Somebody Got Some 'splainin' To Do!

GoldenMotor.com

jimraysr

New Member
Apr 19, 2008
78
0
0
Glendale, AZ
Now you are talking my language. Hard to pick between cornbread with hot butter and pie, but I manage to eat both.) Guess we need to get back on subject before we get sent to the root cellar for droping a case of eggs through a knot hole in the egg house floor. Jim
 

datz510

Member
May 9, 2008
290
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16
Mesa, AZ
The accessories that you got are all the same ones I got with my livefast 67cc kit. That muffler is very nice, its actually very quiet.
 

Saddletramp1200

Custom MB Buiilder
May 7, 2008
1,451
83
48
Houston, Texas
So If I understand this correctly, If you are in Texas and use a smaller spoon you can get MORE gravy out of the little plastic TV dinner tray?rotfl
Later Tramp(c)
 

jimraysr

New Member
Apr 19, 2008
78
0
0
Glendale, AZ
Pi ~ 3.14159265358789...

should've been a drive by math quiz!:ride2:
Naturally I rounded it off. Thought it was being considerate of those who have found a 14 digit decimal was of little use in the pratical world. Fortunately those who need such refinement are shut up in a world of their own and work for tenure rather than an easier life. 8O) = (big glasses, big nose, big mouth and a turkey chain) Jim
 

MrLarkins

HS Math Teacher
Jun 17, 2008
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Arkansas
Naturally I rounded it off. Thought it was being considerate of those who have found a 14 digit decimal was of little use in the pratical world. Fortunately those who need such refinement are shut up in a world of their own and work for tenure rather than an easier life. 8O) = (big glasses, big nose, big mouth and a turkey chain) Jim
so Jim, what are you REALLY trying to say about me and my friends?:D just remember, my kind stretches to your kind right here in these wonderful forums(^)

besides, my avatar is PI...and actually, I got it stickered on my MB and when school starts back up I am taking my gas tank into shop class and will have some talented art/shop student paint that avatar right there on the tank, just as it is in my avatar
 
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KilroyCD

New Member
Jul 22, 2008
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Lancaster County, PA
This thread has me thinking about this equation; "If you're paddling a canoe uphill and three wheels fall off, how many pancakes does it take to cover a dog house because cats don't eat ice cream? A; True; or All of the above?"
:eek::D
 

jimraysr

New Member
Apr 19, 2008
78
0
0
Glendale, AZ
Mr. Larkins, I am way in over my head here. I thought your logo meant that you owned a Chinese restaurant. The last trig teacher (1955) that tried to teach me something is no longer with us. Mr. Bridgewater was a very nice person for a teacher and I am sure your are as well.

Please accept my sincere apology for casting aspersions on academia. I was happy they had a high school where I was staying as it got me out of my cell for a few hours a day. ) I guess you can have your pi and eat it as well? Jim
 

ronaldoelpaso

New Member
Jun 21, 2008
3
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0
guys, here is a scenario. 2 engines, both the same stroke (40mm). one has a bore of 45mm, one 46mm. volume of first is 62.77cc, and second is 66.48cc. thats almost 4cc difference. so, first of all, who cares. second, you can measure it with a caliper and condifently calculate it and be accurate within 2 cc. third, you should be more interested in if its 70cc with a long stroke or with a short stroke, rather than the actual displacement, as a short stroke will give you a longer lasting engine because it's less stress on bearings at full operating revs.

we all know these things have torque. the trick is to gear it right so that the workload (gear ratio and net weight if bike) is most efficient. cc means very little from a 60cc to a 70cc. performance is more determined by stroke length, muffler tuning, and intake resistance.
 

Jemma Hawtrey

New Member
Dec 29, 2007
288
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Essex, UK
Long throw or long stroke engines dont have any inherant weaknesses compared to short throw or oversquare motors... the only issue mainly is that because of the stroke they are slower revving than oversquare engines

For example a villiers 2F/JDL or similar engine with a 98cc long throw design will happily get to 4000rpm and maybe manage 4500rpm - its a function of the time taken for a revolution to complete. This is because the swept volume of the cylinder is in the stroke of the cylinder not the bore

A Modern motorcycle engine of 98cc such as for example a baby ducati desmo (man, but that'd be fun on a pushbike) - can rev up to around 14000 rpm partly as a function of the oversquare design because all the swept volume is in the bore of the cylinder, not the stroke.

There is also the fact of torsional and rotational forces. As has been said before for exactly the same weight of metal a longthrow engine will be weaker because its carrying more forces due to the longer stroke. The oversquare engine can be built lighter because there is less stress on the components - lighter components mean higher available engine speeds because you can move them faster without rotational mass becoming a problem.

The advantage of a long stroke motor is Torque. All the work in these motors is done by the torque which is a function of the stroke and the rotational forces. This is why a longstroke engine tends to be a chugging, slow revving machine but will not loose power so fast on hills and inclines

The advantage of an oversquare motor is HP. They have lower torque ratings and this is why you're little GEBE sometimes needs help up hill - because once an oversquare is out of its HP powerband the motor will start to labour

Its a case of you pays your money and takes your choice really :)

Jemma xx
 

MrLarkins

HS Math Teacher
Jun 17, 2008
487
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16
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Arkansas
Mr. LarkinS, you can only get us a link to the one millionth digit. Ok I'll give a B- for your effort...........................rotflrotfl
lol:) well, i tried to post it in the forum, but there seems to be a limit 10000 on characters.:rolleyes:

and no worries...its all in good fun jim...i get harrassed all the time.
 
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