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Post by phssthpok on Dec 29, 2013 10:27:55 GMT -5
...so (bleep)ing hard to find an exploded view of a 150cc GY6 crankshaft assembly? I can find pictures of the entire crank/rod/main bearings assembly, and of just the connecting rod (as a 'package' including rod, bearing and rod journal), but nothing on how the whole crank/rod/main bearings assembly is put together.  |
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Why is it...
by: jjoshua20213 - Dec 29, 2013 11:22:12 GMT -5
Post by jjoshua20213 on Dec 29, 2013 11:22:12 GMT -5
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Post by phssthpok on Dec 29, 2013 12:59:22 GMT -5
Not really. Here's what I'm talking about; This is a photo of the rod/bearing/journal parts  As you can see the rod has no 'traditional' end cap, and the journal is not an integral part of the crankshaft, which tells me that the two sides of the crank (with the counter weights and the output shafts) must be assembled onto the rod journal somehow. Here are two photos of the crank/rod assembly...one from each side   You can see the ends of the rod journal in each view, but I cannot find any information as to precisely HOW they are assembled into the complete unit. I can find all sorts of diagrams and photos of completely assembled units (like what you linked to), but nothing like an 'exploded view' showing all the parts, but *not* assembled.  |
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Why is it...
by: jjoshua20213 - Dec 29, 2013 13:14:59 GMT -5
Post by jjoshua20213 on Dec 29, 2013 13:14:59 GMT -5
I wish I could help, but your speaking past my current knowledge. I'm not quite there yet. Sorry
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Post by pmatulew on Dec 30, 2013 19:04:48 GMT -5
Shop day!
Assembling a crank is a process that requires special tools and a certain degree of skill. Generally it's a job better left to machine shops or racing shops that are likely to do rebuilds on a regular basis. So normally you would just buy a complete assembly anyway.
Getting it apart and back together is one thing. (start at around 2:00) -->
Then you have to make sure it's straight -->
Watching this guy work makes me wonder how far out a mail order crank might be after bashing around in a shipping container for six weeks...
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Why is it...
by: millsc - Dec 30, 2013 19:16:27 GMT -5
via mobile
Post by millsc on Dec 30, 2013 19:16:27 GMT -5
Buy one already assembled and swap it too much trouble to try to replace pieces of it
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Why is it...
by: millsc - Dec 30, 2013 19:20:42 GMT -5
via mobile
Post by millsc on Dec 30, 2013 19:20:42 GMT -5
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Sophomore Rider
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Post by phssthpok on Dec 30, 2013 20:48:47 GMT -5
Shop day!...(snip)...Watching this guy work makes me wonder how far out a mail order crank might be after bashing around in a shipping container for six weeks... So it's pressed together with no other parts involved....Hrrmmm...I suspected as much, but I wasn't sure. I had in fact found information similar to what you linked, but was holding out for a 150ccGY6 specific set of data, though I suppose basic information carries over from one make/model to another. Buy one already assembled and swap it too much trouble to try to replace pieces of it This isn't a matter or repairing a faulty unit. Every once in a while my mind goes off on a tangent and tries to figure out how to engineer something. In this instance, I wanted to know how the crank was assembled because I was pondering how hard it would be to make a 'boxer' (or maybe even a radial) engine out of gy6 parts. Obviously a new crank case would have to be engineered, since the 'off-side' cylinder would occupy the space normally taken up by the rear wheel, but then I had a different application in mind anyway, so it might be possible to simply 'cut off' the structure going back from the variator to the clutch/rear axle assembly. Maybe...I haven't looked at what's involved in the back part of the stock crank case yet. |
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Post by pmatulew on Dec 31, 2013 23:23:01 GMT -5
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Post by phssthpok on Jan 1, 2014 9:58:18 GMT -5
Huh. A parallel twin, 2 cycle engine. Not what I had in mind, but interesting none the less. I bet that thing makes insane power for it's package size. I had thought of that, but really I wanted to avoid the rocking and vibrations of a quick 'one-two' double thump of power strokes inherent in alternating twin, four cycle engines whether they be flat, V, or parallel (and yes, I'm aware of a few mfg's. who make parallel twins where both pistons move in tandem (Honda Rebel 250?  ), but the cranks require LOADS of counterweight, as well as additional counter shafts to eliminate the inherent vibrations issues, and weight is a major factor in my plans). In a boxer engine both pistons share the same stroke direction relative to the crankshaft and each one counters the inertial mass of the other one throughout the cycle, which inherently smooths out the operational vibrations, not to mention it simplifies the ignition system since, like the GY6, it can fire both cylinders off the flywheel on every TDC...no distributor needed.  Um, yeah...no.  Triumph already makes an inline triple, but it's water cooled, and..well...to be honest I'm not looking for a physically large overall engine size. I realize BMW already makes an air cooled boxer, but again...it's larger (both physically and in displacement) than I had in mind. Somewhere between 300 and 400cc in a lightweight, air cooled, four-stroke boxer is what I'm after. (I'd really be in heaven if I could make it Diesel...but OY VEY!...the engineering!  ) |
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Post by nulldevice on Jan 2, 2014 18:26:12 GMT -5
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