Cylinder Porting DIY
- Thread starter OConnor Racing
- Start date
Excellent videos Ken! I have some port work that was done by Angus and he did a great job...so i expanded upon his porting by just sanding the inside of the exhaust port with 220, then 400, and lastly 800 grit sandpaper by hand. Then i polished it up with the dremel. So the slicker the better? It's a mirror finish if you can't tell by the crappy pics. what about the other ports? I will do them to a mirror finish as well...seems if the air has no drag on it then it should be easier to flow through and make more power, right? Or should i stop here...
As I understand it, you do NOT want a mirror finish on the intake, only the exhaust. I've heard that a rough surface on the intake helps to atomize the fuel mixture. I would assume the same would be true for the transfer ports.
BTW, this may be my favorite thread on BF. Thanks Ken.
BTW, this may be my favorite thread on BF. Thanks Ken.
That is what I was thinking V...I know a mirror finish on auto cylinder heads are a no no. I wish I could get some dyno numbers on the mirror finish concept vs rough cut to see how far the power degrades.
I' stoked that so many peoplr have jumped on the porting band wagon. It' good simple info Ken gives you. Lets get to porting those jugs. I really like what the change did to my engine. It did take a little off the bottom but I think it doubled it and put it on the top. With Kens head design and his porting video I'm a happy Blaster owner.
Well you can always compensate the low end power by doing sprocket changes. Granted it will take away from some of the top end, but whatever riding style you choose for a given day then swap out the sprockets and go. Just takes a few minutes for the front sprocket change. This way you will have power all the way around. That's my easy cost effective fix for the low end suffer
Sorry I missed this. Just got back from PA. DON'T polish the intake ports!! Just smooth them out and bead blast them. Fuel will tend to ball up on polished ports.
hi is it worth the work with my setup?
my setup:
stock carbu
rino exhaust
14t sprocket
twin air filter
and is it for every 2-stroke bike the same?
always 1mm at the exhaust??
grts pastranafan
my setup:
stock carbu
rino exhaust
14t sprocket
twin air filter
and is it for every 2-stroke bike the same?
always 1mm at the exhaust??
grts pastranafan
180 grit is too fine IMO. don't go over 120 grit. 80 grit is good enough for intake and transfers.
guys, only polish the exhaust port!!
The 1mm works for the Blaster but it's not something you want to start doing to every cylinder. Cleaning up the factory snot in the ports is always a good idea no matter what kind of engine you have.
Exactly. Depending on the build and pipe being ran, you need to know if you even need more duration/port area. If you don't need more area or duration, then no sense in raising the exh port and taking away from the bottom end.
my question is with raising the exhaust port 1mm have a big affect on loosing the lower end? i know it will loose some but i really dont want it to be a light switch on/off the power. i am assuming?? that the 1mm is a good balance??
I left the intake porting out for a reason. It's way too easy to screw up your cylinder if you just go in and start cutting. If you want to try it, I suggest you start on a junk cylinder and get some practice. Don't remove any material from the bridge width but you can try to give it a wedge. You can open up the sides .5 mm, raise .5 mm and drop 1mm. Be sure to keep the lines straight. You can also lift the boost port .5mm but be very careful not to widen it or you'll stick a ring. This is still some mild porting. You're going to lose a little low but pick up a bunch of mid and top. It's worth the trade. Much broader power. You can also bore the carb 1mm bigger. This porting ( exhaust, transfers and intake) works well with the Toomy or FMF pipe, bored carb and head mod. Be sure to poke a few (8) ¾ “ holes in the top of the air box lid also.
