Nissan : Datsun ZCar forum :Nissan Z Forum: 240Z to 370Z

-   Car Talk Forum (https://www.zcar.com/forum/13-car-talk-forum/)
-   -   Crank Scrapers (https://www.zcar.com/forum/13-car-talk-forum/246560-crank-scrapers.html)

Ken Hawkins 03-14-2007 10:53 AM

Crank Scrapers
 
Ran across this in case anyone is in the market

<http://www.crank-scrapers.com/prod01.html>

norm(the 12 sec dual su dude) 03-14-2007 11:05 AM

Re: Crank Scrapers
 
I installed my crank shaft scraper last year.BTW I bought it from this company.
I had to do a LOT of extra grinding over a few days with the dremel in order to get it to fit properly.
BTW if I shipped it back to the company they did offer to grind it off if I marked the areas needed for fitment, but I decided to do it myself.
I saw zero improvement in track times.It's was a complete and utter waste of my time and money, HOWEVER perhaps your own results would be different from my own.
Perhaps the owner of the company has testimonials from other L6 series owners who saw a HP increase on the Dyno or saw their track times improve after installation of their cranksahft scraper. If he does I am sure he would be willing to share those with you.



Post Edited (Mar 19, 9:56am)

1 fast Z 03-14-2007 11:28 AM

Re: Crank Scrapers
 
I run one of those exact ones in my motor, with my stroker crank. They will bolt right in with a stock crank, and you have to machine different areas for the VO7 Crank. Worth It IMHO.


jeffp 03-14-2007 12:09 PM

Re: Crank Scrapers
 
I have mixed thoughts on this part myself. Seems to me it would be best utilized in a car that will see hard cornoring. Additionally, a car running that way would also do very well with a oilpressure stabilizer tank as well.

I dont have that part on my engine, and I am not all that excited about the way inwich the part is installed. I would like to see a scraper installed to cover the whole rotating assembly, secured by dowl pins in four places, and finally sealed in between the oil pan and block. I don't like the main cap bolts used to secure the part.
The scraper dovetails right in with knife edgging the crank and all that expensive work.

Alot of work to get it right, but beneficial none the less.


Matt K 03-14-2007 12:52 PM

Re: Crank Scrapers
 
You're not going to get another 100HP with a crank scraper/windage tray, however they are proven & have dynos & engineering to back that up. Typically only good for up to ~15HP tops, so you wouldn't notice a seat of the pants difference.


frank280zx 03-15-2007 04:53 PM

Re: Crank Scrapers
 
uuuhm no they dont give HP 0 nada nothing!!!
A windage tray saves the engine under hard cornering ... not free up HP , neither does a scraper .. these are not HP items


norm(the 12 sec dual su dude) 03-15-2007 05:08 PM

Re: Crank Scrapers
 
Well Frank on some engines they do indeed add HP by stripping the crank of oil and braking up the oil roping effect but unfortuantely it didn't help mine out any.


frank280zx 03-16-2007 06:11 AM

Re: Crank Scrapers
 
Given it might ad 1 or 2 hp at most 15 is a claim i call BS on ( maybe on a full scale dragster) not on our relatively low hp engines.
Thinking of it maybe small displacement hig revving four bangers might benefit of it more ?? )

Anyway that is not the main reason to use one ..

It is faster revving, and prevent 'foaming'in the oilpan leading to starvation.. and well all disaters that follow that !


240zcar 03-16-2007 09:32 PM

Re: Crank Scrapers
 
It aint gonna do a dang thing for performance. Its strictly a braggart item.

Kevin Johnson 03-18-2007 07:45 AM

Re: Crank Scrapers
 
Norm wrote:

"I installed my crank shaft scraper last year.BTW I bought it from this company.
I had to do a LOT of extra grinding over a few days with the dremel in order to get it to fit properly.
BTW if I shipped it back to the company they did offer to grind it off if I marked the areas needed for fitment but I decided to do it myself.
I saw zero improvement in track times.It's was a complete and utter waste of my time and money."

_______________________________

Hi Norm,

I think you complained about this before in this or another forum -- hard to remember. At that time I explained that the SCCA racer who lent me the blocks did not have a diesel crank but explained that it was a popular mod.

Rather than tell people they could not have a stroker scraper (many asked when the listing went up) I moved the rod cutouts further out on the computer. I did not alter the counterweights -- some stroker cranks have altered counterweights and some do not -- this is in regards to swept path.

Thank goodness I save all my correspondence with thousands of customers -- you're remembering this a little differently.

You first wrote, in part, that, "It is hitting on journals and it looks like I will have to grind off as much as 2 mm or more to get it clear. Is this normal to have to modify them this much for proper fit?"

I replied, "If you would like, I can cut another one out for you. Just send me a pic with where you would like it reduced and by how much -- I apologize for the trouble!"

No mailing back of the scraper involved...

Then you wrote:
-----
Hey Kevin, I finally got around to adjusting the crank scraper. I had to remove a lot of material to keep the journals from hitting. I'll send pics to you later so you can see what has to be corrected for future cuts.
I had a question about the ideal distance from the counterweights to the scraper. Cylinders 3 and 4 are much closer than 1 and 6 and I wanted to know which distance is correct. I figure I can put some epoxy on 1 and 6 if the gap is too large at that point.

Thanks,Norm

-----

Then I wrote:
-----
Hi Norm,

The ideal clearance is 1mm or .040". It sounds like the counterweights on the LD28 have different ODs. The pattern has them at the same OD as on the L28.

I have attached a jpeg of the original LD28 pattern -- if you can indicate on the drawing what you would like changed that would be great.


Important: I would not recommend using epoxy. It will most likely come right off due to vibration. You can MIG or TIG weld extra metal on but the best plan is to simply have me cut you out a corrected one.

Kind regards,

Kevin

------

Then you wrote:

------
Also it required some grinding on the top of the main bolts caps in order to get the scraper to sit flush.

------

Then I wrote:
------

Hi Norm,

I see where you mean about it needing to be relieved. Yes, I have to make those reliefs for many other patterns as well.

I can adjust the mounting tabs on the main caps by just extending more of the "circle" directly under the bolts. If I come halfway down the circle would that be sufficient to clear the caps? Again, this is a fairly common mod. I guess the main caps are a little different going from the L28 to the LD28.

The Loctite is optional, I did not use it with the same style of installation on the Suzuki engine and if I recall correctly the torque on those bolts is only around 40 ftlb.

The epoxy still concerns me. I am happy to cut you out another one. Really. ;-)

Just let me know how much you would like added to the counterweight areas. I see that you have not installed a rod yet -- do you want to check that prior to me cutting a new one?

Kind regards,

Kevin
------

Then you wrote:
------

Hey Kevin, these are L28 main caps . It just barely hits on the casting flash on 4 of the caps. Its a cinch to grind off. I don't think that GRAY STUFF will come off as it is oil resistant and it's a bear to even scrape off! Also it will only be a 1.5mm small thick buildup. I don't think it's really necessary for you to have to cut out a new one, but I'll let ya know if I change my mind! If I run into any problems with the rod bolts I'll let ya know!


____________________________

So, really, the situation was that I offered to cut you a new one a number of times. I am not sure how much more a company can reasonably do.

About four weeks ago someone wrote to me that they wanted four scrapers made for a particular engine. I could not borrow one so I bought a core for $300 and spent 7 hours on a Saturday picking it up. So, at best, this was not even a break-even deal for me.

Now I hear nothing back from the other party.

I really do go out of my way to try to help people.



All times are GMT -4. The time now is 12:45 PM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.1

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.

 
For the best viewing experience please update your browser to Google Chrome