoh
yeah, all it does is help try and reduce oil mist in the crank case, by deflecting any oil that would ordinarily drop onto the spinning crank.

oil mist and oil flowing onto the rotating crank can sap a bit of power, and also prevent oil from frothing or collecting in the pan properly which can lead to loss of pressure.

from what i have seen, the crank scraper 'scrapes' the oil off the crank, not stop oil from dropping onto the crank.

[mopar lover]

Exactly what GMH265 has said.

One size fits all crank scrapers are ok, but the optimum is to profile it it perfectly to the crank throws.

There are some engine builders that believe a windage tray is useless. Its design by nature impedes oil return to the pan.

Apparently the bees knees is a profiled crank scraper with a deeper pan for most cars on the street.

Race cars have scrapers, kickouts, and trap doors, its all part of a package and pricey too.

[Trev]

Why are they a waste of time on a raod car?

[Jim]

*slaps forehead* quite right, I was thinking of something else

but most of what I said is still applicable anyway

[gmh265]

what were you thinking of?

[Jim]

The deflectors that fit inside the sides of the block that prevent oil from the upper motor dropping straight onto the crank.