crank scrapers- anything in it

[oldcorollas]

http://www.eng-tips.com/viewthread.c...107164&page=42

Most Engines since the 1980's have the Oil level below the Crankshaft's rotation and since the 1990's have baffles to contain the Oil there during cornering, accel and deccel.

but.... oil has to come down from the pistons and from the head.... and go past a spinning crankshaft to do so.

you would not likely do it to gain teh powah, but as an oil control measure. and sure, it is hard to measure gains in terms of oil control, but why not do it?

do you have any proof of crankscrapers causing piston pin oiling failure?

[abently]

How much does a drop of Oil weigh ?

How much affect is it going to have on a spinning 15+Kg Crankshaft ?

Laws of Physics say negligible.

[oldcorollas]

you're missing the point
but, 500grams of oil whipped in a frothy frenzy around the crank.....

the point is, you are trying to help the oil.. not help the crank....

[ed]

How much affect is it going to have on a spinning 15+Kg Crankshaft ?

Laws of Physics say negligible.

i whole heartedly disagree, and can cite engines before and after crank craper/windage control installation netting around 15hp on a 500hp engine

[ed]

Laws of Physics say negligible.

may i also direct your school of physics to the effect of a few poofteenths of a kg worth of air, a simple gas, getting in the way of a 2ton car hurtling down the freeway at 120km/h

[Esteban]

Air isnt a simple gas, Its a simple mixture of gases

[abently]

http://www.eng-tips.com/viewthread.c...107164&page=42

I'm not going to bother respond to anyone who hasn't themselves bothered to read the above link.

[ed]

wow, my first outlay of neg rep for being obstructive and annoying... congrats abently

youve only had 1 thing to say in this thread and its questionable at best wihout any kind of clarification, the 'shrugging' ongoing (and plainly annoying) commentry notwithstanding...

if you have a point, please MAKE IT and stop shirking around being obstructive referencing things without any indication as to what your point is?

[oldcorollas]

I'm not going to bother respond to anyone who hasn't themselves bothered to read the above link.

hmm i read that again and i still don't see why you linked it? it has nothing bad to say about scrapers (except one guy)

did you link the wrong thread?

[ed]

stuff ive collected at my other site on this topic...

first up:
http://www.rehermorrison.com/techTalk/21.htm

i personally like this quote, it puts crankcase conditions into perspective, allowing other things to be taken into consideration...

'A piston displaces an equal volume of air both above and below itself with every crankshaft revolution. For example, a 632-cubic-inch big-block running at 8,000 rpm moves more than 2,900 cubic feet of air per minute inside its crankcase. As one piston moves downward in its cylinder, another moves upward, so the total volume inside the crankcase and oil pan remains constant - but this rapid movement of air from side to side and front to back, combined with the rapidly spinning crankshaft assemble, creates a hurricane of incredible intensity inside the engine"

and now... some pretty pics of a worked over 928s



These are pictures while the engine is running. The picture on the left is at high rpm while the car is moving in a straight line. The picture on the right is during a high speed, high rpm left turn. The engine is fitted with a GTS sump baffle and Accusump. The oil is Redline 20W 50.

[The Witzl]

lovely reply Eddie. + for you.

I'm just going to re-itterate what a couple of people have said already:
The smallport (and maybe bigport as well) 4A-GE has a factory windage tray with crank scrapers on it, and piston oil squirters.

Unless i was in a hardcore racing situation, i wouldnt be bothered trying to improve on an already decent setup.

[Mr Revhead]

i do suggest some mods to increase capacity thought, especially if its a black top

[takai]

Yeah, the capacity hurts, but thats about it.

[abently]

wow, my first outlay of neg rep for being obstructive and annoying... congrats abently

youve only had 1 thing to say in this thread and its questionable at best wihout any kind of clarification, the 'shrugging' ongoing (and plainly annoying) commentry notwithstanding...

if you have a point, please MAKE IT and stop shirking around being obstructive referencing things without any indication as to what your point is?

I said it before and I'll say it again, the only thing I care about is the truth, not my reputation.

Yes, crankcase pressure is the real issue at hand here, but lets use some logical sense. It takes about one litre (approx) of Oil a sump Full of oil to dip to/below the min Oil level.... so assuming the worst case scenario, your corner the vehicle and this 1 litre of Oil is supposedly swept up by this hurricane (lol), the Engine would be toast within 50,000K's.

So do the maths, weight of 1L of Oil (Note SBC/BBC Pro Engines run 70W Oil anyway), weight of Crankshaft, Crankshaft inertia via stroke & Rpm, and you will easily see why they barely gain 30Hp from 800+Hp setups.

Sorry, but there are better bang-for-buck/time mods you can do then making a Crank scrapper with less then 3mm gap, not including the fact that you'ld still need to deburr the Crankshaft precisely or go through 10 prototypes before you get it perfect............

[The Real Roadrunner]

I said it before and I'll say it again, the only thing I care about is the truth, not my reputation.
Sorry, but there are better bang-for-buck/time mods you can do then making a Crank scrapper with less then 3mm gap, not including the fact that you'ld still need to deburr the Crankshaft precisely or go through 10 prototypes before you get it perfect............

that is like saying dry sumps are a waste of time

sam is talking about buying an off the shelf one so there isnt much time involved and if thats the case it may be worthwhile if he wants to rev his engine harder than the factory intended.
hes also building this engine so it wont be hard for him to do the prepwork involved.

instead of going on with useless banter and disagreeing with everyone how bout you learn about things b4 saying stupid shite.