What exactly is a crank scraper and are there any significant advantages?

[Bigvinnie]

Came across this web site recently on scrapers. Just wondering if there are any advantages to purchase something custom like this for the KA.Also claim to use highly durable vibration absorbing plates, do you guy's think there is any truth to this??????http://crank-scrapers.com/prod01.html

This is supposedly there dyno proven claim on a 2.4 litre srt-4.

DYNO PROVEN *For SRT4 owners that have removed or want to remove their balance shafts When you remove the balance shaft assembly from the SRT4 (or other 2.4's) you end up with an oil pan that is a bath tub that allows the oil to move all around and cause large windage losses. The stock oil pan is actually a quality piece -- cast aluminum -- it just needs some oil control hardware.

We make a dual-windage tray (Patent Pending) with louvers and lower baffles with swinging doors. It attaches to a modified crank scraper (steel or Teflon) framework that has bridges across the crankcase. The dual-windage tray has a top louvered section that can be adjusted to closely follow the rotating assembly. Underneath this louvered tray is a second larger tray with offset drain holes. The trays are separated by a gap of 4.5mm. These drainage holes and gap allow the top louvers to quickly direct the oil out of the path of the rotating assembly. Conversely they also help to isolate the rotating assembly from splashing sump oil that would otherwise come through the louvers.

Another advanced feature are the four attachment baffles that hold the windage tray assembly to the scraper frame. These are solid plates that help to segregate the piston bays. Why? When one area of the crank has a high concentration of oil in the windage cloud the crank acts like a propeller and distributes this oil along its length. By closing this path off the oil cloud is instead focused into the tray louvers and of course the crank scraper. You can see this type of feature in the Ford Zetec sump and other racing engines.

We also make a special washer that covers the oil feed line to the balance shaft assembly. You need to block this hole when you remove the balance shafts. This comes with the kit, of course.

Yes, the SRT4 came with a scraper from the factory. The picture below illustrates it on top of our Teflon insert so that you can compare the degree of rotating assembly coverage. There really is no comparison.

[DjPantsSpecR]

hmmm, well you already know that is going to reduce a little bit of rotational loss, i know you're a smart guy so im not trying to insult your intelligence

so, for this SRT4 i think the most gains might be from removing the balance shafts, no one should have balance shafts on a race or high power application anyways

but i'm with you on this one, how much power could this possibly make? 1-2, 3-4 hp? maybe more if it causes more of a "knife edging effect," no idea? if youre splitting hairs, or building a ridiculous N/A motor i think it would behoove you to have this setup, especially for its baffels for the pan

is this an alternative to knife-edging?

[Bigvinnie]

is this an alternative to knife-edging?

Bingo!!!! That is what I was trying to get at would it be worth it for the 49.99 that they offer it for... I need to replace my oil pan gasket right now anyways so should I spend the extra money and buy something that possibly doesn't do anything at all.Here is the pic for the KA one, would it be a wise investment?

[DjPantsSpecR]

dude, for 50 bones im about to make one... wait i'd jsut mess it up

i dont think its really worth it without a baffeled oil pan with the louvers... but for 50 bucks...

i dont think you're gonna feel any power gains, but you can brag to your friends you got a crank scraper, so for 50 bones i vote yes

[Bigvinnie]

i dont think its really worth it without a baffeled oil pan with the louvers... but for 50 bucks...

This company makes baffled oil pans also.I would rather have them do it since they claim they know what there doing. I don't know how oil flows in a baffled pan. I do know that Morrosso sells a doit yourself baffle conversion for almost any make/model oil pan.

[DjPantsSpecR]

oh yeah baffles really arent that hard to lay down, you're just trying to slow the oil, or not slow, but rather restrict the oil from sloshing. side to side baffles for turning Gs and front to back for accel/decel

it would be interesting to note how much of the oil pan is full to see if the counterweights even really contact the oil.

but we're talking in fractions of a pound of oil here...

this isnt entirely credible, but ive recently read that every 1 lb you subtract from the rotating assembly is worth about 2.7 ponies...

but by those standards a fidanza would make 27 horsepower

so the ratio has to be off somewhere, so i'm saying this might be a .3 hp gain...

[Bigvinnie]

oh yeah baffles really arent that hard to lay down, you're just trying to slow the oil, or not slow, but rather restrict the oil from sloshing. side to side baffles for turning Gs and front to back for accel/decel

it would be interesting to note how much of the oil pan is full to see if the counterweights even really contact the oil.

but we're talking in fractions of a pound of oil here...

this isnt entirely credible, but ive recently read that every 1 lb you subtract from the rotating assembly is worth about 2.7 ponies...

but by those standards a fidanza would make 27 horsepower

so the ratio has to be off somewhere, so i'm saying this might be a .3 hp gain...

Yeah but if the baffles aren't incorporated properlly (ghetto rig) then the the oil sump itself cant draw oil consistently.

Although when dropping weight from the crank for knife edging, most shops shave an avg. of 3lb.s. halfweighted cranks in general produce more low end torque than HP any way's. I don't think you can look at the fidanza flywheel as a means of making that kind of power (2.7HP per lb.), after all it is more of the drive train assembly, rather than the crank assembly. Dropping weight from the crank shaft actually decreases mass, which would also make less internal resistance from flinging oil, or just a rise in pressure created in the crank case from higher rpm's. It makes more sence if that 2.7HP per LB. came internally, there is just more rotational stresses (bearings,rods,pistons and even oil). Knife edging IMO is much more efficient than the fidanza flywheel, it is just a matter of cost when you get a crank knifed and balanced. This is why I also asked the question if it would make any difference to get the scrapers, i just don't think it would do anything significant. Are baffles even really that needed for an engine that makes peak power at 5960RPM?

I'm also on a quest to get SCAT to produce a fullycounterweighed crank for the KA, myself and forum members at club 240 are trying to get a few produced.

[Kevin Johnson]

Hi,

Your discussion came up on my referrer logs.

The reason we make scrapers for the KA is that numerous KA owners asked us to for about three years. [Sort of like the quest to get Scat to make a fully counterweighted crank, I guess.]

The dyno tests referred to below were independently performed by Ed Peters on a 2.4 liter engine with the balance shafts removed. Ed gives tech lectures on the SCCA and NASA circuits so you could ask him directly about his tests. The results themselves are posted first thing on the website.

Kind regards,

Kevin JohnsonIshihara-Johnson Crank Scrapers

Came across this web site recently on scrapers. Just wondering if there are any advantages to purchase something custom like this for the KA.Also claim to use highly durable vibration absorbing plates, do you guy's think there is any truth to this??????http://crank-scrapers.com/prod01.html

This is supposedly there dyno proven claim on a 2.4 litre srt-4.

DYNO PROVEN *For SRT4 owners that have removed or want to remove their balance shafts When you remove the balance shaft assembly from the SRT4 (or other 2.4's) you end up with an oil pan that is a bath tub that allows the oil to move all around and cause large windage losses. The stock oil pan is actually a quality piece -- cast aluminum -- it just needs some oil control hardware.

We make a dual-windage tray (Patent Pending) with louvers and lower baffles with swinging doors. It attaches to a modified crank scraper (steel or Teflon) framework that has bridges across the crankcase. The dual-windage tray has a top louvered section that can be adjusted to closely follow the rotating assembly. Underneath this louvered tray is a second larger tray with offset drain holes. The trays are separated by a gap of 4.5mm. These drainage holes and gap allow the top louvers to quickly direct the oil out of the path of the rotating assembly. Conversely they also help to isolate the rotating assembly from splashing sump oil that would otherwise come through the louvers.

Another advanced feature are the four attachment baffles that hold the windage tray assembly to the scraper frame. These are solid plates that help to segregate the piston bays. Why? When one area of the crank has a high concentration of oil in the windage cloud the crank acts like a propeller and distributes this oil along its length. By closing this path off the oil cloud is instead focused into the tray louvers and of course the crank scraper. You can see this type of feature in the Ford Zetec sump and other racing engines.

We also make a special washer that covers the oil feed line to the balance shaft assembly. You need to block this hole when you remove the balance shafts. This comes with the kit, of course.

Yes, the SRT4 came with a scraper from the factory. The picture below illustrates it on top of our Teflon insert so that you can compare the degree of rotating assembly coverage. There really is no comparison.

[Kevin Johnson]

We also make numerous scrapers for knife-edged cranks -- we just add extra metal so you are able to follow the modified contours. We don't charge extra for that either.

Here is a pic of a Nissan engine that Paul Neal (SCCA Datsun 510) lent to us with a knife-edged crank and scraper:

Bingo!!!! That is what I was trying to get at would it be worth it for the 49.99 that they offer it for... I need to replace my oil pan gasket right now anyways so should I spend the extra money and buy something that possibly doesn't do anything at all.Here is the pic for the KA one, would it be a wise investment?

[Kevin Johnson]

Same concerns with the V6 group below. Here is a recent thread:

http://www.v6z24.com/jbodyforu...raper

unknownz24:"yuppers, it's a great item. I definately felt a difference in how quickly it revs, and pulls a little further into the rpm band."

dude, for 50 bones im about to make one... wait i'd jsut mess it up

i dont think its really worth it without a baffeled oil pan with the louvers... but for 50 bucks...

i dont think you're gonna feel any power gains, but you can brag to your friends you got a crank scraper, so for 50 bones i vote yes

[Bigvinnie]

Thanks for the info Kevin, it gives a little more first hand experience on the product which is what I was looking for. How much would you charge to make a baffled pan for the KA, and in your opinion is it worth it? I noticed you don't have one for Datsun/Nissan, but you make some other custom ones for other make and model vehicles.

[Kevin Johnson]

Thanks for the info Kevin, it gives a little more first hand experience on the product which is what I was looking for. How much would you charge to make a baffled pan for the KA, and in your opinion is it worth it? I noticed you don't have one for Datsun/Nissan, but you make some other custom ones for other make and model vehicles.

I do plan on making a windage tray for the KA -- it is complicated because there is more than one version of main bearing caps, never mind the different pans. There are a couple engines in front of it that I am currently doing setups for, then I will be able to work on it. I am not sure what I would charge because I am not sure what is possible/practical. The other setup prices I have now are typical, though.

[deviousKA]

These crankscrapers are excellent. Very smart and affordable way to reduce windage. I have 3 Ishihara-Johnson L series scrapers, all in use.

Kevin, I had the first l20 scraper for knife edge crank, worked out great! Your new teflon scraper, for L/Z, on my list.

[Bigvinnie]

I do plan on making a windage tray for the KA -- it is complicated because there is more than one version of main bearing caps, never mind the different pans. There are a couple engines in front of it that I am currently doing setups for, then I will be able to work on it. I am not sure what I would charge because I am not sure what is possible/practical. The other setup prices I have now are typical, though.

I understand the main bearing caps, I believe there are a total of 4 different versions z20 uses really small main bearing's (same as the L20B),then you have the z22/24 version in main bearing's, then there is the KA24e uses slightly larger main bearings than the z22/24, then there was the completly redesigned main bearing cap for the KA24de(that one looks as if it would be the hardest to design, Good luck). I will be picking up one of your scrapers after I'm done with my christamas shopping......