So while doing some net searching I came upon this thread: http://www.bikechatforums.../viewtopic.php?p=2331387 and found this bit of information of interest:
"The C70 cylinder head has bigger valves and a hotter cam than the C90 one. You are in posession of the "Holy grail" of Honda Cub cylinder heads. If one were to want to "tune" a C90, fitting a C70 head would be a good first step.
As I recall, a C90 barrel and piston ought to fit.
Oddly, the sky's the limit with tuning that particular engine. Depends how much work you want to put in and how much money you have. The basic engine is the same as they use in (proper) monkey bikes so there is a large aftermarket spares/accessories availability.
The 110cc conversion is popular (you need to TOTALLY strip the engine so the crankcases can be machined out bigger to take the larger barrel). You can have race cranks, hotter cams, nitrous kits, DOHC cylinder heads. You name it, it's out there. They can be made to do in excess of 100mph if you have the funds and expertise.
My two suggestions are not to do with tuning though. If it's for a field bike, look into fitting an MTX125 front end and check the frame has been welded up where it joins the rear mudguard (under the back edge of the seat, look up under the mudguard with a torch). May already have been done, but they can break in half otherwise when abused (it's just pressed together as standard)."
I didn't find anyone talking about head swaps on this board so i was curious to get some more input. I found a video on youtube of a "fast honda cub" that has a "wave 125 head for maximum compression" or so the video guy claims. I know the wave is just a newer version of the cub, but i'm wondering if anyone knows how compatible the engines are with c70 or ct90 /110 frames?
It kind of makes sense that teh c70 would have higher compression. both the c70 (70cc) and ct90 are rater at a top speed of 50mph (even though lots of people can't get that high) even though the c70 is lacking 20cc's. the c70 also has a 3-speed vs the ct90's 4.
I'm not trying to build some crazy monster. It'd be nice to cruise at 50 comfortably and w/o burning up the engine. having to switch to premium due to the higher compression isn't gonna make much difference with 100mpg, so no woes there.
Thanks!
"The C70 cylinder head has bigger valves and a hotter cam than the C90 one. You are in posession of the "Holy grail" of Honda Cub cylinder heads. If one were to want to "tune" a C90, fitting a C70 head would be a good first step.
As I recall, a C90 barrel and piston ought to fit.
Oddly, the sky's the limit with tuning that particular engine. Depends how much work you want to put in and how much money you have. The basic engine is the same as they use in (proper) monkey bikes so there is a large aftermarket spares/accessories availability.
The 110cc conversion is popular (you need to TOTALLY strip the engine so the crankcases can be machined out bigger to take the larger barrel). You can have race cranks, hotter cams, nitrous kits, DOHC cylinder heads. You name it, it's out there. They can be made to do in excess of 100mph if you have the funds and expertise.
My two suggestions are not to do with tuning though. If it's for a field bike, look into fitting an MTX125 front end and check the frame has been welded up where it joins the rear mudguard (under the back edge of the seat, look up under the mudguard with a torch). May already have been done, but they can break in half otherwise when abused (it's just pressed together as standard)."
I didn't find anyone talking about head swaps on this board so i was curious to get some more input. I found a video on youtube of a "fast honda cub" that has a "wave 125 head for maximum compression" or so the video guy claims. I know the wave is just a newer version of the cub, but i'm wondering if anyone knows how compatible the engines are with c70 or ct90 /110 frames?
It kind of makes sense that teh c70 would have higher compression. both the c70 (70cc) and ct90 are rater at a top speed of 50mph (even though lots of people can't get that high) even though the c70 is lacking 20cc's. the c70 also has a 3-speed vs the ct90's 4.
I'm not trying to build some crazy monster. It'd be nice to cruise at 50 comfortably and w/o burning up the engine. having to switch to premium due to the higher compression isn't gonna make much difference with 100mpg, so no woes there.
Thanks!
