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Thread: Crank Scrapers
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post #10 of (permalink) Old 03-18-2007, 07:45 AM
Kevin Johnson
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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."

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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:
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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

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Then I wrote:
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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

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Then you wrote:

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

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Then I wrote:
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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
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Then you wrote:
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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!


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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.

Kevin Johnson is offline  
 
 
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