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wiseco forged pistons are possibly lighter than stock pistons.
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quote from pggg
.. exactly, there is a reason that wiseco has been in business for a long time. thanx Patrickwiseco forged pistons are possibly lighter than stock pistons.
good luck Tod, i'm sure your bike will run great.Comment
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If the weisco pistons are lighter than stock pistons and the theory is that the crank is balanced to the exact weight of the rods and pistons. This would also create a balance problem?????? Cranks are not balanced to the weight of the rods and pistons. The rods and pistons can weigh what ever they want as long as they are all uniform in weight. Dynamic balance is what makes up for any change in piston/rod weight. When one piston is rounding the Top Dead Center another piston is rounding bottom dead center. This cancels out any vibrations. The reason why you balance a set of pistons is to make sure all piston weights are the same so when one piston is Rounding TDC the other piston is rounding BDC so the weight of the two pistons are pulling against each other with the same force thus canceling out any vibrations. As long as the weights are the same no virbations will be created.
Last edited by excess11; 08-27-2006, 06:32 PM.Dan ( A.K.A.- MacGyver )Comment
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Lord knows I haven't the knowledge to argue here. Doesn't anyone have a rebuttal for 'ol Macgyver??
And GNEPIG...
You may not remember how bad I screwed up a simple head swap....(The round piston thingies, and the round valve thingies seem to like their own personal space and don't seem to like actually MEETING!) I think I'll wait for MAXIMAN to offer to use his garage, tools, and beer to get it going for me! LOL. Anybody ready for that snowball fight in Hell??good luck Tod, i'm sure your bike will run great.
TodTry your hardest to be the kind of person your dog thinks you are.
You can live to be 100, as long as you give up everything that would make you want to live to be 100!
Current bikes:
'06 Suzuki DR650
*'82 XJ1100 with the 1179 kit. "Mad Maxim"
'82 XJ1100 Completely stock fixer-upper
'82 XJ1100 Bagger fixer-upper
'82 XJ1100 Motor/frame and lots of boxes of parts
'82 XJ1100 Parts bike
'81 XS1100 Special
'81 YZ250
'80 XS850 Special
'80 XR100
*Crashed/Totalled, still ownComment
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.. wow, so then what your saying is those large heavy looking cast steel deformations opposite of the big end journal are just casting imperfections on the crank and we can just cut them off?Cranks are not balanced to the weight of the rods and pistons.Comment
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Wonder why they always seem to be opposite to where the rods are attached... wow, so then what your saying is those large heavy looking cast steel deformations opposite of the big end journal are just casting imperfections on the crank and we can just cut them off?
mro
btw, no fly wheel on an XS so would imagine that some of what GNEPIG says has merit but not criticalComment
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If the pistons were lighter, couldn't you shave off the difference on the crank counterbalance? Or is there a margin in which a weight limit is acceptable. I don't really know if that would work but it seems like it would if the crank was evenly shaved. I don't see the point of going through all that trouble when the original works well.
BTW: you guys kill me! This post is suprisingly funny. Maby its the fact that it is midnight and I didn't sleep last night,United States Merchant Marine Academy, Kings Point, NY
If I can do it at 18 yrs old, anyone can
"You know something, You can't polish a turd"
"What are you rebelling against", "Well, what do you got?"
Acta Non VerbaComment
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Forgot to say that I feel an experiment coming on. I have a bunch of small RC engines to take apart. Time to get out the old scaleUnited States Merchant Marine Academy, Kings Point, NY
If I can do it at 18 yrs old, anyone can
"You know something, You can't polish a turd"
"What are you rebelling against", "Well, what do you got?"
Acta Non VerbaComment
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.. no, not critical, i've ridden the before and after and the results are quite exciting, although it didnt vibrate say like an XS650, the vibration was more noticable than stock. as i said, i would'nt do it to my every day ride.btw, no fly wheel on an XS so would imagine that some of what GNEPIG says has merit but not criticalComment
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Originally posted by GNEPIG
.. wow, so then what your saying is those large heavy looking cast steel deformations opposite of the big end journal are just casting imperfections on the crank and we can just cut them off?
I guess it is funny to make fun of things that you do not understand. Some day when you understand phisics and dynamic balace you will see that the joke is on you and you really are clueless Those large heavy looking cast steel deformations opposite of the big end journal are there to compensate for the compression stroke of the engine. This is how you get the inertia to overcome 130psi of compression. Rod and piston weight have no effect on crank balance.
Dan ( A.K.A.- MacGyver )Comment
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I just happen to have an XS thats had the crank done. Both lightened and balanced, as well as several other mods.originally posted by GNEPIG
.. no, not critical, i've ridden the before and after and the results are quite exciting, although it didnt vibrate say like an XS650, the vibration was more noticable than stock. as i said, i would'nt do it to my every day ride.
Have not ridden it enough yet to compare vibes, as have other issues dealing with first. Responds to twisting the grip "right now" tho..........
mro
to be continued.....Comment
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Crank
You can send a crank out to any good machine shop and get it balanced. They don't need to know the weight of the pistons and rods to do this. They do not regrind the lobes of a crank to make up for changes in piston or rod weight. A crank is spun balanced like the tires on your car and is not ground off balance so that when you add rods and pistons to it, it is then in balance.Dan ( A.K.A.- MacGyver )Comment
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This is probably not my department, but it is my link, so I felt that I needed to say something. One thing I love about this site is that you can get so many points of view from so many walks of life around the globe. The name of the game here is respect and decency. That is what takes this site above and beyond other trash talking bike sites. People here can and often do have difference of opinions, but they should be able to express those beliefs without being belittled or called names.
I have emailed a question to APE racing products about this, and will post back the answer I get from them. Thanks.
TodTry your hardest to be the kind of person your dog thinks you are.
You can live to be 100, as long as you give up everything that would make you want to live to be 100!
Current bikes:
'06 Suzuki DR650
*'82 XJ1100 with the 1179 kit. "Mad Maxim"
'82 XJ1100 Completely stock fixer-upper
'82 XJ1100 Bagger fixer-upper
'82 XJ1100 Motor/frame and lots of boxes of parts
'82 XJ1100 Parts bike
'81 XS1100 Special
'81 YZ250
'80 XS850 Special
'80 XR100
*Crashed/Totalled, still ownComment
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Very interesting thread. I found this article which gives a pretty good rundown on crank ballancing. There are some other good explanations out there but some get pretty technical. My opinion of the rebuild is keep it pretty much stock unless you plan on drag racing alot. These are very capable and durable engines in stock form. Unless your trying to shave a few tenths off your quarter mile time I would rather spend the money on things like paint and replating. Just my .02 Here's the link. http://www.442.com/tech/balancing.htmlOriginal owner of 1980
Midnight SpecialComment
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GNEPIG, 1
Well it is more important than I thoughtWonder why they always seem to be opposite to where the rods are attached.
mro
btw, no fly wheel on an XS so would imagine that some of what GNEPIG says has merit but not critical
for high performance in particular. Always been a fan of balancing.
mroComment
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