I get a call from Falicon today: they FINALLY have my crank done. Total cost $600+. For those that have not been following this, that is $600 to rebuild a NEW crank. So what did I get for $600? Improved oiling(?), dynamic balancing, welded pins, micro polish, truing, magnaflux, and hopefully some more stuff I'm clueless about. So now I have about $1,400 into this crank!
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james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

how long did it take?

I would take some pictures if I were you so you can show people and tell them how trick it is, else you cant normally see it! Post them here too...
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NSRless again...

You wanna see trick?

This is trick


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If I have to take the carbs off once more...

They had the crank for about two months (or more), but it probably only took a couple days to do the actual work. I suspect that most of what they did is not even visible.
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james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

StephenRC45 wrote:You wanna see trick?

This is trick
]

What's so trick?
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james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

Thats a very rare HRC crank in a very rare set of HRC crank cases

Thats the only picture I'm going to post though lol
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If I have to take the carbs off once more...

I can see that there's some horses missing from that set of very rare HRC F3 crank cases.

Yeah I know Matt, but I dont like resin and I dont want to get in there cutting bits out of such a nice set of cases. Maybe I need to build another motor.
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If I have to take the carbs off once more...

Well Steve, we can discuss it over juice, but I definitely think you need to build another motor. Can never have too many.

I do have to say though that peeking into F3 cases, with that rather cheeky F3 crank, is just bliss. Much more satisfying than looking at those normal, rusty old standard cranks. "Trick", just doesn't really do it justice.

You could use that bottom end as a handy doorstop and it'd still look fast

Is that crank knife edged?
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

No, they are not knife edged. I think knife edging for power is just an old wives tale that doesnt really do anything.

It does have steel caps around it, though, which I believe take up crank case volume without the added weight of a solid cast unit.

Heck, I could be totally off track, though...
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Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
MY BIKE PICS

I'm guessing you really can't knife edge a two stroke crank. I know it does would well on four strokes though.

How much clearance do you need between the throws and the case?
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

Knife edging an NSR crank would lose crank inertia, which might make it sound good on the stand, but it might make it slower down the chute. It would also increase case (free) volume, so would reduce pumping efficiency.

Some HRC kit cranks (RS250 for example) are made from tungsten and although they are smaller in diameter than the standard crank, they weight more and have a higher inertia. The smaller crank much be used with kit cases, which have a smaller crank case housing. All this help reduce case volume to hit the right ratio.

If the crank is well trued, and has the perfect balance factor, then you can run less than 1mm clearance without touching.

On RS125's in Japan we were skimming the OD of the crank and bushing the cases for less than 1mm clearance, with no touching.

The lighter crank went very well at short, point and squirt tracks, but a stock crank with bushed cases was the choice at the fast tracks.

Thanks Matt - that helps. I think the knife edging would hurt the pumping effeciancy and render the crank useless. What about polishing though?
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

Polishing is for the dining room table.

Polishing cranks, rods etc is to remove stress raisers. Rods especially should then be blasted to put the surface into compression.

Get in there and polish the cases to remove all bumps and bruises, but then go over it with an emery wheel (or something) to roughen the surface.