56mm piston for a 110, any info wanted

[Mr_RPM]

i have been doing alot of research and cant find much

whats the max i can bore a stock atc110 sleeve
i found a piston thats 56mm, 4 bigger than stock. making it around 125cc its also high compression

i wanna buy a used cylinder and bore it to size and hope it works, but i dont wanna buy a cylinder and piston unless someone has done this before.

any info would br great!

[Vealmonkey]

+4 is pretty much the max. Not even an overbore for that piston. I hope you have a machine shop that is really good, because if they are not, then that cylinder will be ruined. You can go bigger, but you have to resleeve and you have to use a motorcycle piston. They are out there, but you need to do way more research if you want to start getting into the real performance areas. There are tons of little tricks, but you need to do research on them also. I just can't go giving all the really hot secrets to everyone! Saying a "High Compression Piston" is like saying a "Racing Cam". Do you know your compression. If not, then you won't know what octane fuel to run and you stand a big chance of ruining that cylinder and piston right away. Also, you need to know what cam you are going to run and you need to start making sure your valves clear your piston. With some cams, the valves will clear and some won't clear the valves. It won't take you very long to figure out your valves aren't clearing when you start the engine. Also you will need to run a bigger carb and intake, maybe. You can often get away with a stock carb with bigger jets if you aren't running much for a cam. And if you aren't going to port your engine any, a big piston and cam and carb won't really matter as all that extra fuel and air really won't enter your engine very efficiently anyway. It's way more complicated than just a piston. Save your money would be my best advice for you.

[Mr_RPM]

lol, my dad is actually the lead mechanic at one of michigans leading dealers, we know how to build a engine and have done it many times, i just wanted to know if it is possible to bore that sleeve that much, its hard to find specs on the max bore, we have a really good machinist and after reading this ill prolly take my chances and do it, if the cylinder gets ruined then no big deal, ill just go back to my original cylinder (ill be doing this bore on a spare cylinder.) the compression is 10.5:1 im aware with all the octane stuff and the valve piston clearence issues with new cams, and other cam issues. this will be all experimental and a good learning experience, because we havent built a 110 engine before and the dealer we work at doesnt take them in.
simply just wanted to know if i can bore that big, and you say its the max, so i take its possible then, ONE more thing. the only reason im going this big is because its the only high comp pistomn i can find, otherwise i wouldent go so big, anyone know where one is at?

im not looking for an extream racer 110, just a mild hop up since we are replacing the whole engine anyway. figured a high comp piston, pipe, cam, and bit of intake mods would be good, we can port n polish the intake too, and of corse rejetting and needle adjustment. and everything else needed to go with it, like higher octane and such.

[trizilla]

to answer your question, yes you can bore your stock cyl out to 56mm. thats it as far as boring but it can be done. i have 2 of these sitting on a shelf..:D