first time for this backwards top end

stuartracing

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Dec 9, 2008
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Re: different way to mount a tuned pipe

I really think this is soo cool....I would try it in a second if I had a pipe that would fit the cyl. .....I just got done with doing the piston skirt matching to the intake port....and then I run into this post.....Cool deal,way to go....
Paul....
 

misteright1_99

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Mar 21, 2008
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Treasure Coast, Florida
Re: different way to mount a tuned pipe

Have you had a chance to run the bike yet with the piston mod Paul? I did it a month ago and was very impressed with the response, and smoother run......
George.....
 

stuartracing

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Dec 9, 2008
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Re: different way to mount a tuned pipe

Not yet George just did it a few hours ago, and did it on the spare motor I have....But I heard it was a pretty good mod to do for some smoother running...I might go ahead and do it to the motor that is in my bike now....I`m really wanting to feel the difference .....Probably do it tomorrow,lol.....
Paul.....
 

dyzionyc

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Dec 19, 2008
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ny long island
Re: different way to mount a tuned pipe

nice pipes one thing that makemes me think is how you spin the cylinder around so that carb is in the front, my one is coming wid carb towards the back. maybe some one can point me in the right direction. to the right thread , with the perfromance 49cc pocket bike pipe there are two with a stright manifold and a L shaped any one tried both pipes and noticed any difference?.

thnks
 

Walter F.

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Jun 4, 2008
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Re: different way to mount a tuned pipe

Our Guru of the extraordinary Norman did it with photos start looking in his posts-Good Luck Walter F.
 

Norman

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Jan 16, 2008
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Re: different way to mount a tuned pipe

I would like to put two engines together for a side by side twin like a Yamaha bike I had back in the 70's a 100cc twin street bike and for its size it was a hot thing it would hit 90mph in good tune at least that is what the speedo was saying when it died after a good tune up a TNT speed and sport shop in West Quincy Mo. I was passing every car on hwy 136 going back to Hamilton, Ill. I could not believe how fast that bike was running.
Fond memories for me at 16 years old and still in high school.
Norman
 

misteright1_99

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Mar 21, 2008
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Re: different way to mount a tuned pipe

I would like to put two engines together for a side by side twin like a Yamaha bike I had back in the 70's a 100cc twin street bike and for its size it was a hot thing it would hit 90mph in good tune at least that is what the speedo was saying when it died after a good tune up a TNT speed and sport shop in West Quincy Mo. I was passing every car on hwy 136 going back to Hamilton, Ill. I could not believe how fast that bike was running.
Fond memories for me at 16 years old and still in high school.
Norman
Was it the RD100, Norm, like this one?????

Webshots - Full Size Photo
 

Norman

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Re: different way to mount a tuned pipe

it looked kind of like that mine was a 1968 or 69 model that one there looks to be a newer model but its close to what I had I don't remember much else it had just a speedo and no tach or turn signals.
norman
 

eDJ

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Jul 8, 2008
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Wayne National Forest
Re: different way to mount a tuned pipe

What I find interesting in this set up (without even addressing the carb) is the ease & advantage
one would have in adjusting the header pipe length between the exhaust port of the cylinder and the diffuser cone of the body of the chamber. Opposed to adjusting the length of the stinger. I understand this is where you really make significant gains in tuning a chamber's performance dynamics and it will depend on the % the header pipe is wider than what the exhaust port opening is at the cylinder. If your header pipe is 10% to 50% larger than the exhaust port....the length of the header pipe may be from 6 to 11 times that diameter. The lower length number for maximum hp and the larger for a wider overall power band. This according to my research.

As for the carb, I'm left to ponder using an "L" shaped tube to mount the carb to with the
opening facing to one side of the bike or the other. If the bike is ridden during dry warmer weather
carb heat wouldn't be necessary. When the carb is behind the cylinder as it was designed to be
it is in an environment where it can aspirate warmer air. (in cooler damp air riding icing could
occur at the carb intake) I wouldn't think a carb heater would be that difficult to set up to vent
warm air thru a small tube into the air cleaner.

Just some thoughts to consider.
 

Egor

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Jan 30, 2008
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Hurricane Utah
Re: different way to mount a tuned pipe

One of the fastest, and winning-est GP bikes in the 60's and 70's, I think from Germany used that format. It had a double loop frame so the pipe was closer to the cylinder and ran over the rear tire. Fun to see thinking outside the box. PS: Looks cool too. Have fun, Dave
 

tuf720

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Mar 22, 2009
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new zealand
Re: different way to mount a tuned pipe

hi there norman have you gone back and matched the transfer ports yet. Hows the power does it go better with the carb in front
 

NEAT TIMES

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Re: different way to mount a tuned pipe

Norman, Thats Cool. I Remember Seeing That Last Yr, But Forgot About It. I Have Acquired A Identical Exhaust, Even Has The Spring Loaded Flange. How Did It All Work Out. Are you still running it that way, did you do the cyl mods? Ron
 
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Norman

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Re: different way to mount a tuned pipe

I sold that exhaust/intake/velocity stack/ air cleaner system, I've since returned the engine to front exhaust. It worked very well and I had no over heating problems etc. Yes you can match up the ports it take a little work. Thanks guys glad you liked it.
Norman
 

Masterm222

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Feb 14, 2009
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Billings, Montana
Re: different way to mount a tuned pipe

Where can I buy an expansion chamber/kit? Sickbikes is out of stock! This is a must have item for build number 3. Just got a Giant "Stiletto" chopper and stock exhaust will not look good or even fit very well. I have a PK80 motor for this bike.
 
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Norman

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Re: different way to mount a tuned pipe

look on ebay pocket bike parts best I know or google pocket bike shops etc.
 

Echotraveler

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Aug 25, 2008
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Re: different way to mount a tuned pipe

wow great thread!!!!
so to make this possible i would just need to invert the head of the motor? thats it, then manufacture an intake and accomodate the pipe?!
 

Norman

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Re: different way to mount a tuned pipe

you can turn the head backwards it(the engine) won't know the difference.
 

Pappy

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Apr 19, 2009
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Re: different way to mount a tuned pipe

Nice job Norm,
But I was woundering. You said you had to match up the ports after you reversed, Would it have been easy'er to reverse the piston aswell ?

Im doing the mod on my OCC, just need to know what Im getting in to.
 
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