Crank Scrapers

[Caveman]

Geez... this is the stuff that pops into my head when I should be doing something productive...

Custom crank scrapers make extra horsepower...

Here's my question:

If they're mounted between the block and the oil pan, how is gasket relationship handled?

I can see putting RTV between the block, scraper, and oil pan on both sides, but what do you do for the end seals? I.E., the extra thickness of the scraper adds a gap on both ends... Just add more RTV?

[Caveman]

Re: Crank Scrapers





Anyone wanna be a hero?

;D

[jcharliem]

Re: Crank Scrapers

Umm. I think many are attached to the main caps. No mating between the pan and block.

[TC]

Re: Crank Scrapers

Umm. I think many are attached to the main caps. No mating between the pan and block.

He's actually talking about a scraper that mounts on the oil pan rail. It is for oil control. Look at the piece at the top of the pic that is what he's talking about.


I always wondered the same thing, what about the gasket. But common sense tells me that you'd put a thin film of RTV between the scraper and the block and then put the gasket on top of the scraper. Sounds good to me, what do you think??

[milner351]

Re: Crank Scrapers

I would think using two gaskets would be the way to go, perhaps some gray rtv on all sides just for insurance.

[min301]

Re: Crank Scrapers

Correct.
Keep in mind, scrapers are thin, still enough compression
of the end seals to not be an issue.

[JeffMcKC]

Re: Crank Scrapers

for me, they are not worth all the work to get them close enough to work right

[73fish]

Re: Crank Scrapers

I just used RTV between the block and the scraper then just put the oil pan gasket over the scraper. I have one in both of my motors with no problems.

[Caveman]

Re: Crank Scrapers

I just used RTV between the block and the scraper then just put the oil pan gasket over the scraper. I have one in both of my motors with no problems.

How much HP are scrapers worth? 1%? 2%?

Granted, folks that use 'em are probably also running knife-edged cranks, and killer windage trays... but separately, how much?

When I see posts in other threads of minivan motors with windage trays, it makes me think that there are a few engineers in Detroit that think its worth it....

IMO, I'd say that windage trays and scrapers are dollar-for-dollar worth it, but knife-edged cranks are a ton of work/balancing/$$$....

Comments?

[TC]

Re: Crank Scrapers

for me, they are not worth all the work to get them close enough to work right

I agree with Jeff on this one.

[min301]

Re: Crank Scrapers

I think it's worth it.
Anything you can do to reduce windage, and get the oil in the
sump, and away from the crank is agood thing, IMO.

[JeffMcKC]

Re: Crank Scrapers

a big shoe box pan with a screen and a kick out

[milner351]

Re: Crank Scrapers

Jeff - with the hard launching cars you've built -- what kind of pans / pick ups / windage trays have you been the happiest with?

I would think that the oil in a hard launching, tire lifting car is going to end up in the back of the pan, making baffles and pick up location important off the line.

[JeffMcKC]

Re: Crank Scrapers

The best pan I had was a moroso ultimate II but lost it in a mishap, I have a milidon now nothing special, but the thing works always good pressure launch and braking has a kick out in it. If I class raced I would be with a big stef's pan, and a scraper, I really work on the chassis more than motor stuff, when I ran a 302 I built my own with a tray in the front still lost pressure on launches. Its always been my feeling the money is better spent on chassis tuning than the motor, after a base point is set if your looking for power. If you have pressure problems a acusump is a good choice for helping also.

[LSX-GTO]

Re: Crank Scrapers

for me, they are not worth all the work to get them close enough to work right

I agree with Jeff on this one.

Not to jump on the bandwagon... but in the three NHRA Stocker projects I worked on, the removal of the crank scraper made more power on the engine dyno...

Ed