Alright guys Wanted to know a little about possibly porting out the exhaust port on my original 50cc cylinder. Obviously it's not anything to go fucking around with but was just wondering if someone could give me an insight on how I should go about doing it? Picture of it below.. Cheers.
copy the size/shape of the internal diameter of the exhaust stub onto the barrel and shape it the same (make sure theres enoth meat on the exhust port first so you dont end up going all the way through. try and keep the angle the same tho unless your enlarging it both internal and on the manifold? if your just opening it up to match the exhaust and not actualy working on the internal port/s your not going to see much of a difference
To be perfectly honest with you mate, I know fuck all about porting lol. All I know is that my mate shoved a drill up his on his rox and it went like fuck lol but he didn't care about his engine. Personally if it was me, id whip the barrell off and do it, but i'm not exactly sure on porting it.. you can see a black mark on the manifold now on where it needs opening up, but it doesn't need opening up all the way through right? Sorry if I seem like a downer.. just don't wanna do something wrong lol.
you work it deeper and deeper to attain the correct angle inside the exhaust port, making it that size is easy, doing it nicely is different
my m8 had this on his rox 50 but after we changed it we didnt see much of a difference but then again it was 3 years ago and we didnt realy know what we were doing LOL :w00t:
Would opening it all the way up straight through to match the exhaust's shape and size just fuck it up all together? Or minor, do you mean follow the original angle that it is now but make it larger?
try not to alter the port position in the barrel to begin with, just open up to match to the pipe then once you've got that nice you can look at lifting the exhaust port slightly.
DEFFO match that up to your exhaust! chemical metal/ jb weld on the outside of the tract would be a good idea aswell as there prob that shape for a reason! ( ie ; easier/cheaper to cast with less material!! ) once it flows nice id widen the exhaust port next, id try the suggested 68% of bore to start with! just try not to raise it as yo do this, and retain that curving edge at the top of the port to retain blowdown timing, two little mods that will see ALOT of difference!!
did some work on a morini barrel the once and the exhaust tract looked just like the one in the picture above, just simply matching it to the exhaust and making it the right shape, angle, gave a genuine 5mph more than before! and more accel of course!!
firtst off.. whoever keeps telling people the SAME thing just go away... ye 68% of the piston diameter, 1mm raise.. FUCK ALL IDEA WHAT YOUR DOING. could be too high already? whats the point ether way? ported 50's DONT LAST.. its that shape for a reason, to bring power down to that of a moped, it CANT exceed 3.5bhp.. with this modded it will do. same wiht the piaggio barrels being stupidly undermachined in the exhaust port.. literally cast bored machined and out the door. a match on even a piggy barrel makes it SO much crisper.. basicly DONT touch the internal's ATAL... its HARD, it WONT be even, it WILL be worse.. not just a case of widening and raising, theres the blowdown timing, crescent, edges vs the centre offset, allsorts. wihout somone atleast showing you a few things in person i wouldent advise ANYONE works on the internals of a barrel they intend on using. experimentation yes, as for hackin your only form of transport about cos somone on a forum said "ye 68% of the bore@ is NO way to go about things... just a reminder of the rules.. DONT GIVE OUT BAD ADVICE, this means if you have done it, suceeded and sone a correct job of it then feel free to recomend things.. if youve never done it or had shit results/short lifew from parts just shut up.. easy really
right i know thats aimed at me but i aint gave no bad advice out! read my second posst.... i did try... i did succeed with very good results! so yea i hope i would be allowed to give out advice. i know im not a big name on this site, but i do know what im talking about, aint looking to start a arguement so i will just leave it, and take my so called "Bad Advice" some where else then.........
If it was me i would just blend it in so at the exhaust port end it was as round as you could get it with out breaking through the metal As minior says unless you know what you have now you dont know how much to change to make it better Making a difference to the power is not hard making a difference thats actually better is alot harder
sorry about not posting back my laptop chargers given up, gonna go with the advice to just round off the exhaust port rather than touching the internal part of the barrell, is alot of difference expected from just rounding it off? and to do the job, will a drill do it or are we talkin the use of a dremel?
