D
Deleted member 12676
Guest
they didn't come with slant heads but I bought them just to find out the standard heads give more power due to the center location of the spark plug.
Motor Size and Power Comparison
- Thread starter Cali-Rider
- Start date
Cali-Rider
Member
I see, the only reason I am forced to use a slant head is due to my very compact frame. I did numerous other modifications for performance. I am looking for the best option for my small frame MTB with a SHIFT KIT.
Originally I built the motor to have low end torque and a wide power band since I had no shift kit. Soon I gave in to gears and got the shift kit. Since I have 8 gears I would rather a high revving high HP screamer than my old torque monster. (planning on a torque monster for my cruiser non shift kit next build)
I looked at your 48cc to 60cc conversion and it looks like a very doable option for me actually since I own some of those parts.
-You say it takes up the same space as the 48cc but has the power of a 60cc with less vibration than either?
DOES ANYONE KNOW ABOUT THE SUPER RAT???
Maybe time for a Super Rat Thread???
Originally I built the motor to have low end torque and a wide power band since I had no shift kit. Soon I gave in to gears and got the shift kit. Since I have 8 gears I would rather a high revving high HP screamer than my old torque monster. (planning on a torque monster for my cruiser non shift kit next build)
I looked at your 48cc to 60cc conversion and it looks like a very doable option for me actually since I own some of those parts.
-You say it takes up the same space as the 48cc but has the power of a 60cc with less vibration than either?
DOES ANYONE KNOW ABOUT THE SUPER RAT???
Maybe time for a Super Rat Thread???
D
Deleted member 12676
Guest
the 60cc has about the same vibration as the 48cc. Just replace the wrist pin with a lighter one. see link on my site.
Cali-Rider
Member
Yeah, I've read a ton on your site. In this thread I am trying to ask where to start from more than what I can do to modify/enhance it. I want to use the ideal base to work on and modify.
Once I get that "Ideal Motor" for my setup I will post another thread about its modifications, progress, and everything else.
So now it's
A. 49cc swapped to 60cc
B. 66cc Super Rat
Jury is still out since there has been no info on the SR.
Once I get that "Ideal Motor" for my setup I will post another thread about its modifications, progress, and everything else.
So now it's
A. 49cc swapped to 60cc
B. 66cc Super Rat
Jury is still out since there has been no info on the SR.
HeadSmess
Well-Known Member
- Local time
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- May 17, 2010
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ill say my standard old saying thing.
48cc was the best. reliability wise. vibration wise. the bigger ones were POS that die or have eternal gremlins built in
you cannot balance a 2 stroke. mucking around with weights might reduce the buzz at certain rpm, but it is NOT balanced.
no single cylinder engine can be balanced.
its to do with the fact that the pistons do NOT follow SMH(simple harmonic motion) but rather, accelerate and deaccelerate at different rates. while you might get the weights to cancel out...how do you cater for a piston thats producing more inertia at one point than at another point? you cant. not without an identical piston going the other way...
a helpful person would have said " the transfer timing on a 48 HT is approx 104 degrees, and the exhaust is approx 138 degrees"
induction was 120 from memory...been a while!
very useful figures for designing pipes.
exhaust temperature? hot! makes a poofteenth of a difference in lengths usually.
the best thing about any links mentioned? gordon jennings book on twostrokes. thats the only bit of info i found that was useful. the rest of it was....laughable
48cc was the best. reliability wise. vibration wise. the bigger ones were POS that die or have eternal gremlins built in
you cannot balance a 2 stroke. mucking around with weights might reduce the buzz at certain rpm, but it is NOT balanced.
no single cylinder engine can be balanced.
its to do with the fact that the pistons do NOT follow SMH(simple harmonic motion) but rather, accelerate and deaccelerate at different rates. while you might get the weights to cancel out...how do you cater for a piston thats producing more inertia at one point than at another point? you cant. not without an identical piston going the other way...
a helpful person would have said " the transfer timing on a 48 HT is approx 104 degrees, and the exhaust is approx 138 degrees"
induction was 120 from memory...been a while!
very useful figures for designing pipes.
exhaust temperature? hot!
makes a poofteenth of a difference in lengths usually.the best thing about any links mentioned? gordon jennings book on twostrokes. thats the only bit of info i found that was useful. the rest of it was....laughable
Automotive history is full of engines that started off small and reliable, were enlarged and tuned over the years and became unreliable; and even multi cylindered ones shook more.
The laws here on mopeds mean, when I fit my kit, I will actually need to restrict the throttle movement, which is good, because my experience is that if you don't ask what a motor can't give, it won't break.
The laws here on mopeds mean, when I fit my kit, I will actually need to restrict the throttle movement, which is good, because my experience is that if you don't ask what a motor can't give, it won't break.
